Hi everybody

I try to use a Key Matrix, but I cannot get the slave card connected to the atmega. I tried with a UNO card and a NANO card, so I think that I`m doing something wrong.

- I have an ATMEGA 2560 with a ethernet shield connected to xplane without problems. I use an USB source connected to a wall AC plug.

- To charge firmware to the UNO/NANO, I connect the following pins between the master and the slave card:

- Master TX1(19) to slave RX0, Master RX1(18) to slave TX1. Master 5v to slave Vin. Groun in master o slave ground.

- Start Xplane11 and then go to upload firmware.

- When tell me about connect the card to USB, I connect a USB cable between the computer and the slave card.

- When detected, choose Matrix firmware and the slave type and then upload, with the rxtx disconnected.

- Unplug USB and connect again the rxtx

- While I keep the usb connected, Simvim recognizes a Serial card pluged.

- When I unplug the USB cable, never connects again and no recognizes any slave card at all.

Am I doing something wrong??

Another question, do you need diodes connected to the buttons when you build the matrix, like in ardsimx??

Thanks in advance
in Hardware by

1 Answer

0 votes

First,  check your Mega board - some of the clones may have wrong marking (lettering only). As you wrote you have TX1(pin 19) and RX1(pin 18), but this is wrong.

Correct is as in the diagram on this page - http://simvim.com/svc_matrix.html  (Tx1=pin18, Rx1=pin18 - the same as Tx2,Tx3).

Second, when uploading follow the rules described on the page (see Note2).

As for diodes - you need them only if you need two buttons to be pressed simultaneously.