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STM32F103C8T6 (Blue Pill) Multiple Peripheral and DMA

Posted: Wed Jul 26, 2017 12:43 am
by rbarreiros
Hello,

I'm in need of the following peripherals, UART1, UART2, UART3, SPI(1 or 2), and I2C(1 or 2), but STM32F103 shares many DMA channels with these peripherals.

The UARTs are generating DMX with strict and precise timings, so I'd guess that it would be best to keep the DMA with the UARTs and use I2C (EEPROM) and SPI (ENC28J60) without DMA, but how would I go on about disabling DMA in SPI and I2C on ChibiOS ?

Best regards.

Re: STM32F103C8T6 (Blue Pill) Multiple Peripheral and DMA

Posted: Wed Jul 26, 2017 7:33 am
by rew
I don't think that all drivers have an alternative to "use DMA" implemented. On SPI I think there is a "for small exchanges don't use DMA" variant of the API. If you cheat and use it for all transfers, that might work.

If you're not making hundreds you might be better off with a slightly bigger CPU... (i.e. F405)