Monday, November 12, 2012

FrSKY D8R-II Plus Firmware Upgrade To D8R-XP With CPPM 27ms.

My receiver is FrSKY D8R-II plus.
Today, I uploaded the firmware to D8R-XP.
(I search from internet. D8R-II plus & D8R-XP hardware they look like the same.)
Why would I want to do this?
That has several advantages.
First, I want to use CPPM between receiver and control board, only one cable transfer CH1~CH8 signal.
Second, I can got RSSI for signal level.

Because the FrSKY had some issue on CPPM mode, in this reason, I suggest don’t use more then 6 channel on CPPM mode.
You can see D8R-XP user manual on FrSKY website, the user manual say “CPPM channel can not handle all eight channels at the same time with all throws are maxed out, as it does not have enough frame gap. It is recommended to use at most six channels from CPPM channel while leaving off the rest two channels, otherwise improper performance might occur.”.

And you can look into the following URL.

FrSKY release firmware (beta version) that CPPM 27ms for D8R-XP to fix this issue.
Beta version firmware on FrSKY website, include upload procedure.
I use this way (see following URL) to uploaded firmware.

I use USB to TTL element, FTDI chip, work very well.


  1. Seem's very good , how abort your test?

    1. Just tested at home. CPPM work fine. RSSI haven't test.

  2. Hi, did u have to cut the 5v trace and join the 3.3v trace on your FTDI USB adapter?
    I happen to have the same board but saw the 3.3v note on the diydrones forum and have a trace on my ftdi usb board to select 3.3v or 5v

    1. Hi ,I didn't [cut the 5v trace and join the 3.3v trace].
      I didn't change any electric circuit on FTDI USB adapter.
      I used the 3.3V out from FTDI USB adapter.

  3. Thank you for sharing this! Are you using a USB TTL cable or USBASP? Can you clarify what pin from the cable is connected to what pin on the D8R-II Plus? Is it 3.3V to any (+) pin (you chose ch4); GND to any (-) pin (you chose ch1); Tx to Rx on the D8R; Rx to Tx on the D8R? Thanks again.

    1. I used USB TTL.
      Yes, the 3.3V to any(+) pin,Gnd to any(-) pin.
      I forget the connection way of TX RX pin, but I think "USB TTL TX to D8R-II plus RX" and "USB TTL RX to D8R-II plus TX", if can't communication just change RX TX pin, change RX TX pin will not damage device.