Thread Tools
This thread is privately moderated by e_lm_70, who may elect to delete unwanted replies.
Jun 23, 2014, 03:58 AM
Registered User
Thread OP
Mini-HowTo

DIY v2x2 TX module, Ultra Cheap, Ultra Easy


Wltoys v272 - Amazing Hand Launch + Catch & Crash + Fix - With Slow motions (2 min 20 sec)


v272 in Actions ;-)


Hi,

Here is the v2x2 TX module.

Code is based on:
- PhracturedBlue / Deviation -> https://bitbucket.org/PhracturedBlue...1.c?at=default
- Midelic port to Arduino -> https://www.rcgroups.com/forums/show....php?t=2165676
- e_lm_70 hack and port to ATmega48 arduined

Support functions:
- Auto Bind at start up (always)
- Read PPM input (8ch support, 6ch used)
- Send Throttle, Aileron, Pitch and Roll + Flags
- Support Flags: Bind + LED (CH5) + FLIP (CH6)

Needed hardware:
- 5V source (actually anything between 5.5 to 3.3 should do the job)
- (3.6$) I2C to SPI NRF24 adapter -> http://www.ebay.com/itm/NRF24L01-Wir...-/370895866980
- (1.1$) NRF24L01 module -> http://www.ebay.com/itm/High-Quality...-/201060112736
or
- (5.3$) NRF24 PA module -> http://www.ebay.com/itm/NRF24L01-PA-...-/131038716224



Support hardware:
- PPM generator (I use FrSky D4R ... so FrSky TX can be converted in v2x2 RX)
- USBasp programmer
- Jumpers cables

Support software:
- eXtreme Burner -> http://extremeelectronics.co.in/avr-...r-programmers/

Optional hardware (for run the v2x2 RX simulator, for trim the TX, and check functionality ) -> https://github.com/execuc/v202-receiver
- Arduino Nano
- 2nd NRF24
- NRF24 Adapter - > http://www.ebay.com/itm/New-Socket-A...-/261503131763
Last edited by e_lm_70; Jun 30, 2014 at 08:57 AM.
Sign up now
to remove ads between posts
Jun 23, 2014, 03:58 AM
Registered User
Thread OP
Instructions:

PPM goes on SDA pin, if PPM is 12V ... at least a 2.2k resistor is needed, else some magic smoke can happen
Futaba PPM is not supported for now.
Only FrSky PPM is tested, similar code as MultiWii PPM decoder

Two leds (available by default on the I2C to SPI modules)
Start up: RED led off, BLUE ON
While Binding, RED led is off
After binding (sending signal only no feedback), RED led on -> normal TX mode.
Blue LED flash (very fast) with the PPM signal in.
In case of failure at start up of NRF24 ... the RED and BLUE LED blink: RED off + BLUE on <-> RED on + BLUE off

Hex File:

Mandatory Fuse Setting (by default I2C to SPI adapter run at 1MHz)
Low Fuse -> E2 (only this need to be changed)
High Fuse -> DF
Extended Fuse -> FF
Last edited by e_lm_70; Aug 12, 2014 at 02:08 AM.
Jun 23, 2014, 03:59 AM
Registered User
Thread OP
Beta version

This version should read the stick position of Throttle at start up .. and used as default zero
As well ... it read the Pitch control center position .. and it use this middle place for all the other channels.

It is untested ...so .. use at your own "risk"
Last edited by e_lm_70; Sep 11, 2014 at 04:05 AM.
Jun 23, 2014, 05:17 AM
flying beam
blackmoon's Avatar
Tank you .

I bought a V272 for my brother in law, and forgot to buy a rtf (nice move, not getting any younger...), this will come handy, I was thinking going the full house with a multi module on a V911 core9X, but a simpler thing will do quite well.

Could you share the code please ?

I have some At48 and sadsack pcbs that I'll use instead of buying the At48 module from ebay. So I'll need to adapt the code to the pcb layout.
Jun 23, 2014, 05:48 AM
Registered User
Thread OP
Quote:
Originally Posted by blackmoon
Tank you .

I bought a V272 for my brother in law, and forgot to buy a rtf (nice move, not getting any younger...), this will come handy, I was thinking going the full house with a multi module on a V911 core9X, but a simpler thing will do quite well.

Could you share the code please ?

I have some At48 and sadsack pcbs that I'll use instead of buying the At48 module from ebay. So I'll need to adapt the code to the pcb layout.
The code owner is Midelic .. so ask to him in his thread or via PM.

If you don't plan to use the I2C to SPI adapters ... then my solution make no sense ... go for Midelic approach instead.

The beauty of this is to be PNP .. just plug two modules .. reflash firmware ... and fly

No soldering needed, no coding needed .. very simple .. and very reliable.
Jun 23, 2014, 11:18 AM
We can rebuild it!
djdavies83's Avatar
Might pick up these parts next payday, no 3v3 reg needed, it's already on board?
Jun 23, 2014, 01:04 PM
Registered User
hardwiring's Avatar
subbed
Jun 23, 2014, 01:45 PM
Registered User
Thread OP
Quote:
Originally Posted by djdavies83
Might pick up these parts next payday, no 3v3 reg needed, it's already on board?
No 3.3v needed ... the i2c to spi has already

In case you want to build a v2x2 reader, via serail interface, I suggest a arduino nano (with integrated usb) and nrf24 adpater, 1$ for get the 3.3v reg and plug and play
Jun 23, 2014, 02:53 PM
flying beam
blackmoon's Avatar
Quote:
Originally Posted by e_lm_70
The code owner is Midelic .. so ask to him in his thread or via PM.

If you don't plan to use the I2C to SPI adapters ... then my solution make no sense ... go for Midelic approach instead.

The beauty of this is to be PNP .. just plug two modules .. reflash firmware ... and fly

No soldering needed, no coding needed .. very simple .. and very reliable.
Midelic's code is per se "not his", nor the modification you did, is yours... it is based on the GPL code from PhracturedBlue.

GPL being a viral license, you are obliged to share the modification you done to the code if asked to. If not mistaken, PB did advise midelic on the matter, that all code modified from deviation should me made available freely to anyone who asked.

Anyway, I didn't grasp that you used a i2c to spi converter, just read diagonally as always, I was thinking that you merely recompiled the code and made the necessary adjust to have it working on a 48.

I'll ask Midelic, as I see you aren't enthusiastic to share your modifications to the code...
Jun 23, 2014, 03:29 PM
Registered User
Thread OP
Quote:
Originally Posted by blackmoon
Midelic's code is per se "not his", nor the modification you did, is yours... it is based on the GPL code from PhracturedBlue.

GPL being a viral license, you are obliged to share the modification you done to the code if asked to. If not mistaken, PB did advise midelic on the matter, that all code modified from deviation should me made available freely to anyone who asked.

Anyway, I didn't grasp that you used a i2c to spi converter, just read diagonally as always, I was thinking that you merely recompiled the code and made the necessary adjust to have it working on a 48.

I'll ask Midelic, as I see you aren't enthusiastic to share your modifications to the code...
Mainly for your objective the midelic code is more indicated.

If you are not after using the i2c to spi adapter better use a pro mini board, so you have a serial interface for debugging as well. On this atmega48 adapter there is no serial exposed, not the free resources for use it

My code alone is quite useless, since you would need to set up arduino for handle a atmega48 ...

I will open my code later, when I will have the time to clean it a bit
Jun 24, 2014, 01:30 PM
Registered User
@e_lm_70 - you have a github account, if it builds - it's ready. Just put it out, clean up later. Anybody who's spent sometime with code will tell you that there is no such thing as perfect code. Code is always can be cleaned up more if it's longer than 20 lines.
Jun 30, 2014, 08:58 AM
Registered User
Thread OP
Not really fully on topic of the DIY .. but on topic for the Wltoys ...

Here is some actions from my v272 ... hand launch v272 ...

Wltoys v272 - Amazing Hand Launch + Catch & Crash + Fix - With Slow motions (2 min 20 sec)
Aug 05, 2014, 01:22 PM
Registered User
Just tested your module with Turnigy 9x. It works fine. Also works with old Walkera WK-2402 transmitter (needs interchanging of A&E plugs inside since it is not programmable transmitter). I was using 2k7 serial resistor and 1S LiPo as a power supply.

Easiest possible build, you did a great job!
Aug 05, 2014, 01:28 PM
Registered User
Thread OP
Quote:
Originally Posted by estojicm
Just tested your module with Turnigy 9x. It works fine. Also works with old Walkera WK-2402 transmitter (needs interchanging of A&E plugs inside since it is not programmable transmitter). I was using 2k7 serial resistor and 1S LiPo as a power supply.

Easiest possible build, you did a great job!
Thanks for the flowers ... and congratulation for your success

Why 2k7 ?
You mean in serial to the PPM input ?

The i2c module has already a build in 3.3v regulator ... so you can use 1s Lipo directly to the module.

Also ... good to know that works with Turnigy 9x ... I got it work only on my FrSky RX, I still had no time to investigate on make it work on the old but still main TX: Futaba FX-18 .. that has a strange PPM signal
Aug 06, 2014, 12:25 PM
Registered User
Yes,serial to PPM input. The value of this resistor is not critical,just used first at hand. I used 1S lipo as a quick solution, just to test if it works. Voltage regulator on board is probbably not good enough for any lipo voltage, so I'll put regulated 5V eventally.


Quick Reply
Message:
Thread Tools