Deep sleep issue on STM32W108

vanja · ‎2013-12-27

Posted on December 27, 2013 at 11:39

Hello,

I am using the STM32W-RFCKIT (MB950 and MB951) to create some prototypes. I've tried both Simple MAC sample applications (sun & planets, talk) version 2.0.1 and Contiki (2.5, 2.6, 2.7). In all of these, everything works as expected except one thing: the deep sleep behavior is not working for me. Whenever the module goes to deep sleep (WFI command) it will halt or reboot.

I've done some debugging, and I think that the rebooting happens when the module is waking up from the deep sleep. Has anybody had a similar experience?

Is Simple MAC 2.0.1 compatible with RFCKIT (mb950 and mb951 from Dizic)? Does anybody know where I could get a hold of older Simple MAC packages, to try if these work better?

Thanks ahead!

#stm32w108-wakeup-simplemac-mb950

jacobb · ‎2014-01-23

Posted on January 23, 2014 at 18:07

I know this is a bit late but I was experiencing a similar issue. I would recommend not trying the write your own sleep mode drivers. I would use the ST provided libraries for sleep mode. I tired something similar to you and I was getting the same issue. If you look closely at the libraries you'll notice that they do a bunch of context saving (registers) right before going to sleep. Then immediately after sleep they restore all of the registers. The core and associated registers are shut down but the RAM still gets power so if you don't save anything you lose all the program context (probably why you were resetting). So like you, I attempted just executing a wfi to go to sleep. That is only the tip of the iceberg. God forbid they actually give a detailed explanation in the data sheet. It's one of the worst data sheets I've ever worked with.