update

src/max31856.cpp

@@ -0,0 +1,78 @@
+#include "pico/stdlib.h"
+#include "hardware/spi.h"
+#include <stdint.h>
+
+#include "max31856.h"
+
+// max31856 pins
+#define SPI_MAX31856            spi0
+#define SPI_MAX31856_BOUD       1E6 // 1 MHz (max31856 can go up to 5 MHz)
+#define SPI_MAX31856_SPO        SPI_CPOL_0
+#define SPI_MAX31856_SPH        SPI_CPHA_1
+#define SPI_MAX31856_BIT_ORDER  SPI_MSB_FIRST
+#define SPI_MAX31856_BLOCK_SIZE 8
+
+void max31856_init(max31856_t *max)
+{
+   // init GPIO for CS
+   gpio_init(max->pin_cs);
+   gpio_set_dir(max->pin_cs, GPIO_OUT);
+   gpio_put(max->pin_cs, 1);
+
+   // init SPI
+   spi_init(SPI_MAX31856, SPI_MAX31856_BOUD);
+   spi_set_format(SPI_MAX31856, SPI_MAX31856_BLOCK_SIZE, SPI_MAX31856_SPO, SPI_MAX31856_SPH, SPI_MAX31856_BIT_ORDER);
+
+   max->initilzed = true;
+}
+
+void max31856_deinit(max31856_t *max)
+{
+   max->initilzed = false;
+   spi_deinit(SPI_MAX31856);
+   gpio_deinit(max->pin_cs);
+}
+
+int max31856_write8(max31856_t *max, uint8_t addr, uint8_t value)
+{
+   if (!(max->initilzed))
+   {
+      return -1;
+   }
+   uint8_t buff[2] = {addr | 0x80, value};
+   gpio_put(max->pin_cs, 0);
+   spi_write_blocking(SPI_MAX31856, &buff[0], 2);
+   gpio_put(max->pin_cs, 1);
+
+   return 0;
+}
+
+uint8_t max31856_read8(max31856_t *max, uint8_t addr)
+{
+   if (!(max->initilzed))
+   {
+      return -1;
+   }
+   uint16_t buff_tx = (addr & 0x7F)<<8;
+   uint8_t buff_rx[] = {0, 0};
+   gpio_put(max->pin_cs, 0);
+   spi_read_blocking(SPI_MAX31856, buff_tx, &buff_rx[0], 2);
+   gpio_put(max->pin_cs, 1);
+
+   return buff_rx[1];
+}
+
+uint16_t max31856_read16(max31856_t *max, uint8_t addr)
+{
+   if (!(max->initilzed))
+   {
+      return -1;
+   }
+   uint16_t buff_tx = (addr & 0x7F)<<8;
+   uint8_t buff_rx[] = {0, 0, 0};
+   gpio_put(max->pin_cs, 0);
+   spi_read_blocking(SPI_MAX31856, buff_tx, &buff_rx[0], 3);
+   gpio_put(max->pin_cs, 1);
+
+   return buff_rx[1]<<8 | buff_rx[2];
+}