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Old Apr 08, 2012, 04:38 AM
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@Timecop: Good idea! The skyartec RX lacks of ppm output, so it would be cool to use the frsky instead!

@Bracame: I really have problems to understand how the channel sync is made between the TX and RX (after you have pushed the bind button on the RX).
I may have missed something with connections between the STM8S and the cc2500, because I guess GD02 should be connected somewhere.
Would it be possible to checks the pins on your side?

cc2500 board connections, from left to right
1 R28 -> PA4 (not really connected, missing resistor?)
2 R29 -> not connected ?
3 R30 -> PA5 (CSn)
4 R31 -> PA6 (GDO0 / ATEST)
5 GND
6 R32 -> not connected ?
7 R33 -> PC7 (SPI_MISO)
8 R34 -> PC5 (SPI_SCK)
9 R 35 -> PC6 (SPI_MOSI)
10 C24 -> VCC
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Old Apr 09, 2012, 03:46 AM
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I surrender: I've spent too much time trying to understand how the rx bind works, and I've obviously broke something, because now my tx/rx doesn't even bind with the original skyartec firmware... When I'll some time, I'll probably desolder the cc2500 module to replace it with a corona diy kit...
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Old Apr 09, 2012, 12:39 PM
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Sorry for the delay and for your cc2500 if it is dead (try to reset all possible think , another code here http://www.rhydolabz.com/documents/w...ample_code.zip)


For the connection, you'r wright. Some better photos :
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Old Apr 09, 2012, 12:55 PM
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... And does your sky705 seem to work ok with skyartec software via usb ?
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Old Apr 10, 2012, 03:30 AM
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According to me the stm8 mcu is a good choice, but the conception of the sky705 is really bad. For example, they don't use the SPI or UART peripherals and bitbang everything! Why a ch372 instead of something like cp2102? The uart2 pins are wired to .... an unused pad.

So I didn't even bother trying to "resurrect" the cc2500. I removed it - and the ch372 - and now I've a lot of free IO
I'll probably implement a ppm encoder and add a 2.4ghz rf module (frsky, corono or a fs-hf030).

I'm sorry not being able to help you. Using the cc2500 itself is easy, the main issue you'll have is to understand the proprietary method used to bind the rx with the tx. It doesn't seem to be documented in the specs or in any lib I've seen.
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Old Apr 10, 2012, 08:07 AM
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ch372 = Cheap chinese USB chip. Probably 1/10th the price of CP2102
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Old Apr 10, 2012, 01:02 PM
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Without a specialiste like Sbaron, this post is dead. I've learn c library of stm8 , watching the asm code, trying playing with ida in st7 mode , etc .....

As we says in France : I'm swimming into a big smog !! (not andertand all)

Since I've my discovery, the second solution is possible. Xavier give me he's code and I'm trying to modify it as my mind ....

Skyartec win this battle but I espect not the war !

Thanks a lot to you
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Old Apr 10, 2012, 01:23 PM
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It's not totally lost. I can't help for cc2500 support but even without this, the TX itself has a good potential.

Replace the rf module by something like this: http://www.hobbyking.com/hobbyking/s...Y_Module_.html

and you'll have a very cool tx.

If you're interested, I still can provide some code for inputs, ppm output, led and uart
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Old Apr 10, 2012, 01:34 PM
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Thanks !

Of course i'm interested and i think a lot of people ho have this anti freedom tx !

If anyone is intersted, say in your opinion !! Skyartec : the best tx at +60 S !!!!!

(prefer turnigy !!! for the price)
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Old Apr 12, 2012, 07:10 AM
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Here is Xavier's source (provide without any warranty )
I'll modify it for 6 channels and setting parametres with a 16X2 lcd.
If possible, fms ppm with uart on a rs232 output.

http://sites.google.com/site/stm8sdi...-2-4ghz-module
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Old Apr 12, 2012, 12:28 PM
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Here are some sources that could help coding something for this remote.
There is still a lot to do before having something usable...
As my remote control is seriously altered, I can't help more.
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Old Apr 14, 2012, 07:24 PM
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Thank you Sbaron, I've a question ....
If i boot the cc2500 with the original board (configuration ...) and after switch to mine, does the cc will accept ?
I'm working on my discovery board, Xavier'sources are a lot modified.
And i'm waiting for that : http://cgi.ebay.fr/ws/eBayISAPI.dll?...84.m1497.l2649
For easy setting of the tx.

Last question : a buddycode for corona diy ??? ;-)
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Old Apr 16, 2012, 09:44 AM
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The previously attached code already configure the cc2500 exactly as the original firmware. What's missing is the code to find the address and the channel used by the receiver, and then store it into the structure rx_config. Without reversing the original firmware with a debugger or a disassembler, I doubt that you can transmit something.

Regarding the corona, it would be easy to add support since it needs only ppm input. See: http://www.mftech.de/ppm_en.htm
You have to configure a timer to generate an interruption every 22.5ms , something like that :

Code:
TIM3_DeInit();    
// ( 1 / ( 16Mhz / 64 ) ) * ( 5624 + 1 ) = 22500us
TIM3_TimeBaseInit(TIM3_PRESCALER_64, 5624);
TIM3_ITConfig(TIM3_IT_UPDATE, ENABLE);
TIM3_Cmd(ENABLE);
And then in the interrupt handler, generate the signal using GPIO_WriteLow / GPIO_WriteHigh / delay_us. The PA4 pin, wired but not used, would be usable for this.

I've just managed to get a th9x rc, so I'm not very motivated to continue with this for now...
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Old Jun 11, 2012, 07:49 PM
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Finishing

Hi,
C learned :

I'm finishing my new TX with the discorery board. (whith a 16X2 LCD and corona diy module)
- 6 input proportional (2 stick and 2 pots)
-2 input with 3 positions switch
-1 switch for engine stop
-1 switch for dual rate
-1 switch for changing phase
-1 switch for ?? (i wonder what to do with)
-1 little push button for dynamic trim (setting actual position to neutral position)
-1 jack ppm output for usb simulator
- 1 little switch for unpowering the corona when i simulate
-4 microswitch for sttings
- 8 ouput (corona)

software settings (with lcd):

pots calibration
DR (percent)
expo (negative & positive gain -99 to 99)
16 mixer input-ouput-gain+&gain- (will increase to 20 if needed)
Min,neutral,max for output
power of motor for timer in proportional mode
beep/nobeep
etc ..
memory (in flash) : 4 model with 2 phases
Stm8 is powerfull !! but have little flash ..

Will send pictures when availables ...

Thank you again for your help
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Old Aug 07, 2012, 07:34 PM
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The post !! (in french)

http://www.modelisme.com/forum/aero-...ce-maison.html
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