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SPI: Fix prescaler at low baudrates #794

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Merged
merged 2 commits into from
Nov 27, 2019
Merged

SPI: Fix prescaler at low baudrates #794

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858699c
Fix prescaler at low baudrates
LinoBarreca Nov 26, 2019
cca16e3
Modified comment and removed double check
LinoBarreca Nov 26, 2019
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8 changes: 5 additions & 3 deletions cores/arduino/stm32/spi_com.c
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Original file line number Diff line number Diff line change
Expand Up @@ -213,10 +213,12 @@ void spi_init(spi_t *obj, uint32_t speed, spi_mode_e mode, uint8_t msb)
handle->Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_64;
} else if (speed >= (spi_freq / SPI_SPEED_CLOCK_DIV128_MHZ)) {
handle->Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_128;
} else if (speed >= (spi_freq / SPI_SPEED_CLOCK_DIV256_MHZ)) {
handle->Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256;
} else {
handle->Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_16;
/*
* As it is not possible to go below (spi_freq / SPI_SPEED_CLOCK_DIV256_MHZ).
* Set prescaler at max value so get the lowest frequency possible.
*/
handle->Init.BaudRatePrescaler = SPI_BAUDRATEPRESCALER_256;
}

handle->Init.Direction = SPI_DIRECTION_2LINES;
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