Initial (empty) Si7021 driver

src/mgos_si7021_internal.h

@@ -0,0 +1,38 @@
+#pragma once
+
+#include "mgos.h"
+#include "mgos_i2c.h"
+#include "mgos_si7021.h"
+#include <math.h>
+
+#define MGOS_SI7021_DEFAULT_I2CADDR       (0x40)
+
+#define MGOS_SI7021_MEASRH_HOLD_CMD       (0xE5)
+#define MGOS_SI7021_MEASRH_NOHOLD_CMD     (0xF5)
+#define MGOS_SI7021_MEASTEMP_HOLD_CMD     (0xE3)
+#define MGOS_SI7021_MEASTEMP_NOHOLD_CMD   (0xF3)
+#define MGOS_SI7021_READPREVTEMP_CMD      (0xE0)
+#define MGOS_SI7021_RESET_CMD             (0xFE)
+#define MGOS_SI7021_WRITERHT_REG_CMD      (0xE6)
+#define MGOS_SI7021_READRHT_REG_CMD       (0xE7)
+#define MGOS_SI7021_WRITEHEATER_REG_CMD   (0x51)
+#define MGOS_SI7021_READHEATER_REG_CMD    (0x11)
+#define MGOS_SI7021_ID1_CMD               (0xFA0F)
+#define MGOS_SI7021_ID2_CMD               (0xFCC9)
+#define MGOS_SI7021_FIRMVERS_CMD          (0x84B8)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct mgos_si7021 {
+  struct mgos_i2c *i2c;
+  uint8_t i2caddr;
+  double last_read_time;
+
+  float humidity, temperature;
+};
+
+#ifdef __cplusplus
+}
+#endif