stm32f373 nrf24l01+ Cannot set tx addr after flush_tx

[Joe Wright]

Hi, I'm trying to adapt the stm32f4 library from:

link text

to run an nrf24l01+ with an stm32f373. After some initial SPI headaches, a lot is working. In the initialisation code a lot of stuff is being written to, and read back, with expected behaviour.

The odd thing is, I cannot set the tx address (and rx_addr_p0) after a FLUSH_TX has been sent. The flush is in the init code, and I have debugged it to the point where, before that line, I can set a tx address, but cannot afterwards.

Setting the rx_addr_p1 isn't affected and works fine.

Any ideas what I should look for in debugging this?

Thanks, Joe

[Hung Bui]

@Joe: What happened when you try to set the address after you call FLUSH_TX? If you read it out, what do you have ?

[Joe Wright]

When I read it I get the value that was set prior to the first FLUSH_TX. As a quick fix I've edited the default values in the initialisation code to reflect what I wanted to set it to. But I haven't got a connection working yet and so I don't want any unexplained elements in case that's what's preventing the successful connection.

[Joe Wright]

Ok, it seems I'm getting some pretty strange behaviour. Depending on where I set it in the sequence of initialisation, it either works or doesn't. Right after FLUSH_TX and the rx_addr_p0 cannot be set. But after clearing interrupts both can be set. But then later on neither can be set. Will continue trying to work out what is going on...

[Joe Wright]

If I do things like put a delay before setting a value, it sticks more often than not. I'm therefore thinking that my problem is more to do with how I've configured the SPI or how I'm doing the transfers. Will investigate more then close this with the answer if I find it. Bit of a step up form using Arduinos and Teensy's...

[Joe Wright]

I got a logic analyser and found some timing issues with the library I was using. Especially, CSN was coming up just before the final clock pulse had finished.

Added a delay, all working now.