ChibiOS Free Embedded RTOS

It is very simple: You can run it from the external crystal bypassing the PLL. The settings are in mcuconf.h, a good read of the clock three in the RM is recommended.

I knew the clock tree, but didn't realize that for the current consumption measurements ST only used the PLL for clock ...

Hi all,

I've developed some code for the STM32F4 on the Discovery and before starting on my own hardware design I'd like to trim the code for minimal power consumption. I already played around with different values for STM32_HPRE and STM32_PPRE1, but obviously I can't go below STM32_PPRE1 == STM32 ...

Hi again,

indeed SCK *and* MCK are both only there upon transfers. After setting up DMA I saw MCK immediately and it's off as soon as the transfer is finished.

It's nothing related to ChibiOS, I was just misled by the I2S schematics in the ST32F4 documentation (Chapter 27.4, Figure 287) which does ...

Hi,

thanks Giovanni for the quick reply, ChibiOS is a great effort! I have to admit that this is my first STM32F4 project, depite being familiar with ARM and microcontrollers in general and I also know how to use a scope.

An SPI driver may indeed be more elegant, but in my view I should also get ...

Hi,

I know this topic has been on the board multiple times and I definitely read all those threads. The one that seems to come closest to my symptoms seems to be http://forum.chibios.org/phpbb/viewtopic.php?f=8&t=745, but unfortunately that one doesn't contain any solution.

I'm trying to output ...