Help: Flashing MCPX, really broken 3 in 1 wanted.

[coredump]

I want to download some custom firmware into the MCPX
3 in 1, which means, write your own FBL control to have
adjustable tail gain etc.

I have make enough progress understanding how to talk
to the receiver chip. See here:

https://www.helifreak.com/showthread.php?t=427772

I also make a PDI plug to download the firmware into the
atxmega16a4 on the 3 in 1. I can read the device fuse and
lock bits fine. I believe I just need to click "erase device"
and then I will be able to down my own firmware to the 3 in 1.
The catch is that, I will never able to get the original firmware
back.

But it seems such a waste to destory a perfectly working
3 in 1. Here is where I am asking for help.

Does any one has some really broken 3 in 1 board they
don't want so I can buy it cheap? I do mean really broken.
Things like board do not bind is fine by me because I can still
use the MCU to do some programing with the gyro etc.
I can even pull the receiver signal from the good board.

I also perfer the V2 board because V1 board are good for
BL conversion, even broken one has some value to some
of us. If you have a really broken V1 board, I might able to
fix it up for you.

Note: Burning FETs are easy fixable by a few members here.

PM me if you have some broken 3 in 1.

Thanks

[decompyler]

I can't wait to see your results! I was going to start adding a pot to my board to adjust the tail gain but, I think I may wait to see what you come up with here. Good luck and godspeed man!

[4712]

Sorry to say, I had not a single board, which I could not repair. ... and I have seen a lot of awful tortured poor pieces, where the souls was burned out...

So, May be someone sends You one of these and You make it a hero...

[coredump]

Yah, pretty much same here. I have repair some really broken boards too.
All but one of the V1 boards. The receiver can receive data, the servo response.
But it just refuse to give throttle signal. Both main and tail. I hook up the oscilloscope
up to the MCU motor signal pin, I can't see it.

There are some OCP and LVC protection circuit. I check all that and I can't find
any thing abnormal. It feels like as if the pin on the MCU is burn out.
However, the MCU has current protection so it shouldn't burn out pins.
Any way, if the MCU is bad, that is not some thing I can fix without the
original firmware image.

Any idea how to find out why that MCU is not outputing the motor
signal?

Other than that, I have fix about 10 boards, most of them of them are not
burning FETS type or connect a battery type.

[helifixing]

I have a relatively new v.2 1.3 board which has dropped from the sky a few times so I don't trust it. If useful, I'll donate it for science here if you PM me the shipping details.

[branmuffin]

Originally Posted by helifixing

I have a relatively new v.2 1.3 board which has dropped from the sky a few times so I don't trust it. If useful, I'll donate it for science here if you PM me the shipping details.

[coredump]

Here are some notes on mapping the V2 MCU pin out:
I use the port number rather than chip pin number. You need
read the datasheet to map them back to chip pin number.
The port number is easier for programming.

portA:
[0:2] not used. In V1 it is the gyro analog input.
3: motor ground plug. OCP input.
4: monitor battery Vcc/2
5: main motor output voltage measure
6: tail motor output voltage measure
7: MCU voltage monitor (3v /2)

Port B:
0: connect to porta_7, MCU voltage.
[1:3] Not used

Port C
0: I2c data for gyro
1: i2c clock for gyro
2: Debug port serial out
3: Debug port serial in
4: tail motor pwm
5: main motor pwm
6: LED, push to light it.
7: not used.

port D:
0: Right servo PPM
1: Elervation servo PPM
2: Left servo PPM
3: Not used
4: Receiver data interrupt.
5: Receiver data SPI data
6: Gyro Interrupt (That is the line has receiver data plumb into it)
7: Receiver SPI clock

Port E: not used.