VERY IMPORTANT ISSUE ABOUT TIMMING in TRW-2.4G

Wireless & IoT
1

Hi I hope this could help you as you always help me :wink:

I had this well known modules working with SPI in ShockBurst at 1Mbps (between uC and TRW-2.4G). But I couldn’t make them work at a lower SPI speed, and that was driving my crazy :twisted:

Long time I’ve been cracking my head until I got and epiphany :idea:

That’s what I was doing before:

  • CS=1 CONFIG MODE

  • CE=0

  • SEND CONFIG WORD

  • CS=0

  • delay of few micro-sec

with that it works at 1Mbps

then I do this:

  • CS=1 CONFIG MODE

  • CE=0

  • SEND CONFIG WORD

  • delay of few micro-sec

  • CS=0

and I were able to work at 250k, but it won’t work at a lower speed

and finally:

  • CS=1 CONFIG MODE

  • CE=0

  • SEND CONFIG WORD

  • delay of 3ms

  • CS=0

and HERE WE GO, now I’m at 10K

Is very odd… I don’t know why the delay deppends on the Speed

I couldn’t find anything about that in the data sheet, nor even about this delay, and in my opinion it is crucial!

The idea of that delay came as I think I could be a good idea to give the CS line a remain-high time, and it was also very logical. But don’t ask why this delay is connected to de SPI speed…

If you notice anything else please, share your experience.

Good LUCK

/SebaS S8)