HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Dec 15, 2011, 10:45 AM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
15,223 Posts
Quote:
Originally Posted by dave1993 View Post
...its hard to believe a unit is sold w/o battery or supercap. imo even 1 minute reaquisition is excessive. anything more than a couple seconds strikes me as problematic in flight. specially with my light weight 1 cent antenna which could take half hour...
There is nothing suspect to sell GPS without battery or supercap, so was remzibi OSD GPS too until this fall, and yes aquisition time was within one minute range, as for any other cold start GPS, because almanac data size download at 9600bps takes 40 seconds.

For me the hard to believe part was that the GPS is an ublox, at this price... I associate this brand with prices more than $50 the chip only !
renatoa is online now Find More Posts by renatoa
Reply With Quote
Sign up now
to remove ads between posts
Old Dec 15, 2011, 11:01 AM
RC beginner
New York
Joined Oct 2008
6,054 Posts
yes, i thought that too. it is the cadillac (or at least lexus) of hobby gps.
dave1993 is offline Find More Posts by dave1993
Reply With Quote
Old Dec 15, 2011, 11:13 AM
Registered User
Austria
Joined Jan 2004
7,999 Posts
Quote:
Originally Posted by dave1993 View Post
while im familiar with the code now it is not actually mine and, yes, it amazes me too.



uses pwm (servo) not ppm in and no timer used because that makes it cpu dependent. serial io is all thats done during the nemea strings then, in the 100ms of so remaining, pwm is read and calculation finished.

i find software uarts far superior to hardware. smaller code, more precision, and of course the ever present polarity issue (max232 is for losers ). also useful for oddball protocols (9 bit etc) that hardware uart cant handle.



you hit the nail on the head. our philosophy was KISS from the start and that was a primary advantage. no funjets or zagis here, only easystar type or $5 scratch foamy. note that like in general aviation piloting throttle is for altitude and elevator is generally fixed or for failsafe only.



fyi most of the "batteries" described in board level product datasheets are actually supercaps. em406 boards go about an hour and my cheapie modules with tiny generic 6v 47mf or 100mf electrolytic go about 5min after fully formed. it would be very interesting to see what retention time is on those frsky units.

are there any closeup photos available?
Sorry for going off topic ...

But

No timer ?
You can't measure the time otherwise ... else ... you need to make a terrible code , that use counter internally ... a big waste of CPU power.
You need a timer, there is not a CPU clock counter

Also between PWM, there is 18mSec only, since normally the TX-RX run at 50hz.

Additionally, in PWM all the 3 signal can come in different time frame, this mean if you actively read PWM in pooling mode you are wasting almost all the CPU power for it.

The only way is interrupt and Timers I don't see how else it can be done.

Anyhow ... here is the picture ... not in perfect focus (focus was only a corner of it) ...

Tchuss

e_lm_70
e_lm_70 is offline Find More Posts by e_lm_70
Reply With Quote
Old Dec 15, 2011, 11:22 AM
Registered User
Austria
Joined Jan 2004
7,999 Posts
Quote:
Originally Posted by RENATOA View Post
There is nothing suspect to sell GPS without battery or supercap, so was remzibi OSD GPS too until this fall, and yes aquisition time was within one minute range, as for any other cold start GPS, because almanac data size download at 9600bps takes 40 seconds.

For me the hard to believe part was that the GPS is an ublox, at this price... I associate this brand with prices more than $50 the chip only !
I did not know that ublox is a luxus GPS chip

I just know Sirf are the cheapest, especially the old chip one ...

Anyhow, reading the specs, ublox is not better then the MediaTek chips (that are also quite chip from the German shop)

Anyhow ... out of the box the FrSky HUB + sensors it just works fine ... all the items from HobbyKings are really good priced ... Hub + display + sensors ... each of them have an amazing low price ...

I'm looking to see the new TX full radio from FrSky ... I can't expect nothing else then extreme low price and good quality , with advanced features ...

Tchuss

e_lm_70

ps: Out of the box, the ublox has USB support ... it would have been cool to have deliver it with mini or micro USB plug .. so it could have had also a 2nd usage ...
e_lm_70 is offline Find More Posts by e_lm_70
Reply With Quote
Old Dec 15, 2011, 12:39 PM
RC beginner
New York
Joined Oct 2008
6,054 Posts
thank you for the photo. sure enough there is no "button" cell/cap. quite surprising to me. nice little unit though and the price is right. kudos to frsky.

Quote:
Originally Posted by e_lm_70 View Post
No timer ?
You can't measure the time otherwise ... else ... you need to make a terrible code , that use counter internally ... a big waste of CPU power.
You need a timer, there is not a CPU clock counter
not true. some, usually the "c girls", consider it easier to depend on non-portable features like interrupts and timers but ive learned to avoid them whenever possible in the interest of portability. rtc is one case where you just cant. timing loops are adequate for most applications and very precise if a little tedious. one drawback is you have to know how microcomputers work.

Quote:
Originally Posted by e_lm_70 View Post
Also between PWM, there is 18mSec only, since normally the TX-RX run at 50hz.
the interval i was talking about before is the 100ms idle period between incoming nmea packets. essential for our autopilot and very tricky at 4800bps which is another requirement for it to work. no auto-baud routines here. that would require DOZENS of additional flash bytes.

there is some (small) argument for using output compare registers for the pwm but even that can be avoided with clever programming.

Quote:
Originally Posted by e_lm_70 View Post
Additionally, in PWM all the 3 signal can come in different time frame
i will mention my/our code only works with consecutive sequential servo pulses which includes all old style rx and most of the new dsp ones. certainly flysky and frsky are ok. we consider using the ppm output available from both mfg to save pins but so far not necessary.

Quote:
Originally Posted by e_lm_70 View Post
this mean if you actively read PWM in pooling mode you are wasting almost all the CPU power for it.
polling is indeed another key to our success.

instead of "wasting almost all the CPU power" i prefer to think of it as "utilizing the cpu to its fullest".
dave1993 is offline Find More Posts by dave1993
Reply With Quote
Old Dec 15, 2011, 03:22 PM
RC Soarer & wheel re-inventer
debianhot's Avatar
Spain, CN, Tacoronte
Joined Jul 2003
400 Posts
flytron 10Hz GPS used with frsky telemetry hub

Successfuly used a flytron 10Hz GPS (the one mounted allready on the pcb and with batery backup for satellite memory) connected to a Frsky telemetry hub instead of the original one . http://www.flytron.com/osd-headtrack...ps-module.html

Can be connected directly as it works with up to 5.5 volts .

Working fine thanks to description of the connection posted by (Jo)Hannes .

One thing that I have noticed is that the Vcc from the hub is UNREGULATED from my 4 cell eneloop rx batery pack (at the time of testing it was 5.23Volts) so no point of using a 5 cell nimh or a 2 cell lifepo4 or lipo or I will fry it .
Trying to opbain a small 3.3 LDO that will make it work with a broader voltage inputs.
debianhot is online now Find More Posts by debianhot
Reply With Quote
Old Dec 16, 2011, 05:39 AM
Per Ardua Ad Astra
Berkie's Avatar
Australia, VIC, Rosebud
Joined Feb 2007
2,236 Posts
Hi all

Can someone please tell me what is the correct status of lights on the D8R-11 when it has been bound properly with the DFT i.e. should the:
red be on solid, off, or flashing
green be on solid, off, or flashing?

The manual is no help at all, and after 3 calls to FrSky - no response at all

Kev
Berkie is offline Find More Posts by Berkie
Reply With Quote
Old Dec 16, 2011, 05:52 AM
Registered User
Austria
Joined Jan 2004
7,999 Posts
Quote:
Originally Posted by Berkie View Post
Hi all

Can someone please tell me what is the correct status of lights on the D8R-11 when it has been bound properly with the DFT i.e. should the:
red be on solid, off, or flashing
green be on solid, off, or flashing?

The manual is no help at all, and after 3 calls to FrSky - no response at all

Kev
My D8R-II has only a red led (maybe green is used for binding or FS)

Solid red -> Is connected
Blinking red -> Not connected
No light -> Off

Tchuss

e_lm_70
e_lm_70 is offline Find More Posts by e_lm_70
Reply With Quote
Old Dec 16, 2011, 06:11 AM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
15,223 Posts
When red is solid, green should flicker, is the data transfer status.
Green starts to blink when no data is receiver for 9ms.
renatoa is online now Find More Posts by renatoa
Reply With Quote
Old Dec 16, 2011, 06:18 AM
Per Ardua Ad Astra
Berkie's Avatar
Australia, VIC, Rosebud
Joined Feb 2007
2,236 Posts
Well, there is my problem, I have a solid red but no green flicker

Does this mean: yes it is bound correctly but it is not receiving data, (because the servos will glitch when connected, but do not work).??

Kev
Berkie is offline Find More Posts by Berkie
Reply With Quote
Old Dec 16, 2011, 06:33 AM
Registered User
Austria
Joined Jan 2004
7,999 Posts
Quote:
Originally Posted by Berkie View Post
Well, there is my problem, I have a solid red but no green flicker

Does this mean: yes it is bound correctly but it is not receiving data, (because the servos will glitch when connected, but do not work).??

Kev
I don't see any green blinking with my D8R-II ... but the HUB is sending data to my TX without problem ... but I'm not using any uplink transmission .. only downlink

Tchuss

e_lm_70

EDIT:

Ups ... actually it is blinking the green ... but is so little blinking that it is almost not visible ... guess is getting few and very short pulses ...
e_lm_70 is offline Find More Posts by e_lm_70
Reply With Quote
Old Dec 16, 2011, 07:14 AM
Per Ardua Ad Astra
Berkie's Avatar
Australia, VIC, Rosebud
Joined Feb 2007
2,236 Posts
During binding the instructions say hold down the FS button on the Tx then switch on the Tx. Then the red light on the Tx should be flashing & the green light "off".

My green light on the TX is not off but on solid, although at the end of the bind process when you switch off the Tx, then back on again, the green light is flashing.

Are these two functions correct?

Kev
Berkie is offline Find More Posts by Berkie
Reply With Quote
Old Dec 16, 2011, 08:32 AM
RC beginner
New York
Joined Oct 2008
6,054 Posts
early on there was an error in the docs. the paper that came with my first unit did not describe the led color correctly. i thought they corrected it though.
dave1993 is offline Find More Posts by dave1993
Reply With Quote
Old Dec 16, 2011, 08:05 PM
Registered User
viper1's Avatar
Melbourne, Australia
Joined May 2006
515 Posts
What is the 2-pin connector for on the FLD-02 ?
And I'm unable to exit the 'Data" screen (Back to the 'Main' Screen) unless I cycle the power, is that right?

Thanks in advance
GJ
viper1 is offline Find More Posts by viper1
Last edited by viper1; Dec 16, 2011 at 11:11 PM.
Reply With Quote
Old Dec 17, 2011, 12:52 AM
Registered User
Romania, Dolj, Craiova
Joined Sep 2007
15,223 Posts
Quote:
Originally Posted by viper1 View Post
What is the 2-pin connector for on the FLD-02 ?
And I'm unable to exit the 'Data" screen (Back to the 'Main' Screen) unless I cycle the power, is that right?

Thanks in advance
GJ
1) software upgrade mode, when connected
2) You are right
renatoa is online now Find More Posts by renatoa
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion FrSky 2.4ghz - Telemetry protocol discussions PLMS Radios 1421 Yesterday 01:39 AM
Discussion FrSky 2.4Ghz - Telemetry PDA application Mybrains Radios 18 Jun 23, 2011 10:02 AM
Sold FrSky Telemetry 2.4Ghz for JR Module, 2 RXs & extra nizee Aircraft - General - Radio Equipment (FS/W) 1 May 07, 2011 03:28 PM
Wanted FrSky 2.4Ghz DIY Kit with Telemetry purcilas Aircraft - General - Radio Equipment (FS/W) 5 May 04, 2011 05:10 PM