PIC hangs after interrupt when FT232RL is connected

[Demon]

I bought one of these boards on amazon to help with debugging:



https://www.amazon.ca/gp/product/B075N82CDL/


The PIC hangs after the first timer interrupt is triggered. The FT232 is connected to VSS and TX/RX which is wired to and RX/TX on a 2nd PIC (4K7 pull-ups).

If I unplug the USB cable and reset the circuit, the PIC starts up and loops as expected.

Is there something we should be aware of when using these?

[richard]

What steps did you take to make the output of the adapter open collector so that it won't clash with the pics outputs on your bus.?
Are you sure it's correctly connected, arduino things are often labelled to show the arduino pin they connect to, making rx the output tx the input

[Demon]

What steps did you take to make the output of the adapter open collector so that it won't clash with the pics outputs on your bus.? ...

None that I know of. I'm using the Serial Communicator from MCSP+ 5.0.0.5. on the PC side.

... Are you sure it's correctly connected, arduino things are often labelled to show the arduino pin they connect to, making rx the output tx the input

The adapter has RX/TX labels. I connected them in relation to the PC - not the PIC.


I reconnected the whole circuit now, and it works...? I don't know why, I didn't change anything except recompiled with the HSEROUTs enabled again.

1. The only difference is that I rebooted the PC today. The only thing I can imagine is that the adapter was somehow disturbing the PIC USART even if it was only sending, there is no HSERIN code.

2. I have noticed recently that I have to shut MCSP+ down because it no longer sees INCLUDES and stuff like that (I can't remember what exactly). I would just restart MCSP= and the compile would work without errors.


I hate intermittent problems...

[pedja089]

There is probablu RX interupt when connected, and it is not handled correctly for what ever reason.