Add DS75LX temperature driver.

Makefile

@@ -50,6 +50,7 @@ USEMODULE += $(DRIVER)
 USEMODULE += random
 USEMODULE += periph_eeprom
 USEMODULE += periph_uart
+USEMODULE += periph_i2c
 
 
 # Source directory is "src".

src/app/drivers/ds75lx.c

+/*
+
+Driver for the DS75LX digital thermometer.
+
+Copyright (C) 2019, ENSIMAG students
+This file is based on DS75LX module from IBM LMIC, under Eclipse Public License
+v1.0.
+
+*/
+
+#include "ds75lx.h"
+
+#define ENABLE_DEBUG (1)
+#include <debug.h>
+
+
+// I2C registers.
+#define TEMP_REG    0x00  // Temperature register.
+#define CONFIG_REG  0x01  // Configuration register.
+
+// Masks to extract the concerned bits.
+#define MASK_RESOLUTION  0x60  // 0b01100000
+
+
+// Debug an I2C result.
+#define DS75_DEBUG(text, res)  \
+    if ((res) != 0) DEBUG("[ds75]" text ": %i\n", (res));
+
+
+// Initialize DS75LX module.
+uint8_t ds75_init(void)
+{
+    i2c_acquire(DS75_I2C_DEV);
+    int res = i2c_write_reg(DS75_I2C_DEV, DS75_I2C_ADDRESS, CONFIG_REG, DS75_RES9, 0);
+    i2c_release(DS75_I2C_DEV);
+
+    DS75_DEBUG("initialize error", res);
+    return res;
+}
+
+
+// Set the resolution of DS75LX chip.
+uint8_t ds75_set_resolution(uint8_t resol)
+{
+    uint8_t config;
+
+    i2c_acquire(DS75_I2C_DEV);
+	int res = i2c_read_reg(DS75_I2C_DEV, DS75_I2C_ADDRESS, CONFIG_REG, &config, 0);
+    DS75_DEBUG("read config error", res);
+
+    config &= ~MASK_RESOLUTION;
+    config |= resol;
+
+    res = i2c_write_reg(DS75_I2C_DEV, DS75_I2C_ADDRESS, CONFIG_REG, DS75_RES9, 0);
+    i2c_release(DS75_I2C_DEV);
+
+    DS75_DEBUG("set resolution error", res);
+    return res;
+}
+
+
+// Read temperature from DS75LX chip.
+uint8_t ds75_read_temperature(uint16_t *temp)
+{
+	uint8_t buffer[2];
+
+    i2c_acquire(DS75_I2C_DEV);
+	int res = i2c_read_regs(DS75_I2C_DEV, DS75_I2C_ADDRESS, TEMP_REG, buffer, 2, 0);
+    i2c_release(DS75_I2C_DEV);
+
+	*temp = (buffer[0] << 8) | buffer[1];
+
+    DS75_DEBUG("read temp error", res);
+	return res;
+}

src/app/drivers/ds75lx.h

@@ -3,9 +3,50 @@
 Driver for the DS75LX digital thermometer.
 
 Copyright (C) 2019, ENSIMAG students
-This file is based on DS75LX module from IBM LMIC, under Eclipse Public License
-v1.0.
+This project is under the MIT license
 
 */
 
 #pragma once
+
+#include <periph/i2c.h>
+
+
+// Return codes.
+#define DS75_SUCCESS  0
+#define DS75_FAIL     1
+
+
+// Default device to use.
+#define DS75_I2C_DEV  (I2C_DEV(0))
+
+// Default I2C address to use.
+#define DS75_I2C_ADDRESS  (0x68)
+
+
+// DS75LX resolution.
+#define DS75_RES9   0x00
+#define DS75_RES10  0x20
+#define DS75_RES11  0x40
+#define DS75_RES12  0x60
+
+
+/**
+ * @brief Initialize DS75LX module.
+ * @return `DS75_SUCCESS` or I2C error code.
+ */
+uint8_t ds75_init(void);
+
+/**
+ * @brief Set the resolution of DS75LX chip.
+ * @param resol The resolution to use.
+ * @return `DS75_SUCCESS` or I2C error code.
+ */
+uint8_t ds75_set_resolution(uint8_t resol);
+
+/**
+ * @brief Read temperature from DS75LX chip.
+ * @param temp Where to store the result.
+ * @return `DS75_SUCCESS` or I2C error code.
+ */
+uint8_t ds75_read_temperature(uint16_t *temp);

src/app/drivers/gps.h

@@ -3,7 +3,7 @@
 Decode GPS data.
 
 Copyright (C) 2019, ENSIMAG students
-This file is based on LoRaMAC-node from Semtech, under Revised BSD License.
+This project is under the MIT license
 
 */
 

src/app/main.c

@@ -8,6 +8,7 @@ This project is under the MIT license
 */
 
 #include "lorariot.h"
+#include "drivers/ds75lx.h"
 #include "providers/providers.h"
 #include "commands/commands.h"
 
@@ -18,6 +19,7 @@ This project is under the MIT license
 int main(void)
 {
     lorariot_init();
+    ds75_init();
     cmds_init();
 
 #if RESET_ON_START