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Nov 16, 2013, 05:49 AM
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Build Log

((( Ultimate LRS )))


Fly More !

Full project description here : http://www.itluxembourg.lu/site/ultimate-lrs/
Last edited by flipflap; May 17, 2020 at 11:04 AM.
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Nov 20, 2013, 09:37 AM
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Quote:
Originally Posted by flipflap
Hi,

I modified an OrangeRX 1 watt TX to be able to use it on the plane, and have a fully bidirectionnal 1W link for 2 x $28.45

And it works quite well with 232 packets lost on 100.090 (=0.2%)



Detailed description and step-by-step instructions to come...
While waiting for those instructions (), quick questions - using TX as RX, did you break out the channel pins by soldering to the ATMEGA328?
Nov 20, 2013, 11:40 AM
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Thread OP
I'm using just 3 connections : +, - and serial PPM out. For simplicity (and pin accessibility), the PPM out is on the same pin that is used for PPM in on the TX.

Serial PPM is then sent to APM, on which the servos are connected.

So it's very simple : two cables between APM and OLRS
-a cable for serial PPM
-a cable for telemetry data
Nov 20, 2013, 11:50 AM
Registered User
Quote:
Originally Posted by flipflap
I'm using just 3 connections : +, - and serial PPM out. For simplicity (and pin accessibility), the PPM out is on the same pin that is used for PPM in on the TX.

Serial PPM is then sent to APM, on which the servos are connected.

So it's very simple : two cables between APM and OLRS
-a cable for serial PPM
-a cable for telemetry data
Oh yeah - of course the PPMin is a free pin.
So no RX side RSSI to APM?
Nov 20, 2013, 12:55 PM
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Thread OP
I could output it on another accessible pin, for example on the "button" pin.
Nov 21, 2013, 02:47 AM
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shuricus's Avatar
Is it really 1W?

Did you check what is RFM23 power supply?
If it's 3.3V it's too far from 1W.
Nov 21, 2013, 04:02 AM
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Thread OP
Powered at 3.3v it gives 364 mW, powering the module at 5v gives about 600mW.
Nov 21, 2013, 06:47 AM
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shuricus's Avatar
I mean did you check how is it powered in futaba module?
Nov 21, 2013, 01:14 PM
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Thread OP
It's 3.3V
Nov 21, 2013, 01:53 PM
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Quote:
Originally Posted by flipflap
It's 3.3V
Why do the HK Futaba and JR Orange LRS 1W TXes specify that only 3.3v FTDI can be used?
I understand this for the 100mw models, with the RFM22s.
But what part of the 1W models is going to break if you apply 5v? Not the RFM23BP?
Last edited by nicnet; Nov 21, 2013 at 01:53 PM. Reason: clarification
Nov 21, 2013, 02:54 PM
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Thread OP
The RFM23BP needs 3.3V max on its communication pins.
Nov 21, 2013, 03:08 PM
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shuricus's Avatar
It actually works fine with 5V on communication ports in HawkEye.

But HK modules are not 1W as they declare. Much much less!
Nov 21, 2013, 04:08 PM
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Quote:
Originally Posted by flipflap
The RFM23BP needs 3.3V max on its communication pins.
So on the 1W HK modules, is the VCC to RFM23BP also 3.3?
If so, it should be easy enough to cut that track and apply 5v right? (like on your 100mw to 1W conversion?

Acknowledged that 1W in this case is at best 0.5W, likely less ...
Nov 21, 2013, 04:19 PM
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shuricus's Avatar
But you will need another voltage regulator for 5V.
Nov 21, 2013, 04:25 PM
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Quote:
Originally Posted by shuricus
But you will need another voltage regulator for 5V.
True, and also easy.
Nov 22, 2013, 12:15 AM
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Thread OP
Yes it's 3.3V on the "1W" module, and we can also cut a trace and apply 5V via another regulator.

This said the range is already much improved over the 100 mW version, so I didn't need such a modification for now.

Regarding the 3.3V on communication pins, I checked directly with the manufacturer.

Quote:
Dear Benoit,

Thanks for your email.

Would you kindly share more information about your company and the application?
How about the forecast?

May I know when and where you bought the samples from?

RFM23BP is a module combined with RFM23B and power amplifier.
5V power is for amplifier.
So operated power of chip is 3.3V, and the power of the ports which communicate with MCU is also 3.3V.
It means the voltage of the communication pins is 3.3V.

We have many new products with good performance and low price.
Enclosed with the products list for your reference.

Best Regards,
Candy Liu
-------------------------------------------------------------------------------
Hope Microelectronics Co., Ltd.

2/F Building 3, Pingshan Private Enterprise Science & Technology Park,
Nanshan District, Shenzhen 518057, China
Mailbox: [email protected]
Websit: http://www.hoperf.com
Jan 19, 2014, 06:05 PM
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This is fantastic. I hope that instructions and/or firmware available soon. I am looking to minimize radios and would love to get the datalink via the same radio as my flight radio. Thank you for working on this hack.
Jan 19, 2014, 06:51 PM
Flying Wood For Fun
irun4fundotca's Avatar
Quote:
Originally Posted by UAVPILOT1
This is fantastic. I hope that instructions and/or firmware available soon. I am looking to minimize radios and would love to get the datalink via the same radio as my flight radio. Thank you for working on this hack.
software has been available forever now, nothings new really
you just use openlrsng and load the tx as rx for the firmware selection

Chrome based configurator

Openlrsng Thread

Github
Last edited by irun4fundotca; Jan 19, 2014 at 06:58 PM.
Jan 21, 2014, 11:05 PM
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Thread OP
What's new is the support for the 1W HK TX in the plane. openlrsng does not support this configuration.
Jan 21, 2014, 11:09 PM
Flying Wood For Fun
irun4fundotca's Avatar
ahh ok I see, you can do rx as tx but not in reverse
Jan 23, 2014, 01:26 PM
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Thread OP
Exactly, and as the HK 1W TX is very cheap, you can have a full 1W RC + telemetry system for $ 56.
Jan 23, 2014, 01:38 PM
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Quote:
Originally Posted by flipflap
Exactly, and as the HK 1W TX is very cheap, you can have a full 1W RC + telemetry system for $ 56.
So flipflap, when are we going to see your firmware?
Jan 30, 2014, 01:43 AM
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charosenz's Avatar

Why not just flash the TX as an RX in the Gui>


So why would flashing a 1 watt Tx as an RX in the GUI not work like it was simply a 1 watt RX?

Just curious?
Feb 01, 2014, 01:38 AM
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Thread OP
Well it's quite common to do the opposite, flashing a RX as TX. But flashing the 1W HK TX as a RX is not supported by openlrsng, as far as I know :

https://www.rcgroups.com/forums/show...1&postcount=51

In addition I made several changes to have a reliable and fast telemetry link, which fully supports 19200 bauds end to end speed from a 125000 bauds RF link.
Last edited by flipflap; Feb 01, 2014 at 01:49 AM.
Mar 04, 2014, 01:02 PM
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How can you connect a PC to the TX module to feed APM telemetry data to mission planner? Bluetooth would be sweet.
Mar 04, 2014, 02:07 PM
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Thread OP
In my particular setup, I fly from inside the car, so the rain, frost, fog or snow is not an issue. the antenna is on the roof, connected via a 2 meter coax.
Mar 05, 2014, 11:46 AM
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still waiting on my tx from hobbykink. It has been almost thirty days. When they get here I am eager to try this setup. Thank you for the development work on this.
Mar 17, 2014, 12:28 PM
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Quote:
Originally Posted by UAVPILOT1
still waiting on my tx from hobbykink. It has been almost thirty days. When they get here I am eager to try this setup. Thank you for the development work on this.
Don't we need flipflap to give us some firmware to make this work?..

I better order another tx from Hobbyking so I'm ready to go too.
Mar 18, 2014, 03:00 PM
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Thread OP
OK happy to see there's some interest in this project

All instructions and firmware are here
Mar 19, 2014, 12:05 PM
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Quote:
Originally Posted by flipflap
OK happy to see there's some interest in this project

All instructions and firmware are here
Can you please update the pictures for the Tx module connection to APM or pixhawk? Thank you

I finally received my modules in this week and am hoping to play with them this weekend.
Mar 19, 2014, 12:46 PM
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Yes - the only thing that seems to be missing is how to connect the 1W TX (acting as RX) to the APM. Please provide instructions for that, and I'll try it this weekend ...
Mar 19, 2014, 01:55 PM
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Thread OP
OK I'll add a photo of this, basically the PPM serial output will be obtained on the PPM 'in' on the TX. And then the RX/TX pins have to be connected (crossed) to the APM.
Mar 19, 2014, 02:35 PM
Registered User
Ah ok - pretty simple then.
Question - I see both your TX and RX are the Futaba version. Will this work if one of them (e.g. the TX side, so it fits nicely to Taranis) is the JR version?
Mar 19, 2014, 02:37 PM
Registered User
Ok I got it. Then power with five volts and that is it. Perfect
Mar 19, 2014, 02:42 PM
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Beerwiser's Avatar
Have you tried to get telemetry sent to a ardustation at all?
Mar 19, 2014, 02:50 PM
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Thread OP
Quote:
Originally Posted by nicnet
Ah ok - pretty simple then.
Question - I see both your TX and RX are the Futaba version. Will this work if one of them (e.g. the TX side, so it fits nicely to Taranis) is the JR version?
didn't try, but I think there are no other differences than the connector.
Mar 19, 2014, 02:51 PM
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Thread OP
Quote:
Originally Posted by Beerwiser
Have you tried to get telemetry sent to a ardustation at all?
I've flown all year long with APM and mission planner. The firmware I did was really focused on having a reliable telemetry link (100% packets) with smooth servos too.
Mar 19, 2014, 03:57 PM
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Flipflap - what antennas have you been using to get your 4.5km?
We also spoke about getting RSSI out on another pin - could you arrange it? (please?)
Mar 19, 2014, 04:32 PM
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Thread OP
About antennas, everyone has different ideas I'm using a ground plane on a tripod on top of the car :

http://www.gotronic.fr/art-antenne-4...gp433-8506.htm

and the default small antenna provided by HK with the OLRS, on the plane.

Probably I could get very far with a better antenna on the plane, but I appreciate to have a small "unbreakable" and waterproof antenna.

I understand most people will choose a smaller antenna on the car, and a larger one on the plane, but with 1W we can afford bad antennas

The RSSI is implemented, but as there are not many accessible pins on the 1W TX I'll have to post a photo to show where to solder a wire.
Mar 21, 2014, 06:06 AM
Registered User
Flipflap - I tried your firmwares on a pair of 1W TX - RX to one, TX to the other.
But they just beep rapidly, no apparent connection.

Is there a binding process?

it's true that one of my TXes is the JR rather than Futaba model, but I don't think that makes a difference.
Mar 21, 2014, 08:08 AM
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Thread OP
It's mostly based on the original openlrs code, not on the openlrsng.

So basically there's no binding process, it just works out of the box.

Just to explain a bit more the context and why I did this firmware, is because I had issues with the openlrsng, such as
-binding issues
-system failing while in the air
-slow telemetry, and influence on the fluidity of servos
-impossible to use a HK 1W TX as RX, however this would lead to the cheapest 1W RC+telemetry system

It seems that other people are experiencing similar issues, and now the flash memory is pointed as a possible culprit.

As I needed something extremely reliable, I preferred to start from the official flytron code, which beside a small bug on the serial PPM, is working fine since more than 1 year.

In addition I wanted something working perfectly with the APM and telemetry, I mean no packet loss at 19200 bauds, while keeping perfectly smooth servo movements, and be able to fly > 4 km away.

And also I wanted to be able to use the HK 1W TX in the plane to make a 1W bidirectionnal link (which is not a supported configuration with openlrsng).

So I made a firmware doing exactly that and enjoy it since several month. It has less features than openlrsng, and will not receive so much support, but it's simple, reliable (does not rely on flash memory), bidirectionnal 1W and works fine with APM.

Please just notice this is not meant to be an openlrsng replacement for everyone, it's more designed for people who just want to fly far away and reliably with an APM (using serial PPM).

I will only provide limited support and future development, so for most users I would recommend to stay with openlrsng if it suits their needs.

(Well, I however plan to provide a configuration tool and some enhancements if people ask for it )
Last edited by flipflap; Mar 21, 2014 at 08:20 AM.
Mar 21, 2014, 11:01 AM
Flying Wood For Fun
irun4fundotca's Avatar
It's a great project
I have the intention of using it too, once I get the 1w modules ordered
Mar 21, 2014, 05:07 PM
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Thread OP
I've added a wiring diagram for the 1W TX, full instructions are still there.

Last edited by flipflap; Mar 22, 2014 at 03:28 AM.
Mar 21, 2014, 11:55 PM
Registered User
Quote:
Originally Posted by flipflap
I've added a wiring diagram for the 1W TX, full instructions are still there.

I guess I did not realize that the tx was hooked up to the apm as well for programming. Does this mean that the programming is through the apm connection? I thought that the programming might be stand alone in the openlrs and not specific to the apm. Am I mistaken in this? Or is the APM just serving as an pass through of the code so that it goes to both tx and rx at the same time. The reason I ask this is because I was thinking about trying this with a couple of different autopilots. I am using the Arsov pixhawk board and their matrix autopilot. I am also using the MyFlyDream Autopilot. I can switch to just APM if need be but I am just trying to clarify. Thank you again for all the help with this setup.
Mar 22, 2014, 12:03 AM
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Thread OP
To clarify, the programming is done without APM, just by connecting a FTDI cable to the serial port of the OLRS TX.

But actually you had an excellent idea, to use the APM as a programmer for OLRS. But this would need at least to connect another wire to the "DTR/reset" pin, to tell the OLRS when we are programming.
Mar 22, 2014, 01:18 AM
Registered User
Still can't get this to work - despite following the instructions as closely as I can.

I fully understand Flipflaps view that this is unsupported and this sort of support can be a huge investment, so would just like to know if anyone else has got this working, or is also having problems, or is it just me (quite possible).

My symptoms are when applying power to both RX and TX, they just beep constantly and rapidly, no connection being made.
Mar 22, 2014, 03:27 AM
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Thread OP
Hi Nic,

Of course I’ll help as much as I can at least to ensure that several other people can use it (but I don’t plan to support other hardware types for example).

The signification of LEDs is different from original code. As long as you don’t hear the buzzer, it’s connected.

Here's the meaning of the LEDs (it will be more intuitive in a next version) :



I’ve added photos of the setup, be sure to connect the CH2 & 3 together on the APM.

Notice also that the USB cable has to be disconnected from the APM when using telemetry.



Last edited by flipflap; Mar 22, 2014 at 03:54 AM.
Mar 22, 2014, 05:09 AM
Registered User
Hi Flipflap

Both my RX and TX are behaving the same way - blue led flashing, beeping twice a second.
You might even think I've uploaded the TX firmware to the RX, but no - I checked and double checked.

Incidently, it seems that arducopter doesn't have SERIAL3_BAUD, only SERIAL1_BAUD.

I assume you running arduplane? So I could load that firmware onto the APM, but frankly I don't think the serial connection to APM should interfere with radio connection between TX and RX. Or am I wrong?
Mar 22, 2014, 05:53 AM
Registered User
Thank you for clarifying the picture. So it is still the rx it is just the top and bottom view. I thought you were programming both at the same time. This will be perfect.
Mar 22, 2014, 06:16 AM
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Thread OP
Yes it's the same "TX as RX" module seen from top and from bottom. (Notice that the programming is not done through APM, but with a separate FTDI adapter.)
Mar 22, 2014, 06:19 AM
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Thread OP
Quote:
Originally Posted by nicnet
Hi Flipflap

Both my RX and TX are behaving the same way - blue led flashing, beeping twice a second.
You might even think I've uploaded the TX firmware to the RX, but no - I checked and double checked.

Incidently, it seems that arducopter doesn't have SERIAL3_BAUD, only SERIAL1_BAUD.

I assume you running arduplane? So I could load that firmware onto the APM, but frankly I don't think the serial connection to APM should interfere with radio connection between TX and RX. Or am I wrong?
Before trying it with APM, let's try to isolate to find what happens. If you just connect the TX part, without RX, it should light the blue LED and activate the buzzer (continuously).

Two things to investigate :
1) Is the power supply sufficient
2) I wonder if the programming went correctly, can you post a screenshot after programming ?
Mar 22, 2014, 07:29 AM
Registered User
Hi - here is the screenshot.


Immediately after programming it starts to beep twice a second.
Also with other power supplies.
Mar 22, 2014, 09:10 AM
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Thread OP
OK, my mistake, I did upload a wrong version (for 100 mW TX), it should be OK with this.
Last edited by flipflap; Mar 23, 2014 at 05:15 PM.
Mar 22, 2014, 01:13 PM
Registered User
All ok now - many thanks Flipflap. Working perfectly now.
Please- consider my feature request, of rssi out on one of the RX pins, so I can feed it into APM.

Will try some range testing in the next few days.

Thanks again!
Mar 22, 2014, 01:34 PM
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Thread OP
Here's the RSSI pin :

Last edited by flipflap; Mar 23, 2014 at 03:28 AM.
Mar 23, 2014, 12:24 PM
Registered User
Quote:
Originally Posted by flipflap
Here's the RSSI pin :
Hi

I'm getting a voltage off that pin of between 0.015v (no link) and 0.200v (good link).
Is that correct?

Is it true analog rssi, or does it need capacitor/resistor filter like in openlrsng (I assume so).

thanks!
Mar 23, 2014, 05:11 PM
Registered User
Thread OP
Hi,

The RSSI is between 0 and 3.3V, but for very strong RSSI the display was "looping" to a low value, this is now solved. (new release here and as usual instructions here).

You don't need a filter with resistor and capacitor, I'm simply using an analog 100ľA meter with a 33 kilo ohms resistor. (33000 ohms = 3.3 V / 0.0001 A)

Just to be clear for other readers, the RSSI analog output is on the TX.
Mar 24, 2014, 03:02 AM
Registered User
Quote:
Originally Posted by flipflap
Just to be clear for other readers, the RSSI analog output is on the TX.
Ah ok - this is part of the problem then.
I'm looking for RX RSSI, that I can feed into APM (on analogue pin 0). Any chance of this?

thanks!
Mar 24, 2014, 04:24 AM
Multicopter Crash Tester
Amfamora's Avatar
Quote:
Originally Posted by nicnet
Ah ok - this is part of the problem then.
I'm looking for RX RSSI, that I can feed into APM (on analogue pin 0). Any chance of this?

thanks!
Yes it can be done, I got it working yesterday.....

I followed this guide to build the cable http://www.ilovetoflyfpv.com/resourc...2.1_-_rssi.pdf

When configuring in Openlrs chrome configurator force rssi on a port and set it to frsky rssi.

Then in mission planner goto advanced settings and change your rssi channel (I use A08) and change rssi voltage to 3.3v.

Then configure your minimosd after that so it displays accurate readings on the OSD.

https://code.google.com/p/minimosd-extra/wiki/RSSI

*Note to get the OSD reading from the mavlink I soldered a 3 pin header on UART0 (GRD, VCC and TX) instead of using the Y-Cable from the telemetry port. Could not get any values in the OSD until I did this. Something to watch out for.
Mar 24, 2014, 05:10 AM
Registered User
Quote:
Originally Posted by Amfamora
Yes it can be done, I got it working yesterday.....
When configuring in Openlrs chrome configurator force rssi on a port and set it to frsky rssi.
.

Hi Amfarmora

The chrome configurator you refer to is for openlrsng (created by Kha), not openlrs (created by Flytron).

This particular thread you've replied to is about a custom version of openlrs created by flipflap, optmized for use with long distance mavlink telemetry.

You are almost correct, openlrsng has easy setup for rx rssi into APM.
However, flipflap's version of openlrs doesn't (yet) (as far as I can see).
Mar 24, 2014, 05:11 AM
Registered User
Thread OP
Quote:
Originally Posted by nicnet
Ah ok - this is part of the problem then.
I'm looking for RX RSSI, that I can feed into APM (on analogue pin 0). Any chance of this?

thanks!
No problem, I'll output it on the same pin on receiver this evening.
Mar 24, 2014, 06:16 AM
Registered User
Flipflap - how are you measuring TX side RSSI? (I confirm with latest posted version I get 3.3v at close range and 0v with RX off).

I'm measuring this with multimeter - works fine.
Trying with one of those little chinese standalone voltmeters it doesn't work (probably not enough current to drive the leds coming from that pin). So I'm forced to carry my multimeter along with me - not ideal!

I'm using Taranis, and am investigating whether Taranis can do a TX side volt reading feeding into the telemetry screens.

Incidently, on the JR version of the orangeTX, that pin has a pad broken out right next to it - that's convenient!
Mar 24, 2014, 06:59 AM
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Thread OP
I'm using a 100 ľA meter like this one : http://www.selectronic.fr/module-gal...tre-100-a.html
with a 33000 ohms resistor in serie, so 3.3V is full scale.

Can you show the chinese voltmeter you're using ?
Mar 24, 2014, 09:09 AM
Registered User
Quote:
Originally Posted by flipflap
Can you show the chinese voltmeter you're using ?
Something like this:

http://www.buyincoins.com/item/17216.html

But I'm realising, that your RSSI out is not quite what I was expecting.
Can you tell me, what form it takes?
I seem to be getting 3.3v when signal is good, and then it drops to 0v for (what I assume is) every lost packet causing the TX to beep ...

Any ideas how to convert this to smooth analogue voltage?
Mar 24, 2014, 09:49 AM
Registered User
Thread OP
Regarding your voltmeter, it needs a voltage > 4.5V, and 60 mA, it will not work.

"Operating voltage: 4.5 ~ 30V.
Operating Current: <60mA."

Regarding the RSSI, it's a PWM channel, which will give an "analog" voltage, same system as with the normal openlrsng. Try to go further away like several tens of meters and with a house in between to see the needle show a lower value. With an analog meter it works perfectly.

It's not based on lost packets, but really on RSSI. Normally you should't have any lost packet before the RSSI is around 30%.
Mar 24, 2014, 10:22 AM
Registered User
Yeah you're right about that voltmeter - that was stupid of me.

With the openlrsng, I had to put the capacitor resistor filter in to get true analogue - I'll try it here ....
Mar 31, 2014, 02:58 PM
Registered User
Hi
would this work on the 100 mw system also?
All images are now using tx modules. also very suitable to go with a receiver?

any difference between jr or futaba
in the radio, use the ftdi cable to the computer i guess
Mar 31, 2014, 04:54 PM
Registered User
No, it doesn't work as it stands on the 100mw devices. But for those, you can use the "gitsly" branch of openlrsng.

As it stands, this only works on the "1W" TXes (one acting as RX).

No difference between JR or Futaba - I'm running it on both.
FTDI to program, yes.
Mar 31, 2014, 11:16 PM
Registered User
okay what is the difference between 100 mw and 1w system? besides output? mixing units does it make a difference? I run jr radio. Your example is the futaba
Mar 31, 2014, 11:18 PM
Registered User
Thread OP
Exactly, the goal was to support the 'forbidden' configuration of having two 1W TX to create a bidirectionnal 1W link.

Other differences are about the data rate which is allowed.
Apr 01, 2014, 01:08 AM
Registered User
Yes - for some reason openlrsng does not offer a (chrome) configuration of using a 1W TX (readily available from e.g. HK) as an RX.
But it does offer using RX as TX.

The cheap sources of these LRS units (e.g. HK) only provide 1W on the TX side - all the RX units are 100mW. I suppose that soon they will offer 1W RX though - hopefully it will be pin compatible with the 100mW versions (just like the TXes are) so will be supported out of the box by openlrsng configurator.

I remember seeing a 1W RX (was it Hawkeye, DTF UHF????), which is surely already supported by openlrsng out of the box.

But at the moment, as far as I know, flipflap's version of openlrs is the only one available that can have 1W either side on HK hardware (unless you want to replace the RFM22B on a HK RX, which is a bit more involved, but certainly possible), and that is also optimized for mavlink. Gitsly is also optimized for mavlink, but can't use the off the shelf 1W units (I think).
Last edited by nicnet; Apr 01, 2014 at 01:10 AM. Reason: spelling
Apr 01, 2014, 10:09 AM
Registered User
Thread OP
Exactly, you summarize it very clearly, I would add that there is also a way to upgrade a 100mW RX into a 1W system by replacing the radio module :

https://www.rcgroups.com/forums/show....php?t=2033649
Apr 12, 2014, 11:49 AM
Just call me Justin.
This seems great. I was looking for telemetry unit for long range..... And cheap.... But I'm missing the other half of this whole project.

From what it looks like, I can use this to fly my model and get telemetry. But how do I get the data to mission planner? Or is this designed for a TX based telemetry?

My plan is this. Use my cheapo dx6 and use a ppm out Rx and use the ppm out to bridge to the UHF tx module.
Apr 12, 2014, 02:28 PM
Registered User
Thread OP
It's very simple : the TX is connected to the computer with a FTDI cable, to transmit the telemetry to APM.

The cable can be very long if needed, like 20 meters as long as serial data is transmitted over the cable.
Apr 12, 2014, 02:37 PM
Registered User
Hi Flipflap

I've never been able to get range more than 100m or so range with 1W TX as RX. I suppose it must be a problem with RF module. Is there anyway to test precisely whether it's "blown" or not?
Apr 12, 2014, 03:11 PM
Registered User
Thread OP
Well there's a thumb rule : if you think it's blown, it is. And the second rule is always to have a spare module.

Apart from this, the distance can be a good indicator, but if you got only 100 meters with correct antennas (let's say dipoles) then it's very likely blown, or there's a big antenna issue.

I've already had several 1W modules which stopped working for no clear reason (no firmware change, no antenna disconnected etc). I mean normal TX modules, not the hack discussed here. It also happened for 100 mW modules, in some case they stop working, in other cases their power is strongly reduced.

I've got a spectrum analyzer so it's easy to check the power transmitted, but without such equipment or a SWR meter it's not so easy.

Did you try with the standard OpenLRS firmware (not kha's) ?
Apr 13, 2014, 11:07 AM
Just call me Justin.
Quote:
Originally Posted by flipflap
It's very simple : the TX is connected to the computer with a FTDI cable, to transmit the telemetry to APM.

The cable can be very long if needed, like 20 meters as long as serial data is transmitted over the cable.
Is there a how-to on that side of this project....
May 02, 2014, 05:31 AM
Registered User
Very nice work !

Your distance of 4.5 km is made with 3.3v or 5v power ?
What kind of antenna do you use ?

How many hopping channels do you use ?
is that the "RF DEVICE ID HEADERS" are generated randomly ?
to be able to use the system with several people.
May 04, 2014, 12:15 AM
Registered User
Thread OP
The 4.5 km is made with 3.3V, stock antenna on plane, and this antenna on the TX (on a tripod) :

http://www.gotronic.fr/art-antenne-4...gp433-8506.htm

I started from the original OpenLRS code, so it's just 3 hardcoded channels.
May 04, 2014, 07:36 AM
Registered User
charosenz's Avatar

Rssi at distance??


Quote:
Originally Posted by flipflap
The 4.5 km is made with 3.3V, stock antenna on plane, and this antenna on the TX (on a tripod) :

http://www.gotronic.fr/art-antenne-4...gp433-8506.htm

I started from the original OpenLRS code, so it's just 3 hardcoded channels.
Hey guys, I am new to LRS.....I am using a 9xr with the Hawkeye 1watt Tx and a 100mw orange Rx. I start out with a RSSI at about 100+ and it drops to about 70 when I get about 200 feet away. How far will you let your rssi drop before you get concerned about loosing control? I would appreciate hearing some real world numbers.

Thanks.
May 04, 2014, 11:08 AM
Registered User
Thread OP
Well, this is a question for the OpenLRSng thread, as in this thread I'm using a custom firmware. On this firmware, it's about 30% RSSI.

You'll notice there's a rather clear limit where you pass from all packets good to almost all packets bad
May 04, 2014, 01:04 PM
Registered User
Quote:
Originally Posted by flipflap
The 4.5 km is made with 3.3V, stock antenna on plane, and this antenna on the TX (on a tripod) :

http://www.gotronic.fr/art-antenne-4...gp433-8506.htm

I started from the original OpenLRS code, so it's just 3 hardcoded channels.
Thinking of getting one of those - does it come with SMA connector on the 2.5 coax?

Flipflap - how about uploading version with RX RSSI - please?
May 04, 2014, 04:57 PM
Registered User
charosenz's Avatar
Quote:
Originally Posted by flipflap
Well, this is a question for the OpenLRSng thread, as in this thread I'm using a custom firmware. On this firmware, it's about 30% RSSI.

You'll notice there's a rather clear limit where you pass from all packets good to almost all packets bad
Thanks. I post it over there too.
May 04, 2014, 11:50 PM
Registered User
Thread OP
Quote:
Originally Posted by nicnet
Thinking of getting one of those - does it come with SMA connector on the 2.5 coax?

Flipflap - how about uploading version with RX RSSI - please?
It comes with a BNC connector, you'll need a small BNC-SMA adaptor.

And I don't forget the RX RSSI
May 05, 2014, 12:45 AM
Registered User
Quote:
Originally Posted by flipflap
It comes with a BNC connector, you'll need a small BNC-SMA adaptor.
I suppose it comes with BNC male?
So I need to get BNC female to SMA male adaptor.
Like this:
http://www.ebay.co.uk/itm/SMA-Male-P...item3a70f9ece4
?
May 05, 2014, 08:39 AM
Registered User
Thread OP
Good question, on mine I cut the connector and soldered another one, I don't remember if the default connector was male or female.

Started playing with thermals this week-end, with the APM FBWA mode, and a switch on the transmitter to turn in circles with a precise roll angle (about 25° works fine for my EG).
It's then very easy to thermal, and I made a number of climbs from 200 to 1000 meters just by turning the switch on and off (straight flight / circle).
Even if the plane starts to exit the thermal, if a few switch flips it gets back into thermal.

With the plane exactly above the antenna (worst case), it takes about 700 meters altitude to loose packets, but as soon as the plane is a bit out of the dead zone it comes back to 100% packets.
May 05, 2014, 09:43 AM
Registered User
charosenz's Avatar
Quote:
Originally Posted by flipflap
Well, this is a question for the OpenLRSng thread, as in this thread I'm using a custom firmware. On this firmware, it's about 30% RSSI.

You'll notice there's a rather clear limit where you pass from all packets good to almost all packets bad
Flip,

What method are you using to determine the number of good vs bad packets, Leep?
May 05, 2014, 10:35 AM
Registered User
Thread OP
I'm referring to the small 'link quality' popup in Mission Planner.
May 08, 2014, 11:47 AM
Registered User
Hi Flipflap

Problem.
Received my Pixhawk this week (RTFhawk variant), and PPM from the 1W with your firmware does not get recognized by it.
Exactly the same config but with openlrsng works fine.
Exactly the same config but with APM instead of Pixhawk works fine.

Any ideas?

Any update on the RX RSSI?
May 08, 2014, 11:06 PM
Registered User
Thread OP
I've got an idea, it's about the low pulse duration in the serial PPM. This duration in itself is not important, as the servo value is represented by the time between two pulses.

But it's possible that Pixhawk needs a larger pulse. Actually it's very likely, as with the default OpenLRS, the pulse was too short for APM, so I widened it until it was recognized by APM.
May 16, 2014, 04:20 AM
Registered User
2flipflap: what channel frequences are used in your firmware? don't you want to share your code changes? thanks
May 17, 2014, 01:24 PM
Registered User
Thread OP
It's just arbitrary frequencies, I'll have to check the exact channels.

The code is already strongly modified, but I keep it closed source as I plan to do something PIC based.

There are small PICs which support natively USB, don't need a crystal, and cost a few bucks.
May 20, 2014, 05:00 AM
Registered User
This is what I've found in OpenLRS sources:

...
unsigned long CARRIER_FREQUENCY = 435000; // 435Mhz startup frequency
unsigned char HOPPING_STEP_SIZE = 6;// 60kHz hopping steps

#define FREQUENCY_HOPPING 1 // 1 = Enabled 0 = Disabled
//###### HOPPING CHANNELS #######
//Select the hopping channels between 0-255
// Default values are 13,54 and 23 for all transmitters and receivers, you should change it before your first flight for safety.
//Frequency = CARRIER_FREQUENCY + (StepSize(60khz)* Channel_Number)
static unsigned char hop_list[3] = {13,54,23};
...


is it possible that you make special build for me with frequencies, that are legal in my country (so they are in band 433.050 - 434.790 MHz)?
May 20, 2014, 02:47 PM
Registered User
Thread OP
no problem, I selected my frequencies to be out of the gopro (1) frequencies.
May 20, 2014, 03:16 PM
Registered User
that would be cool - thank you
May 20, 2014, 06:29 PM
Registered User
Hello Flipflap,
What about failsafe ?
Is it possible to disable it, to let APM manage the plane (Return to home, ...) ?
Thanks.
May 20, 2014, 07:55 PM
Registered User
Thread OP
On my setup there's a three way switch : manual / FBWA / RTL.

I take care to set up the failsafe (by clicking the OLRS button) when the switch is in RTL mode. In this way the APM goes in RTL anytime the failsafe kicks in.
May 20, 2014, 10:50 PM
Registered User
Quote:
Originally Posted by flipflap
no problem, I selected my frequencies to be out of the gopro (1) frequencies.
Hi flipflap

If you are uploading a new version, please also upload version with:

-rx side RSSI (to connect to APM)
-updated PPM compatible with PIXHAWK

Many thanks!
May 21, 2014, 03:28 AM
Registered User
Quote:
Originally Posted by flipflap
On my setup there's a three way switch : manual / FBWA / RTL.

I take care to set up the failsafe (by clicking the OLRS button) when the switch is in RTL mode. In this way the APM goes in RTL anytime the failsafe kicks in.
Ok, but what's happened when you have a hardware failure (antenna problem, TX switched off, RFM died, ...) ?

On my previous setup, when there is no link, there is no PPM out.
Then, the APM enter in failsafe mode (RTL).
May 21, 2014, 04:11 AM
Registered User
Quote:
Originally Posted by Synthex
Ok, but what's happened when you have a hardware failure (antenna problem, TX switched off, RFM died, ...) ...
Then the receiver should go to failsafe mode and send preset safe values for each channel (RTL on mode channel), shouldn't it?


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