I got there in the end with my avalon 6. Its runing direct from the Pi 3 board.
Would really like to know how you managed this.
Yes, for sure. Is it possible to connect RPi headers using cables (such as https://www.amazon.es/gp/product/B01NGTXASZ or https://www.ebay.com/itm/Dupont-Jumper-Wire-Cable-Female-Male-20cm-20pcs-for-Arduino/222709027859) so as to avoid solder?