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ws2812b: use push-pull output for noisy cable

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King Kévin 2020-06-21 09:54:56 +02:00
parent 4f91856445
commit ac9eb9bac9
1 changed files with 3 additions and 3 deletions
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6
lib/led_ws2812b.c
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@ -39,9 +39,9 @@
* @{
*/
/** SPI peripheral
* @note SPI2 is 5V tolerant and can be operated in open-drain mode will 1 kO pull-up resistor to 5V to get 5V signal level
* @note SPI2 is 5V tolerant and can be operated in open-drain mode with 1-10 kO pull-up resistor to 5V to get 5V signal level for short cables
*/
#define LED_WS2812B_SPI 2 /**< SPI peripheral */
#define LED_WS2812B_SPI 2 /**< SPI peripheral (SPI2_MOSI = PB15) */
/** @} */
/** bit template to encode one byte to be shifted out by SPI to the WS2812B LEDs
@ -108,7 +108,7 @@ void led_ws2812b_setup(void)
// setup SPI to transmit data
rcc_periph_clock_enable(RCC_SPI_MOSI_PORT(LED_WS2812B_SPI)); // enable clock for SPI output peripheral
gpio_set_mode(SPI_MOSI_PORT(LED_WS2812B_SPI), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_OPENDRAIN, SPI_MOSI_PIN(LED_WS2812B_SPI)); // set MOSI as output (push-pull needs to be shifted to 5V, open-drain consumes up to 5 mA with pull-up resistor of 1 kO)
gpio_set_mode(SPI_MOSI_PORT(LED_WS2812B_SPI), GPIO_MODE_OUTPUT_50_MHZ, GPIO_CNF_OUTPUT_ALTFN_PUSHPULL, SPI_MOSI_PIN(LED_WS2812B_SPI)); // set MOSI as output (push-pull, works better for long noisy cables, also works well enough without voltage shifter)
rcc_periph_clock_enable(RCC_AFIO); // enable clock for SPI alternate function
rcc_periph_clock_enable(RCC_SPI(LED_WS2812B_SPI)); // enable clock for SPI peripheral
spi_reset(SPI(LED_WS2812B_SPI)); // clear SPI values to default