From 599a455150d085209c5f0314cbdbaa9d59e0be36 Mon Sep 17 00:00:00 2001
From: Donovan Baarda <abo@minkirri.apana.org.au>
Date: Mon, 8 Aug 2022 05:50:15 +1000
Subject: [PATCH] Add a soft reset in setup() for bme280. (#3615)

---
 esphome/components/bme280/bme280.cpp | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/esphome/components/bme280/bme280.cpp b/esphome/components/bme280/bme280.cpp
index a4ea8d608e..345b24a36e 100644
--- a/esphome/components/bme280/bme280.cpp
+++ b/esphome/components/bme280/bme280.cpp
@@ -1,4 +1,5 @@
 #include "bme280.h"
+#include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 
 namespace esphome {
@@ -28,6 +29,7 @@ static const uint8_t BME280_REGISTER_DIG_H5 = 0xE5;
 static const uint8_t BME280_REGISTER_DIG_H6 = 0xE7;
 
 static const uint8_t BME280_REGISTER_CHIPID = 0xD0;
+static const uint8_t BME280_REGISTER_RESET = 0xE0;
 
 static const uint8_t BME280_REGISTER_CONTROLHUMID = 0xF2;
 static const uint8_t BME280_REGISTER_STATUS = 0xF3;
@@ -39,6 +41,8 @@ static const uint8_t BME280_REGISTER_TEMPDATA = 0xFA;
 static const uint8_t BME280_REGISTER_HUMIDDATA = 0xFD;
 
 static const uint8_t BME280_MODE_FORCED = 0b01;
+static const uint8_t BME280_SOFT_RESET = 0xB6;
+static const uint8_t BME280_STATUS_IM_UPDATE = 0b01;
 
 inline uint16_t combine_bytes(uint8_t msb, uint8_t lsb) { return ((msb & 0xFF) << 8) | (lsb & 0xFF); }
 
@@ -97,6 +101,28 @@ void BME280Component::setup() {
     return;
   }
 
+  // Send a soft reset.
+  if (!this->write_byte(BME280_REGISTER_RESET, BME280_SOFT_RESET)) {
+    this->mark_failed();
+    return;
+  }
+  // Wait until the NVM data has finished loading.
+  uint8_t status;
+  uint8_t retry = 5;
+  do {
+    delay(2);
+    if (!this->read_byte(BME280_REGISTER_STATUS, &status)) {
+      ESP_LOGW(TAG, "Error reading status register.");
+      this->mark_failed();
+      return;
+    }
+  } while ((status & BME280_STATUS_IM_UPDATE) && (--retry));
+  if (status & BME280_STATUS_IM_UPDATE) {
+    ESP_LOGW(TAG, "Timeout loading NVM.");
+    this->mark_failed();
+    return;
+  }
+
   // Read calibration
   this->calibration_.t1 = read_u16_le_(BME280_REGISTER_DIG_T1);
   this->calibration_.t2 = read_s16_le_(BME280_REGISTER_DIG_T2);