So I have this FTDI adapter that I use so I can send serial data to 2 arduinos at the same time (I only intend to receive from 1 at a time). This works perfectly fine so far. The problem is whether both arduinos are connected or not, I can't seem to upload code to either one, it just simply fails. Any suggestions?
How are you connected, and what error message do you get back?
I connect the adapter's RX pin to one of the arduinos' pin 1, and the TX pin to pin 2 of both arduinos. I can see the issue - normally when you upload a code, the arduino and computer talk to each other at the same time, but when I upload the code using this adapter, the arduino receives but it doesn't send back. The adapter will both send and receive when a program is running, so I know it can't just be the adapter.
How are you resetting the arduino so the bootloader kicks in & looks for the incoming message?
I wasn't aware I had to do that. What would you recommend?
Press & hold the reset button, release it when the IDE says "compiled xxx of 32xxx bytes", something like that.
May have to try releasing a few tries to find the right time, is not an exact science.
ok well thanks for the info. Any possibility this can be invoked through software, much like the built-in setup?
To do that, you need to bring the DTR pin on the FTDI adapter thru a 0.1uF cap to the board's reset pin.