Help with Frsky Lite as TTL converter

Arion · Post by **Arion** » Fri Dec 30, 2011 7:58 am

Hello all. I am new to this forum so I hope I am posting in the right category. I just want to make sure of something before I install the frsky lite into my turnigy 9x. I have the er9x FRSKY firmware loaded into my radio. I am going to use the frsky Lite as the TTL converter. I have studied the picture at http://code.google.com/p/er9x/wiki/FRSkyLiteTTL . I am almost certain that the four small pins (on the upper side of the frsky lite in the diagram) go to the frsky telemetry module and the larger pins on the lower side go to the MISO, MOSI and ground pins on the turnigy 9x atmega64 chip. Is this correct? I have the frsky DHT DIY mod in my turnigy. I have used the frsky usb cable to connect the DHT module before and all works well. I am hoping to get this telemetry data with the er9x firmware. Thank you very much for your time.

Arion

Post by **Rob Thomson** » Fri Dec 30, 2011 9:43 am

Does this help?

Actually... it is the same picture!

Post by **Rob Thomson** » Fri Dec 30, 2011 9:48 am

The VCC side of the board gets attached to the main board.

So by the look of it; the servo connector side goes to the frsky module.

I have deduced this by looking at step 3 on this doc:

http://er9x.googlecode.com/svn/trunk/do ... emetry.pdf

Different ttl convertor - but essentially the same thing!

Rob

wilco1967 · Post by **wilco1967** » Fri Dec 30, 2011 1:44 pm

I did (nearly) the same modification yesterday, with a generic 232 converter off ebay, but it shouldessentially be the same with the FRSky lite.
This is the converter I used
http://www.ebay.nl/itm/280731969278?ssP ... 2990wt_952

The picture you show,

is for the modification using a DJT module. see also http://code.google.com/p/er9x/wiki/HardwareGuides telemetry mods for the schematic (this is for a DJT)..
For a FrSky DHT the connections are slightly different.

From the picture in your post:
- the pink wire from the top of the FRsky lite, marked 'RxD' in the drawing (but actually TxD / T1IN on the MAX3232 IC), should go to the RxD the DHT module (4th pin of the DHT serial port connector) (so don't connect to the 9X board, as shown in the picture, but straight to the DHT module's RxD pin)
- the black (?) wire, on the 2nd pin of the FRsky lite top row, marked 'TxD' in the drawing (but actually RxD / R1OUTon the MAX3232), should go to the TxD of the DHT module (3rd pin of the DHT serial port connector).
These are the only 2 wires that go to the DHT for the serial connection. No need to connect GND

DHT serial port pin layout = GND, +5V, TxD, RxD. Starting from bottom, (with serial port facing to the right, other cables top)

- the brown wire in the picture, on the 4th pin of the FRsky lite top row = Vcc, should go to the most left pin on the 9X back board as shown in the picture. This is +5V from the 9X.
- the other black wire, on the 1st pin of the FRSky lite top row = GND, should go the the most right pin on the 9X board as shown in the picture

- the green wire, at the bottom of the Frsky lite, on the 'USBO' plug, marked RxD (but actually R1IN on the MAX3232), comes from CPU MISO (pin 3 of the CPU) = data from 9X to DHT
- the gray/black wire, at the bottom of the Frsky lite, = TxD (actually T1OUT), should go through a 470 ohm resistor (or similar), and then go to CPU MOSI (pin 2 of the CPU) = data from DHT to 9X. The resistor is to allow programming of the 9X (with eePe) with the DHT still connected.
- the brown and white wires are not used....

Hope I got it right..... Can someone please check who actually has the Frsky lite mod.

Arion · Post by **Arion** » Sat Dec 31, 2011 2:19 am

Thanks for all the help everyone. I finally got it to work. It did not work on my first try. I had to swap the Tx and Rx from the Frsky DHT. I used my o'scope to find which pin on the FrSky DHT was actually outputting the PPM signal. I drew a wiring diagram for anyone else who needs the reference. I tested it and it works great. Here is a link to a YouTube video of it in action ( http://youtu.be/OYKhn7W3rCg ). The first part of the video is the only relevant video.

*The small pins of the FrSky Lite are represented on the left side of the FrSky Lite in the diagram.

wilco1967 · Post by **wilco1967** » Sat Dec 31, 2011 1:22 pm

Arion wrote:Thanks for all the help everyone. I finally got it to work. It did not work on my first try. I had to swap the Tx and Rx from the Frsky DHT. I used my o'scope to find which pin on the FrSky DHT was actually outputting the PPM signal. I drew a wiring diagram for anyone else who needs the reference. I tested it and it works great. Here is a link to a YouTube video of it in action ( http://youtu.be/OYKhn7W3rCg ). The first part of the video is the only relevant video.

*The small pins of the FrSky Lite are represented on the left side of the FrSky Lite in the diagram.

Good to hear you got it working !

I see you did not add a resistor in the line to ATMega pin 2 ?
Can you still upload / download the code using eePe with the DHT connected (and possibly receiving data from a powered-up receiver) ?
I haven't tried without the resistor. In fact.... I haven't tried to do any eePe upload with a 2way receiver sending back data at the same time.... only with the DHT connected, but no receiver active

Arion · Post by **Arion** » Mon Jan 02, 2012 6:48 am

To be honest I am new to the er9x firmware. I have not researched a good reason to be able to want to program the radio with it powered on. What are the benefits? I already have the er9x firmware flashed on the radio. I read that I can use the eepe software to load model data to the radio. I think I can do that with the radio power switch off though. I will have to check and see if the 5v supply from the programmer(Arduino Uno in my case) supplies power to the transmitter and frsky lite module. If not, then I do not see a personal need to add the resistors. Maybe you have some additional info? I would like to know more. Thanks for bringing the resistor issue up.

Arion

Post by **jhsa** » Mon Jan 02, 2012 8:05 am

Arion wrote:To be honest I am new to the er9x firmware. I have not researched a good reason to be able to want to program the radio with it powered on. What are the benefits? I already have the er9x firmware flashed on the radio. I read that I can use the eepe software to load model data to the radio. I think I can do that with the radio power switch off though. I will have to check and see if the 5v supply from the programmer(Arduino Uno in my case) supplies power to the transmitter and frsky lite module. If not, then I do not see a personal need to add the resistors. Maybe you have some additional info? I would like to know more. Thanks for bringing the resistor issue up.

Arion

Hi, please have a look here. this mod doesn't use the frsky lite but explains about the resistors.. I hope it's helpful for you..

er9x.googlecode.com/svn/trunk/doc/TelemetryMods.pdf

JEANALTAYR · Post by **JEANALTAYR** » Mon Jan 02, 2012 5:12 pm

Hi, please have a look here to.
http://www.rcgroups.com/forums/showpost ... ount=13119

chrispaiva · Post by **chrispaiva** » Mon Feb 13, 2012 8:15 am

Is there any reason to get power (+5V and GND) from TX9 Back Board instead of the DHT ?

ekill · Post by **ekill** » Sat Feb 25, 2012 9:29 pm

I was hoping someone could review this diagram for accuracy. Still unsure ifFrsky Lite be powered from DHT? Or does it have to be powered from 9x?

Thanks,

Earl K.

MichelvdD · Post by **MichelvdD** » Mon Mar 19, 2012 2:07 pm

I did this mod yesterday and it works like a charm!
You wil have to power de FrSky Lite from the 9X, put gnd en 5+ to the small pins of the FrSky Lite. Thats the only thing missing in your drawing.

gbirkus · Post by **gbirkus** » Mon Mar 19, 2012 9:00 pm

somebody experienced issues with powering up the transmitter with this mod?

Post by **Rob Thomson** » Mon Mar 19, 2012 9:03 pm

That image should be added to the wiki

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marcioh · Post by **marcioh** » Tue Mar 20, 2012 12:36 am

gbirkus wrote:somebody experienced issues with powering up the transmitter with this mod?

I was using for more than 1 year the transistor based converter did by myself , without issues.
Last week I replaced it with the frsky lite just to have a cleaner mod.
Did also the sound mod.
Now the transmitter have powering up issues. Sometimes doesn´t start , blank screen, nothing.

Post by **jhsa** » Tue Mar 20, 2012 1:26 am

I have the frsky upgrade lite as the level converter and din't have a problem yet.. I hope it keeps like this..
One thing I did was add the resistors as in Mike's mod..

gbirkus · Post by **gbirkus** » Tue Mar 20, 2012 7:45 am

marcioh wrote:
gbirkus wrote:somebody experienced issues with powering up the transmitter with this mod?
I was using for more than 1 year the transistor based converter did by myself , without issues.
Last week I replaced it with the frsky lite just to have a cleaner mod.
Did also the sound mod.
Now the transmitter have powering up issues. Sometimes doesn´t start , blank screen, nothing.

this is what I asking for.
T9x is with blank screen sometimes.
I have 470ohm resistor between Pin2 and frskylite (green line in picture).
But the issue also remain when frskyLite is only on +5V and GND. (RX/TX not connected)
There is some issue with VCC or current while switching on the T9x.
any ideas, please?

Post by **GrootWitbaas** » Tue Mar 20, 2012 2:16 pm

What 5v supply you tap? Use the one on the switch board, not the main board, i'm guessing you run from the main board and overloading the 5v line

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marcioh · Post by **marcioh** » Tue Mar 20, 2012 3:04 pm

one more issue to the list...
today I tried to flash my transmitter with open9x , after more than 1 year using er9x.
for my surprise got errors in both eepe and companion... the transmitter was dead.
tried to disconnect the frsky module completely from the radio. no sucess.
then opeened the radio and cut the miso and mosi lines that go to the frsky lite. then the programming was sucessfully.
what a hassle.
my mod does not include any resistor. could this cause the problem?

Post by **GrootWitbaas** » Thu Mar 22, 2012 1:10 am

Yes it could, maybe add 1k in the Miso and Mosi lines, test and see if it helps. May need to go up to 10k but I think 1K should do the trick.

newmi · Post by **newmi** » Mon Mar 26, 2012 1:34 pm

Hello,
I want to try this mod, but i have a doubt. Are ther any problem to take 5V, Gnd from DJT module?
In other transmitter i used a max232 board and took 5v and Gnd from DHT (internal module) and worsk fine.

thanks

Post by **Rob Thomson** » Mon Mar 26, 2012 3:10 pm

Should be ok.. I if you trace the leads I believe the come from the same 'power tracks'

newmi · Post by **newmi** » Tue Mar 27, 2012 12:43 pm

Rob Thomson wrote:Should be ok.. I if you trace the leads I believe the come from the same 'power tracks'

Thanks. This mod works fine with DJT module and Take +5v,GNd from módule.

regards

GTiDon · Post by **GTiDon** » Wed Mar 28, 2012 6:29 am

Thanks this thread finally closed the loop in the circuit for me which I could not find anywhere else

I too have the Blank Screen half the time on start up, has there been a solid solution found for this?

Post by **GrootWitbaas** » Wed Mar 28, 2012 5:49 pm

As suggested elsewhere also, See if you can "tap" your 5v from the Buzzer/switch board, Not from the main board. You may be overloading your main board 5v regulator. That regulator is rated only 100ma ...and the one on the switch board is also 100ma but it's not used.

GTiDon · Post by **GTiDon** » Wed Mar 28, 2012 8:18 pm

GrootWitbaas wrote:As suggested elsewhere also, See if you can "tap" your 5v from the Buzzer/switch board, Not from the main board. You may be overloading your main board 5v regulator. That regulator is rated only 100ma ...and the one on the switch board is also 100ma but it's not used.

Where are you from GrootWitbaas?

I have tried this, still no success, I have created a new thread dedicated for this problem because it does not seem to be resolved.
Here
viewtopic.php?f=23&t=580

Post by **GrootWitbaas** » Wed Mar 28, 2012 11:22 pm

I'm from SA originally, but live in Germany.
I think you have been answered in the other thread. I was not sure if maybe the regulator got overloaded. if it does then you have the same type of symtoms, but seems it is not the problem in this case.

Post by **Rob Thomson** » Thu Mar 29, 2012 5:57 am

If you look at the speaker mod diagrams on the wiki - it shows where you can tap a stable 5v from

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txwindrider · Post by **txwindrider** » Fri May 11, 2012 10:50 pm

Today I made the Frsky Lite mod to my 9x with DHT. The info on this thread was invaluable. Kudos to all who've put in the effort on this.

As a relative noob, I thought it would be worth sharing some of my lessons. I followed ekill's pic mostly, with the Vcc and GND connections to the Frsky Lite made according to the pic for the DJT mod on the wiki. It took a little figuring to connect the dots from the different pics, but it worked perfectly right from the beginning (again, kudos to those who've posted these pics). I've turned my tx on and off many times but haven't seen the blank screen issue mentioned by others. The only resistors I used are the 2 x 220 ohm shown on ekill's pic.

It's been many years since I've done serious soldering on PCBs, and never with SMDs. I'm not ashamed to say I was freaked out while soldering the fine wire connections to the main board. Using wire from an ATA ribbon cable, tinning it, and using a fine tip on the soldering iron got it done. I'm not sure I'd recommend it to just anybody though.

This was (hopefully) the last of my 9x hardware mods. My others:
- usbasp interface with connections to main board, wired to a mini usb connector hidden in the battery compartment
- DHT led and switches on panel of now empty 9x rf module. Replaced DHT toggle switch with small slide switch to keep switch from touching surfaces while laid down.
- Hobbyking backlight
- Life battery

I have a pic of the inside of my tx with all mods completed if anyone would like.

Based on my experience I'd suggest two things to help noobs like me:
- Post one complete pic showing everything required. Ekill's would be perfect if it showed where the power connections go.
- Make it easier to find instructions for the telemetry features of the er9x-frsky firmware. (If they exist I'm not finding them.)

Thanks again all.

Jimmckeown · Post by **Jimmckeown** » Mon May 14, 2012 4:44 am

MichelvdD wrote:I did this mod yesterday and it works like a charm!
You wil have to power de FrSky Lite from the 9X, put gnd en 5+ to the small pins of the FrSky Lite. Thats the only thing missing in your drawing.

I would like to get some help to repair damage to my TX will attempting to solder the GND from the small pin on the ffd_lite to the 12th pin in on the left side at the bottom of the TGY 9x board (the one under the DHT pcb.) The result was smoke that appeared from near the main switch. I have carefully gone over main board and front board looking for burn marks, there is trace difference in the surface of the rear (back) board near the 5 pin soldering points near close to where the battery connects. The reason this happened was because I had the battery in and switch off. I think I should have removed the battery. Now in your estimation can this repaired. Will the damage likely extend to the main board. For future reference where on the DHT board is the a source of energy that does not come directly from the ER9x.
I`m running the first version of gruvin`s ER9x with osd. I have the FrSky DHT, D8R-II, Hub, sensors etc. Any partial advice would be very much appreciated.

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