Altitude hold + Zlog mod3 & mod4 working

[eladiomf]

Hello

I have design an altitude hold device. For sensing altitude it uses Zlog mod 3 altimeter thought it's serial interface.

I have done first flight today with great results.

It uses 3 channel to connect to receiver: first channel (proporcional) for servo control (elevator or throtel), second channel (3 positions) for manual, automatic mode o preset mode and a third channel (proporcional, I use a dial channel) for setting the altitude in the preset mode.

In manual mode you control the servo.

When you activate the automatic mode this your actual altitude is the reference altitude.

In preset mode you set your desire altitude with a dial channel. You can set an altitude betwuin 50 a 1000 meters or feet , and the plane would go to that altitude.

I will post more results in next days.

Excuse my poor english, I'm from Spain

EDIT: Actually AltHold is tested also with Zlog Mod4, so I have changed the Thread's tittle.

[Tom Harper]

Very impressive!!

Tell us more. Your English is fine.

[LukeZ]

Looks great - was jut a matter of time before someone did this. Good job.


Luke

[eladiomf]

I will make a more extensive description.

I have use a PIC16F876 and I have program it in Pic Basic Pro. I have inspire my design in the RCAP autopilot.

The board have 2 variable resistors. One to set the gain an another to set the max travel of the servo.

Also have 2 jumpers, one to selec the direction of travel of the servo. With second jumper on I use the RX's power to power the board. If I want to use external power, I take of the jumper. The board have to holes to solder 2 wires for the external power. Acctually I'm using RX's power.

The board connect to Zlog through 2 conectors, power to the Zlog and TTL interface.

There are 4 servo cables. One to connect the servo to the board, second to connect the board to elevator o throtel channel, third to connect to an aux channel (in my case channel 5) to select the mode of operation (manual, automatic or preset mode) and the four connections is to another aux channel (in my case channel 8, an dial channel) to set the wanted altitude.

The board also have a led to indicate the mode of operation.

[eladiomf]

Modes of operation:

Normal Mode:
This is a pass throught mode or manual mode. You control the altitude servo manually and the altitude hold make nothing.
To select this mode the pulse of aux channel 1 must be <1.5ms
In this mode the led is always off

Automatic mode:
When you engaged this mode your actual altitude is the reference altitude. The plane will keep the reference altitude as it is in this mode.
To select this mode the pulse of aux channel 1 must be >1.5ms
In this mode the led make a quick flash every second

Preset mode:
In this mode you can set the plane to go automatic to the altitude that you want. To set this altitude in flight I use an aux channel 2 (a dial channel). With this channel I can set a wanted altitude bettuen 50 and 1000 meters of feet (What ever the Zlog is configured to). When I want to ascent or descent to an altitude in automatic mode, I simply have to rotate the dial channel. The pulse of aux channel 2 is the wanted altitude (1.05 ms for 50 meters and 2.00 ms for 1000 meters)
To select this mode the pulse of aux channel 1 must be >1.8 ms and the pulse of aux channel 2 must be >1.05 ms.
In this mode the led is half a second on and half a second of.



There is also another function of the led, when there is not connection to the Zlog or the Zlog is not sending signal, the led is always on.

Now I'm at work. When I get home I will post the configuration of the Zlog.

Eladio

[Tom Harper]

Fantastic!

Your English is commendable.

[JeffElecRC]

This is a great project. I'm impressed by the 3 modes and attention to detail you've provided.

Will you be making the Basic code available, I'm interested to see your control loop? Or do you plan to sell this as a kit and prefer to keep your code secret?

[workshop]

You should contact Hexpert systems and see if they'll help you manufacturer and/or sell this on their website (unless you have bigger plans). You've come up with a really neat tool especially since many clubs are now limited to 400' AGL. I heard (edit: a rumor, later proved false,) that a Police helicopter landed at El Dorado Park in Long Beach a few months ago to hand out tickets for flying higher than 400'.

Your AltHold is needed. You have fans!

Jeff
www.teslacoil.com

[Kilrah]

Cool!
Now to the bad part: Hexpert Systems now ship the Zlog MOD 4. That one doesn't have the serial connector anymore, but the board now directly has a mini-USB connector. We'll have to find out if there's a point we could still grab serial data from. That's bad news for DPCAV's Vizion too...

[MX]

Cool!
Now to the bad part: Hexpert Systems now ship the Zlog MOD 4. That one doesn't have the serial connector anymore, but the board now directly has a mini-USB connector. We'll have to find out if there's a point we could still grab serial data from. That's bad news for DPCAV's Vizion too...

No, we decided to leave the connector on the MOD4. Same place and pinout as MOD3, so Vizion will still work.

MX

[MX]

...neat tool especially since many clubs are now limited to 400' AGL. A Police helicopter landed at El Dorado Park in Long Beach a few months ago to hand out tickets for flying higher than 400'.


Jeff
www.teslacoil.com

On another note, I've been developing an altitude cutoff version of the ZLog. Targeted for limited motor run contests, it cuts off the throttle at a preset altitude. With a config change, could easily be setup to cut throttle when you hit your altitude ceiling and reenable throttle maybe 50 feet lower or something like that.

MX

[eladiomf]

In order to function with AltHold, Zlog must be configure to 19200 baud.

To set my Zlog to 19200 baud, I used the botton's menu. I think that you can not set the baud rate with the PC aplicattion. Maybe MX can explain this better.

For the rest of the settings I use the PC aplicattion of Zlog.

Altitude can be set to feet or meter, what you prefer. But its set to meter it would have less sensitivite, so you would have to put the gain higher.

I set Zlog to Autozero on start up, so that AltHold function well in the preset mode.


Eladio

[eladiomf]

You should contact Hexpert systems and see if they'll help you manufacturer and/or sell this on their website (unless you have bigger plans). You've come up with a really neat tool especially since many clubs are now limited to 400' AGL. A Police helicopter landed at El Dorado Park in Long Beach a few months ago to hand out tickets for flying higher than 400'.

Your AltHold is needed. You have fans!

Jeff
www.teslacoil.com

The AltHold is working very well for me, but I would like that more people will test the device before make a commercial unit.

If there is enought interest, maybe I can make some kits or asembled an test unit (what people prefer), so that some beta testers can test the AltHold and post their results and posible improviments.

See you

Eladio

[MX]

In order to function with AltHold, Zlog must be configure to 19200 baud.

To set my Zlog to 19200 baud, I used the botton's menu. I think that you can not set the baud rate with the PC aplicattion. Maybe MX can explain this better.

For the rest of the settings I use the PC aplicattion of Zlog.

Altitude can be set to feet or meter, what you prefer. But its set to meter it would have less sensitivite, so you would have to put the gain higher.

I set Zlog to Autozero on start up, so that AltHold function well in the preset mode.


Eladio

Yes, you can only set ZLog's baud rate using the display and buttons.

MX

[MX]

The AltHold is working very well for me, but I would like that more people will test the device before make a commercial unit.

If there is enought interest, maybe I can make some kits or asembled an test unit (what people prefer), so that some beta testers can test the AltHold and post their results and posible improviments.

See you

Eladio

I'd be glad to test one with both MOD3 and MOD4 units.

MX

[d_wheel]

The AltHold is working very well for me, but I would like that more people will test the device before make a commercial unit.

If there is enought interest, maybe I can make some kits or asembled an test unit (what people prefer), so that some beta testers can test the AltHold and post their results and posible improviments.

See you

Eladio

Be glad to test one on one of my uav's. The kit version would be fine.

Later;

D.W.

[JeffElecRC]

I too would be glad to beta test.

Regards,
Jeff

[MX]

No, we decided to leave the connector on the MOD4. Same place and pinout as MOD3, so Vizion will still work.

MX

Just noticed something. On the MOD4, the 3-pin connector comes off the bottom. That way the user can read the silkscreened pin labels on the top of the PCB. This won't line up with your 3-pin socket. You might leave it as an option to put the 3-pin socket on the bottom to line up with MOD4 ZLogs.

MX

[workshop]

MX - Thanks for thinking of DPCAV and his customers.

The 400 foot issue is of huge concern in So. Cal.. In fact, I'm giving a talk on altimeters at my club meeting on the 7th. Since I'm brand biased (I've purchased 2 Z-Logs so far) :rolleyes: I be sure to cover the Z-Log. I see a big demand for the combination of Z-Log/Alt Hold and the feature set you've touched on.

I Beta test too!

Jeff

[eladiomf]

Hello

MX, can you post a picture of the serial connectors in Zlog Mod 4?

No problem leaving the connectors without soldering. I think that people around here prefer a kit than a test unit.

For now there a 4 beta tester I will wait a couple of days an placed an order for the components and calculate the cost of the kits.

In next day's I will make and post a set of schematics of component placement.


Eladio

[riosouza]

A Police helicopter landed at El Dorado Park in Long Beach a few months ago to hand out tickets for flying higher than 400'.

Jeff
www.teslacoil.com

Sorry my question out of the topic.
Jeff, could you tell me where saw the Eldorado police give out ticket for flying above 400' AGL ?
I would like to know if it's an AMA rule, or Law. :confused:
I heard, it's a rule, but to get a ticket only if it was a Law.
I want to know more about it.
If it's true, I offer my sincere apologies in advance. :(

[workshop]

El Dorado Regional Park is within three miles of the Long Beach, CA Airport.

I would imagine there are laws about flying around airports, even if one flys from an AMA field.

You may want to search out the officers of this club for official confirmation of the event and the repercussions.

http://www.1hss.org/edsf.htm

Jeff

[ClayH]

Jeff,

I don't know where you got your information about tickets being handed out recently at El Dorado Park for altitude infractions, but that is blatently false. I fly there every weekend and have spearheaded the effort to return EDSF to a glider friendly environment after our run in with the FAA nearly three years ago. If any such incident happened, it would have been big news at our field as many feel we are only one such incident from being shut down.

Is it possible that this could have happened at HSS where the helicopter pilot and the fliers have a more adversarial relationship? If you have first hand knowledge of this event, please pm me with details, as I'd want to know more. Otherwise,I'd request that you edit your statements in this thread refering to EDSF. We don't need any bad press right now.

Best regards,

Clay Hollingsworth
Director of Glider Operations
EDSF

[workshop]

Clay,

I got the information from the counter employees at Hobby People in Lawndale. I usually regard them to be accurate providers of information regarding our hobby.

I'm sorry for passing on bad information. I called a couple of guys in my club and they "remember" this too. Perhaps EDSF should distribute flyers to local hobby shops to correct what seems to be a solid urban myth.

I made edits to two posts to help you dispel the rumor.

Jeff

[ClayH]

Jeff,

Thanks for the quick follow-up. I will contact all of the local Hobby People locations to clear up the issue and to let them know about all of the new soaring activity we have planned for this year.

On a related topic, lots of guys at our field have ordered altitude measuring devices in order to get a better feel for the 400 foot ceiling. I bought a Ram 2 and am now using a Picolario that gives me real time altitude,rate of climb and voltage verbally over a walkie talkie. It's a great teaching device as I can ask people to guess how high I am at different spots all over the field and then I hit a switch and get the answer! It's expensive for the average flier,but an investment I decided to make in order to prove to the many detractors that we could enjoy soaring below 400 feet.

Many guys have ordered the How High as well. It's great to see so many members taking an active roll in acurately monitoring the 400 foot ceiling!

Lastly Jeff, the EDSF club meeting is also on Feb. 7th. Is that where you are speaking?

Clay

[workshop]

Clay,

I'll be discussing the Z-Log, How High and Picolario at the Peninsula Silent Flyers meeting (first Wed. of every Month). I'm the newsletter editor (I'm embarrassed to say after spreading the helicopter rumor) and I cover technical and electronics issues for the club.

In an act of contrition, if you make an official statement for the Hobby Stores, I'll be happy to publish it in next week’s newsletter. :o

Jeff

[workshop]

:) :) :)

[ClayH]

No further contrition necessary,but once I confirm my info, I'll send you a PM with my statement for the LHS.

Thanks Jeff. BTW, where do you guys fly? Do you fly 3 meter there?

Clay

[workshop]

Small electrics at Entradero Park in Torrance and Gliding at Del Cerro Park in Palos Verdes.

Jeff

[David_Naseef]

Something strange about the preset mode.
Suppose you were at 20 m altitude. How could you reach 1000m by elevator control alone?
There should be another channel increasing throttle. Correct me !

David

[eladiomf]

I have my AltHold connect to throttle channel. Elevator is always neutral. My test plane is very stable, is a Twin Star I from Multiplex. AltHold will increase the throttle and the plane will go up.

In a less stable plane you will need a FMA copilot.

I have not test yet AltHold connect to elevator.

Eladio

[Kilrah]

No, we decided to leave the connector on the MOD4. Same place and pinout as MOD3, so Vizion will still work.

MX

Oh yeah the footprint is indeed here. The connector is not fitted though, so I didn't notice it ;)

[UC_A_P]

Eladiomf i would be very interested in testing or even purchasing one of your althold devices as it would be of great use to me also would it work as well in a helicopter any coment would be greatly appreciated thank you in advance

[eladiomf]

Eladiomf i would be very interested in testing or even purchasing one of your althold devices as it would be of great use to me also would it work as well in a helicopter any coment would be greatly appreciated thank you in advance

Hello

I have place an order for components to offer a few kits. I can send you a kit if you want test it.

I have not test it in a heli, but I think that it would work very well connected to the pitch servo. (Of course the heli can not be CCPM). It is very sensitive (1 feet), so I think it will keep the altitude in a stacionary well.

[Wmacky]

I'm interested in a kit too!

[Crash Pilot]

Looks Good

I would also like to test.


Crash Pilot

[d_wheel]

Hello

I have place an order for components to offer a few kits. I can send you a kit if you want test it.



Do you know the cost yet? I will be happy to pay you in advance if that will help. If you don't have a paypal account, I will be happy to send you a money order. I am sending a private message with my address.

Later;

D.W.

[eladiomf]

Do you know the cost yet? I will be happy to pay you in advance if that will help. If you don't have a paypal account, I will be happy to send you a money order. I am sending a private message with my address.

Later;

D.W.

I have a Paypal account.

Acctually I'm preparing schematics and documentation.

I have place an order to digikey for the components to make 10 kits. One of the kit is for you. I have not calculate cost yet.

I have a isolator, so PCB's will be home made.

When all is ready, I will give my paypal details.


Eladio

[d_wheel]

I have a Paypal account.

Acctually I'm preparing schematics and documentation.

I have place an order to digikey for the components to make 10 kits. One of the kit is for you. I have not calculate cost yet.

I have a isolator, so PCB's will be home made.

When all is ready, I will give my paypal details.


Eladio

Thank you. I have one of my planes primed and ready for the test.

Later;

D.W.

[UC_A_P]

Thank you very much Eladio I also have several fixed wing designs i use as well all of wich are very stable so as soon as you have a price set i will ensure you a speedy paypal transaction now will the devices come in kit form or assembled and the software used to program is it provided or is it something i will need to download thank you in advance for any response

John Rybacki II
Manager U.C. Aerial Photography Llc.

[icebear]

Eladio,

If you haven't yet got testers for all your units, I'd be happy to test one of them in my Supermiss UAV. I have the Zlog MOD4 already.

Thanks,
/Bjorn

[eladiomf]

I have almost finish shematics, I will post them in a few days.

I have also finish the boards, I only need to drill them.

I'm preparing 10 units. This is the order list for Beta testers:

MX
d_wheel
JeffElecRC
workshop
UC AP
Wmacky
Crash Pilot
Icebear

Excuse the delay, but I have a couple of modifications in the board, so that it can acommodate future firmware upgrades.

Eladio

[workshop]

:( um... did you forget someone?...

Jeff (in the Tesla coil workshop)

:D

[eladiomf]

:( um... did you forget someone?...

Jeff (in the Tesla coil workshop)

:D

Sorry Jeff, I forgot you. I have now add you to the list.

I'm also following your proyect (Catalina Island).

Eladio

[d_wheel]

I have almost finish shematics, I will post them in a few days.

I have also finish the boards, I only need to drill them.

Eladio

Happy to hear you are making progress. Have a good day.

D.W.

[icebear]

I have almost finish shematics, I will post them in a few days.

I have also finish the boards, I only need to drill them.

I'm preparing 10 units.

That was really quick - great! Looking forward to hearing more about this unit..
/Bjorn

[UC_A_P]

Thank you very much Eladio im am eagerly awaiting and am greatly appreciative of the hard work you are doing
John

[rclinks2002]

I would love to Beta test the altitude hold. I have a UAV project that this unit would work perfectly in. Please let me know
Ben

[eladiomf]

I have create a little web page with a description of component placement, and instrucctions to set AltHold.

Please, ask me if something is not clear.

http://alai.h3m.com/~s0350672/althold.htm

I have also received the parts from dikikey, and have the boards ready. So, I will start to program pics and prepare the kits.

I have calcule the cost of kits, and have make 3 options, so is easy for everyone:

1) Board, all the parts, connectors and jumper. WITHOUT servo cables.

2) Board, all the parts, connectors and jumper. WITH servo cables (3 males and 1 female).

3) Fully asembled unit, ready for use.

I have also calculate shipping cost (Certificate) to Worldwide:

1) Normal shipping

2) Express shipping


People interesting in a kit, Email or PM with your shipping address and I will reply with my Paypal details.

[d_wheel]

Great news! I have sent you a private message.

Later;

D.W.

[Vince53]

Sending PM,

Vince

[icebear]

Great! PM sent!
/Bjorn

[UC_A_P]

sent pm

[ThaiskyDigital]

Sent PM

[Gary Mortimer]

pm a for away

[eladiomf]

Good news

The kits and assembled units are ready for ship.

Excuse the delay, but i have been very busy lately.

I have still a couple of units left.

I have PM to all the people interesting in one unit with my Paypal details. If I have forget anybody, please tell me.

All the units are with the new board, that have some free holes for future firmware upgrades.

I hope that you like the work.

Eladio

[DiveBombDave]

PM sent, please have one left! :)

Dave

[hihptsi]

so has anyone Tried it out yet?

id like to know how well it works holding your altitude.
im going to have mine Activated with My unav RTL so incase my berg7p goes into failsafe while flying FPV,it will lock its altitude with the elevator,motor will throttle up to 75% or so and the RTL will steer the rudder home while the copilot gives roll stability.


i hope this works well becaues it sure is priced right...compared to the ALT3,etc.

take care
walter

[eladiomf]

Hello

Tomorrow I will PM to all the people that have send Paypal Payments.

Now is late here, and I'm going to sleep.

I will start shipping in Monday morning.

Eladio

[Vince53]

Walter,

Is it your intent to have only the altitude hold on the elevator and not the copilot? If using both on the elevator how are you going to integrate them?

I am hoping to have both hooked to the elevator depending on the situation; normally the Copilot will have control, Altitude Hold will only be connected to the elevator servo when altitide control is called for. I bought a subminiature relay with 5v coil and am hoping to switch the signal wire to the elevator servo as needed. The relay coil will be controlled by an electronic switch tied into mode channel for the Altitude Hold; >=1.5ms pulse. I just got the parts yesterday and tried sketching it out tonight, maybe a test setup over the weekend. I'm interested in hearing if you have another way of integrating the Altitude Hold with the Copilot.

Thanks,
Vince

[hihptsi]

Walter,

Is it your intent to have only the altitude hold on the elevator and not the copilot? If using both on the elevator how are you going to integrate them?

I am hoping to have both hooked to the elevator depending on the situation; normally the Copilot will have control, Altitude Hold will only be connected to the elevator servo when altitide control is called for. I bought a subminiature relay with 5v coil and am hoping to switch the signal wire to the elevator servo as needed. The relay coil will be controlled by an electronic switch tied into mode channel for the Altitude Hold; >=1.5ms pulse. I just got the parts yesterday and tried sketching it out tonight, maybe a test setup over the weekend. I'm interested in hearing if you have another way of integrating the Altitude Hold with the Copilot.

Thanks,
Vince


i was just gonna try putting the altitude hold inline with the copilot.on the elevator channel.if this does not work i will just use the altitude hold on the elevator channel and disable the elevator function on te copilot.

anyone wanna chime in here ..

[eladiomf]

Walter,

Is it your intent to have only the altitude hold on the elevator and not the copilot? If using both on the elevator how are you going to integrate them?

I am hoping to have both hooked to the elevator depending on the situation; normally the Copilot will have control, Altitude Hold will only be connected to the elevator servo when altitide control is called for. I bought a subminiature relay with 5v coil and am hoping to switch the signal wire to the elevator servo as needed. The relay coil will be controlled by an electronic switch tied into mode channel for the Altitude Hold; >=1.5ms pulse. I just got the parts yesterday and tried sketching it out tonight, maybe a test setup over the weekend. I'm interested in hearing if you have another way of integrating the Altitude Hold with the Copilot.

Thanks,
Vince

I have my Copilot connect to elevator and AltHold connect to trothle, and it's working great for me.

Copilot take care of quick changes in the altitude and AltHold take care of slow changes in the altitude.

If you are going to use both in elevator maybe an option is an v tail mixer: 2 inputs and use only one output.

Eladio

[Vince53]

Eladio,

It sounds like there may be many options for hookup and success may depend on the gain settings of the devices. I was attempting to avoid an interaction of the Copilot and Altitude Hold but that may not matter, depending on the gain settings and time constants of each device. I see a lot of experimentation ahead!

Vince

[DiveBombDave]

It seems like the unit is designed to either pass the servo signal through, or take over when activated to control the channel (and therefore ignore it's input). This makes me think it would be fine wired in sequence with the copilot controlled elevator. Deactivated, copilot controls elevator. Activated, it controls elevator.

The difference on whether to use it on throttle or elevator is if the plane will naturally climb with throttle. Some planes are setup to only go faster with throttle and need the elevator to climb. My telemaster electro fits in the former category.

I wonder if they got shipped out today; can't wait.

Dave

[eladiomf]

Hello

Units have been ship today to all the people that have already send the payment.

I suppose you will received them in 7-12 days.

I will waiting for yours reports.

I would like that people that are going to connect it to elevator, post their results.

Eladio

[hihptsi]

Hello

Units have been ship today to all the people that have already send the payment.

I suppose you will received them in 7-12 days.

I will waiting for yours reports.

I would like that people that are going to connect it to elevator, post their results.

Eladio


i definatly will let you all know how it works for me,although its gonna take a few weeks before i have anykind of flight report to share.im still putting together my airframe and still assembling all the rest of the little stuff.

as i stated earlier i plan to have a copilot controlling the elevator and the aleirons,the Altitude hold will be inline with the copilot on the elevator.

i will have a U-NAV RTL installed onto the Rudder channel as well.

if my aircraft happends to go into failsafe the Copilot will hold roll stability while the Alt hold locks the altitude and the RTL Steers the rudder till it comes home.

i hope this works out as good as i Think it will.

i plan on doing my testing on my land in Wisconsin so i should be able to do some comprehensive analysis.

[ThaiskyDigital]

plan on doing my testing on my land in Wisconsin
You and me we are in very far away.

But it make me excite, I plan to have the same set up as you have.
I do have U-Nav RTL also.
Today (Monday) Eladio will sent two set to me and I will try to test it as same way as "hihptsi" . Let see the result, Wisconsin and Thailand.

[d_wheel]

In order to function with AltHold, Zlog must be configure to 19200 baud.

To set my Zlog to 19200 baud, I used the botton's menu. I think that you can not set the baud rate with the PC aplicattion. Maybe MX can explain this better.

For the rest of the settings I use the PC aplicattion of Zlog.

Altitude can be set to feet or meter, what you prefer. But its set to meter it would have less sensitivite, so you would have to put the gain higher.

I set Zlog to Autozero on start up, so that AltHold function well in the preset mode.


Eladio

I noticed that you have the "auto start recording" and "auto stop recording" turned off in the Zlog configuration. Is this necessary when using it with your altitude hold board? I would like to make recordings to view later and see how well the altitude held if possible.

Later;

D.W.

[eladiomf]

I noticed that you have the "auto start recording" and "auto stop recording" turned off in the Zlog configuration. Is this necessary when using it with your altitude hold board? I would like to make recordings to view later and see how well the altitude held if possible.

Later;

D.W.

You can turn on the "auto start recording" and "auto stop recording" if you want. I have them turn off because I usually don't look data in the computer after flying

Eladio

[d_wheel]

You can turn on the "auto start recording" and "auto stop recording" if you want. I have them turn off because I usually don't look data in the computer after flying

Eladio

Thank you. Have a great day.

Later;

D.W.

[hihptsi]

Thank you. Have a great day.

Later;

D.W.


D.W. did you get your unit in hand yet?let us know how well it works. :D

walter

[d_wheel]

D.W. did you get your unit in hand yet?let us know how well it works. :D

walter

No it hasn't arrived yet. Still waiting anxiously like everyone else. If the weather cooperates, I should be able to fly it the same day (or day after) it arrives and will give a full report.

Later;

D.W.

[d_wheel]

Modes of operation:

Preset mode:
In this mode you can set the plane to go automatic to the altitude that you want. To set this altitude in flight I use an aux channel 2 (a dial channel). With this channel I can set a wanted altitude bettuen 50 and 1000 meters of feet (What ever the Zlog is configured to). When I want to ascent or descent to an altitude in automatic mode, I simply have to rotate the dial channel. The pulse of aux channel 2 is the wanted altitude (1.05 ms for 50 meters and 2.00 ms for 1000 meters)
To select this mode the pulse of aux channel 1 must be >1.8 ms and the pulse of aux channel 2 must be >1.05 ms.
In this mode the led is half a second on and half a second of.


Eladio

I do not have a dial on the transmitter that will be used for testing. If I use a 3 position switch with atv's set to 90% on the low end and 100% on the high end, will this give me an altitude of 100 feet, 500 feet, and 1000 feet at the 3 positions of the switch?

Later;

D.W.

[eladiomf]

I do not have a dial on the transmitter that will be used for testing. If I use a 3 position switch with atv's set to 90% on the low end and 100% on the high end, will this give me an altitude of 100 feet, 500 feet, and 1000 feet at the 3 positions of the switch?

Later;

D.W.

Yes you can use a 3 position channel.

The relation betwuen the ATV's and the altitude would be the following:

1000 feet 100% UP ATV
950 feet 90% UP ATV
900 feet 80% UP ATV
850 feet 70% UP ATV
800 feet 60% UP ATV
750 feet 50% UP ATV
700 feet 40% UP ATV
650 feet 30% UP ATV
600 feet 20% UP ATV
550 feet 10% UP ATV

500 feet CENTER OF SWICH (Center of Channel)

450 feet 10% DOWN ATV
400 feet 20% DOWN ATV
350 feet 30% DOWN ATV
300 feet 40% DOWN ATV
250 feet 50% DOWN ATV
200 feet 60% DOWN ATV
150 feet 70% DOWN ATV
100 feet 80% DOWN ATV
50 feet 90% DOWN ATV
Preset OFF >90% DOWN ATV

So, with 90% in the down side you get 50 feet. Set 80% to get 100 feet.

Eladio

[hfriling]

Has anyone tried the Barometric Pressure Sensor - SCP1000 on the Spark Fun website
(http://www.sparkfun.com/commerce/product_info.php?products_id=8161) in place of the Zlog?

eladiomf? how about you?

[eladiomf]

Has anyone tried the Barometric Pressure Sensor - SCP1000 on the Spark Fun website
(http://www.sparkfun.com/commerce/product_info.php?products_id=8161) in place of the Zlog?

eladiomf? how about you?

Sorry, I didn't Known that sensor. I will take a look.

But actually I'm very happy with the precision of the Zlog. It have a resolution of an feet and can also log your flight and see later in a PC. It's not expensive if you look all the functions that Zlog have. And already many people have it. Thats why I thought that was a great option for AltHold.

Regards

Eladio

[askman]

I got one of these devices coming as well. I too want to test it on a heli. I will use corona with copilot as initial test vehicle. (it is fixed pitch with throttle control for power) I have couple of bling coronas(one setup as AP) this should be much easier due to higher damping.(plus I have extra channels for control) if this is successful, i will want to test with CP heli, probably with ap2000i.

[hihptsi]

im very interested to know if anyone has done any flight testing with this yet??

please let us know how well it worked.and how you had it hooked up.

[d_wheel]

im very interested to know if anyone has done any flight testing with this yet??

please let us know how well it worked.and how you had it hooked up.

They are coming from Spain and have not had time to arrive. Don't worry, everyone will hear about the results within a day or two, weather permitting, of their arrival. I already have an aircraft set up and waiting.

Later;

D.W.

[icebear]

My Alt Hold arrived in safe condition last Friday - thanks Eladio!

The unit looks very neatly done and and I have decided to use my Wattage Super Imress II as a test bed. This plane is a very stable 4 ch trainer model with 44" wingspan and has a good roomy fuselage. I can recommend it to anyone who wants a good, light, stable electric for AP or projects like this.

I already had the Co-Pilot istalled from a previous project and it's just a matter of dropping the ZLog and AltHold in.

I also mounted the EM-406 GPS while awaiting the RCAP v3.

Hopefully I will be able to start testflying Monday-Tuesday since the weather looks good. Too windy today however :(

Results to be posted soon. Looking forward to reports from the other testers as well!

/Icebear

[d_wheel]

My Alt Hold arrived in safe condition last Friday - thanks Eladio!s as well!

/Icebear

I'm VERY jealous Icebear!

By the way, I couldn't help but notice the similarity of our avatars. Of course, yours is a real bear and mine kind of looks like one but a Bear by name only . ;)

Later;

D.W.

[icebear]

By the way, I couldn't help but notice the similarity of our avatars. Of course, yours is a real bear and mine kind of looks like one but a Bear by name only . And that happens to be my name too - but in my language :) ..!

Anyway - I did familiarize myself today with the AltHold.

Everything seems to be woring OK on the ground, except for my Co-pilot starting to act a bit funny. It is jittering the servos on start-up but then working ok. Anyone seen that before? My elevator servo seems to have been hurt by it because it jitters around a certain point or maybe that is the root cause...?

Just one question - the AltHold uses two channels for control. One 3-way to choose between Normal/Auto/Preset and one proportional to set the 'Preset' altitude

My radio has only 6 ch (Hitech Optic 6) and as I see it I can either go for;

a) Normal/Preset only (ch 5 switch on S2 and then ch 6 on S4 to set preset altitude)

- OR -

b) Normal/Auto only (ch 5 switch on S4 and ch 6 on S2 to engage into Auto mode)

As I see it there is no way to get all three modes on a 6 ch Rx with just a two-way swithc (ch5) and flap sliders (ch6)

Is this correct?

Thanks,

Icebear

[eladiomf]

And that happens to be my name too - but in my language :) ..!

Anyway - I did familiarize myself today with the AltHold.

Everything seems to be woring OK on the ground, except for my Co-pilot starting to act a bit funny. It is jittering the servos on start-up but then working ok. Anyone seen that before? My elevator servo seems to have been hurt by it because it jitters around a certain point or maybe that is the root cause...?

Just one question - the AltHold uses two channels for control. One 3-way to choose between Normal/Auto/Preset and one proportional to set the 'Preset' altitude

My radio has only 6 ch (Hitech Optic 6) and as I see it I can either go for;

a) Normal/Preset only (ch 5 switch on S2 and then ch 6 on S4 to set preset altitude)

- OR -

b) Normal/Auto only (ch 5 switch on S4 and ch 6 on S2 to engage into Auto mode)

As I see it there is no way to get all three modes on a 6 ch Rx with just a two-way swithc (ch5) and flap sliders (ch6)

Is this correct?

Thanks,

Icebear

Hi,

Yes you can use the 3 modes with a two-way swithc. Read the Instrucctions:

Preset mode:
In this mode you can set the plane to go automatic to the altitude that you want.
To select this mode the pulse of S2 channel must be >1.8 ms and the pulse S4 channel must be >1.05 ms.
In this mode the led is half a second ON and half a second OFF.


In your case, conect S2 to channel 5 and S4 to channel 6 (flaps):

Normal mode: Put channel 5 in the up position (1 ms)

Auto mode: Put channel 5 in the down position (2 ms) y channel 6 all one side (1ms)

Preset mode: Let channel 5 in the down position (2ms) and increase a little the channel 6 (> 1.05 ms).

Telling it in another form:

Channel 6 (1- 1.05 ms) auto mode

Channel 6 (1,05 - 2 ms) preset mode.

If it's not clear, tell me.

Regards

Eladio

[icebear]

Thanks a lot Eladio! I'll try that again (I tested but found that it entered only Preset and not Auto whatever I did with th ch 6 sliders) but I will do some more testing!

Hopefully I will be able to fly tonight...

/icebear

[Itzik Ronen]

Hi Eladio, I send you PM, I like to buy one of this units.
Can it work whit Zlog mod 4?
Thanks
Itzik

[ALtitudeap]

Eladio, If you decide to make this product commercial, I do assembly and distribution in the USA. I would however recommend going surface mount since that is what i primarily do.

Brian Carpenter

[eladiomf]

Hi Eladio, I send you PM, I like to buy one of this units.
Can it work whit Zlog mod 4?
Thanks
Itzik

I have not test with mod4, but it must work the same that with mod3, as both use the same serial interface.

PM send

Regards

[hihptsi]

Thanks a lot Eladio! I'll try that again (I tested but found that it entered only Preset and not Auto whatever I did with th ch 6 sliders) but I will do some more testing!

Hopefully I will be able to fly tonight...

/icebear


im eagerly awaiting your results icebear.

[icebear]

I just returned from a few short test flights with the AltHold unit.

It's getting dark early so I just managed two flights on my Super Impress II. My favourite farmer had fixed the'runway' for me for the season. He just earned som more AP's of his farm...:)

First impressions are that the unit works! I set the throw and gain to a little more than 50% and disabled the Co-pilot on elevator.

When enabled the AltHold seemed to immediately react to changes in altitude. On the second flight I enabled the Zlog data recording so here is a screen print of the data.

I flew circles using rudder under co-pilot control to see how the unit worked and as you can see it is keeping altitude well in spite of my rudder inputs. I would like to test different settings of course to see how that changes performance..

The first and last part of the recording is without the AltHold.

I did not have time to test the preset mode, but maybe later in the week.

Well done Eladio! Now I am eagerly awaiting the RCAP v3....

/Icebear

[hihptsi]

good to hear!
id be interested to see how well it holds the altitude in Straight and level flight.keep us posted!

Walter

[d_wheel]

When enabled the AltHold seemed to immediately react to changes in altitude. On the second flight I enabled the Zlog data recording so here is a screen print of the data.

/Icebear

Was the airplane porpoising up and down wildly, or does it just appear so on the graph? If so, it probably just needs some minor changes on the gain and/or control surface throw adjustments.

Later;

D.W.

[icebear]

Actually the porpoising wasn't visible to the eye. I could hear the motor changing speed but it felt more mild than the graph shows. I will test more gain settings to see how that changes things.

The winds were quite blustery too!

/icebear

[d_wheel]

Actually the porpoising wasn't visible to the eye. I could hear the motor changing speed but it felt more mild than the graph shows. I will test more gain settings to see how that changes things.

The winds were quite blustery too!

/icebear

O.K. So you had the altitude hold on throttle?

Later;

D.W.

[icebear]

O.K. So you had the altitude hold on throttle?

Later;

D.W.

Yes, that's right. AltHold on throttle and I did not engage copilot on elevator.
It seemed quite smooth in the air but I need to do some more testing. Very neat to have the Zlog record performance!

/icebear

[d_wheel]

The weather was so great that I could not resist the temptation and went flying directly from work today. Upon arriving home I discovered that the altitude hold board had arrived. After a quick meal, I soldered the connectors on and gave it a quick test. Everything seems to be working normally. Tomorrow after work I will install it in the test airplane as quickly as possible in an attempt to give it a flight test.

I am using a Mod4 Zlog, so this answers the question as to whether it will work with that version or not. You simply have to solder the connectors on opposite sides of the board in order to match the connectors on the Zlog.

Just follow the directions on eladiomf's web site for setup and you should not have any trouble at all.

My transmitter does not have a dial or slider channel and only has one 3-position switch. I could not figure out a way to get it to work in both automatic and preset modes. This will not be a big problem however. I will simply test it first in automatic mode, and later in preset.

Thanks for the fast shipping eladiomf!

Later;

D.W.

[icebear]

I am using a Mod4 Zlog, so this answers the question as to whether it will work with that version or not. You simply have to solder the connectors on opposite sides of the board in order to match the connectors on the Zlog.

I am using the MOD4 as well - after soldering the connectors I discovered that one should be on the other side... :(

Good luck today DW and looking forward to your results!

/Icebear

[eladiomf]

I am using the MOD4 as well - after soldering the connectors I discovered that one should be on the other side... :(

/Icebear

Thats why I have not soldered the Zlog connectors, so people that have mod3 solder in one side and people that have mod4 solder in the other side.

Connectors are send fix with tape in the mod3 position.

In anyone have mod4, change before solder.

Icebear, sorry for the trouble.

Eladio

[icebear]

No problems Eladio - my mistake! It worked well to de-solder it.

Looks good for a second testflight with the AltHold today!

/icebear

[d_wheel]

Well, the bottom line is it works! Just got in from initial testing with the board and am pleased with the results.

Test setup:

Airplane -------------- Easystar
Motor ---------------- Kontronik Fun 400-36 direct drive brushless
Propeller ------------- APC 5x4.5 electric
Flight battery -------- 4500 mah (2s3p) Kokam (that has seen better days!)
R/C system ----------- Spektrum DX7

With this battery pack, the airplane climbs very slowly and has only 15 minutes duration. Next test will be done with a 3s4p 4400mah Thunder Power pack. It climbs much faster when this is used for power!

The altitude control was connected to the elevator channel. Servo throw was set using a rule of thumb that has served me well over the years. That is, always set your servo throw equal to or less than the amount the surface moves with full trim adjustments.

After launching, I climbed to about 300 feet and activated the system. The airplane went into extremely wild up/down oscillations which almost took it into the ground. I landed and discovered an almost disastrous mistake. I had been bench testing with the sensitivity set to maximum and forgot to turn it down before the first flight! Four test flights were necessary to get a fairly smooth results. I ended up with the sensitivity adjustment about 30 degrees off of the least sensitive end. The airplane would settle into a smooth altitude which varied 15 to 20 feet in straight and level flight. When a turn was made, it would loose 30 or 40 feet and after leveling off would oscillate up and down around the desired altitude for 8 or 10 times and then stabilize again until the next turn was made. By this time, my battery was starting to loose enough power that the plane could not maintain altitude. In this condition, the altitude hold would raise the nose in an attempt to gain altitude. The airplane would stall, loose even more altitude, pick up some speed and zoom up. The stall/zoom exaggerated a little more with each iteration. I disabled the altitude hold and called it a day. Everything considered, I am happy with how it performed.

All testing was done in automatic mode. It should only take one more test flight to get it tweaked in, and it will be time to try preset mode.

Later;

D.W.

[askman]

for the future, in the altitude holding algorythm, it would be great if some form of PID control was implemented. that way, it could be tuned to each airplane via pot or USB.