Uart not always transmitting

Hardware
#1

I’m connecting my imp to a 3.3v Arduino through the UART

Transmitting from Arduino -> Imp works every time

Transmitting from Imp -> Arduino only works sometimes, cycling the power on both can get this to work, but it seems random.

uart setup:
hardware.uart12.configure(115200, 8, PARITY_NONE, 1, NO_CTSRTS, readserial);

uart send:
hardware.uart12.write(“hello\r
”);
hardware.uart12.flush();
server.log(“flags:”+hardware.uart12.flags());

The server will report the flags, which will be either 2 or 66, which looks like ‘WRITE_DONE’ or ‘WRITE_DONE + LINE_IDLE’

I have tried this on 2 different imp boards, although only 1 Arduino so far.

I think this is an issue with the transmit, as I’ve connected the serial monitor to the imp uart output and seen nothing come through.

Any help appreciated, thanks!

#2

That was it, pin 1 wasn’t connecting.

I added a small blob of solder to the pin on the imp and everything it working reliably now.

Thanks!

#3

Is this an imp001 in a socket? There was an issue with making bad connections on pin1 (which is the transmit pin for uart12). See this thread.

Peter

#4

Hi Peter

Yes it is an imp001, and yes I’m using uart12. A physical issue like that would certainly explain why the problem is intermittent.

I’ll check it out later and see if that is the issue.

Thanks!

Richard

#5

btw if you have an imp with bad pin 1, then contact us and we can replace it for you.