Nano Serial to Flip 1.5 Multiwii

I’m trying to get data from a Flip MWC over to my Nano using Multiwii Serial but am not receiving any response from the Flip.

Here’s my bench set up:
Flight controller: Flip MWC 1.5
Code: MWC 2.3 MultiWii_Flip_Tri
Arduino Nano V3.1

I started with some code posted on the Multiwii forum (renes “SD Card Logger”) and updated it to use SoftwareSerial on the Nano and checked out this connection using a standalone Adafruit GPS board
Hookups: Nano (TX (D8), RX(D7), Gnd) to Flip (RX, TX, Gnd)
(This lets me use the ‘hardware’ serial connection for the Arduino IDE Serial Monitor for debugging)

Datalogger.ino code attached
The serial connections seems to initialize (line 35)
The Arduino sends the data request out ( line 51 Note, Protocol.h has been modified for mySerial() )
but I don’t get any response from readData(); (line 64)

What am I missing?
Is there something specific to the Flip MWC serial connection?
Do I need to configure something in the Multiwii code itself?

Any advice would be very much appreciated!

Regards
Adrian Land

datalogger_al1.ino (2.76 KB)

This is not a legitimate check to see if serial communication has been established. I'm pretty certain it will always return true even if completely disconnected:

 mySerial.begin(115200);
  while (!mySerial) {
    ; 
  }// wait for Flip to be ready
  
  Serial.println("Setup loop okay");

Aside from that there's too much of the code missing; you haven't provided the "protocol.h" header, etc., so there are variables like "c_state" that have no clear assignment.

I'd also suggest that you echo to your hardware serial port (your debugging messages) everything that comes from mySerial.read(). E.g.:

Serial.print("myserial.read okay: ");
Serial.println(c, HEX);