From eb1064eef4b5f5d8bc504a2ca214a4bdc8b416a4 Mon Sep 17 00:00:00 2001
From: Nishchay-sopho <nagrawal@ibr.cs.tu-bs.de>
Date: Wed, 14 Oct 2020 13:37:18 +0200
Subject: [PATCH] drivers/scd30: Add reset function to Sensirion scd30 sensor

---
 drivers/include/scd30.h                |  9 +++++++++
 drivers/scd30/include/scd30_internal.h |  1 +
 drivers/scd30/scd30.c                  | 28 ++++++++++++++++++++++++--
 3 files changed, 36 insertions(+), 2 deletions(-)

diff --git a/drivers/include/scd30.h b/drivers/include/scd30.h
index 08bc44a9e4..edd762c34c 100644
--- a/drivers/include/scd30.h
+++ b/drivers/include/scd30.h
@@ -167,6 +167,15 @@ int scd30_start_periodic_measurement(scd30_t *dev, uint16_t *interval,
  */
 int8_t scd30_stop_measurements(const scd30_t *dev);
 
+/**
+ *  @brief  Soft reset sensor
+ *
+ *  @param dev          scd30 dev device
+ *
+ *  @return             SCD30_OK if soft reset successful
+ */
+int8_t scd30_reset(scd30_t *dev);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/drivers/scd30/include/scd30_internal.h b/drivers/scd30/include/scd30_internal.h
index 2ff9d20719..4ab3f689d0 100644
--- a/drivers/scd30/include/scd30_internal.h
+++ b/drivers/scd30/include/scd30_internal.h
@@ -44,6 +44,7 @@ extern "C" {
                           1013.25 mBar */
 
 #define SCD30_READ_WRITE_SLEEP_US       (4 * US_PER_MS)
+#define SCD30_RESET_SLEEP_US            (25 * US_PER_MS)
 #define SCD30_DATA_RDY_TIMEOUT          (1 * US_PER_SEC)
 
 #define SCD30_MIN_INTERVAL              2
diff --git a/drivers/scd30/scd30.c b/drivers/scd30/scd30.c
index 637b3dfece..c773b7147b 100644
--- a/drivers/scd30/scd30.c
+++ b/drivers/scd30/scd30.c
@@ -45,11 +45,18 @@ static float _raw_val_to_float(const uint8_t *buffer);
 int8_t scd30_init(scd30_t *dev, const scd30_params_t *params)
 {
     DEBUG("[scd30] init\n");
+    int ret = 0;
+    uint16_t version;
+
     dev->params = *params;
 
-    int ret = 0;
+    /* Soft reset sensor */
+    ret = scd30_reset(dev);
+    if (ret < 0) {
+        DEBUG("[scd30] Failed to reset sensor in init\n");
+        return ret;
+    }
 
-    uint16_t version;
     ret = scd30_get_param(dev, SCD30_VERSION, &version);
     DEBUG("[scd30] --- Version 0x%02x%02x\n", (version >> 8), version);
     if (ret < 0) {
@@ -237,6 +244,23 @@ int8_t scd30_stop_measurements(const scd30_t *dev)
     return SCD30_OK;
 }
 
+int8_t scd30_reset(scd30_t *dev)
+{
+    const uint16_t cmd = htons(SCD30_SOFT_RESET);
+    int ret;
+
+    i2c_acquire(SCD30_I2C);
+    ret = i2c_write_bytes(SCD30_I2C, SCD30_I2C_ADDRESS, &cmd, 2, 0);
+    i2c_release(SCD30_I2C);
+
+    if (ret != 0) {
+        DEBUG("[scd30]: Error resetting sensor.\n");
+        return ret;
+    }
+    xtimer_usleep(SCD30_RESET_SLEEP_US);
+    return SCD30_OK;
+}
+
 /**
  *      intern function to read data
  *