From 9e5b3318442f978c74a115c46682efaef523534b Mon Sep 17 00:00:00 2001
From: Hendrik Langer <hendrik+dev@xd0.de>
Date: Sun, 11 Feb 2018 13:28:58 +0100
Subject: [PATCH] hw SPI for bme

---
 src/BME280.cpp | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/src/BME280.cpp b/src/BME280.cpp
index ac7accd..b13865e 100644
--- a/src/BME280.cpp
+++ b/src/BME280.cpp
@@ -10,24 +10,26 @@ BME280::BME280() {
 }
 
 bool BME280::begin(void) {
-//  SPI.begin(BME_SCK, BME_MISO, BME_MOSI, BME_CS);
+  SPI.begin(BME_SCK, BME_MISO, BME_MOSI, BME_CS);
   pinMode(18, OUTPUT);
   digitalWrite(18, HIGH); // disable LoRa_CS
   pinMode(BME_CS, OUTPUT);
   digitalWrite(BME_CS, LOW);  // enable bme280 CS
   delay(100);
-  bme = new Adafruit_BME280(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
-  valid = bme->begin();
-  if (!valid) bme->init();
-  if (!valid) return false;
+//  bme = new Adafruit_BME280(BME_CS, BME_MOSI, BME_MISO, BME_SCK); // software SPI
+  bme = new Adafruit_BME280(BME_CS); // hardware SPI
 
   bme->setSampling(Adafruit_BME280::sensor_mode::MODE_NORMAL,
-                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
-                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
-                   Adafruit_BME280::sensor_sampling::SAMPLING_X16,
+                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
+                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
+                   Adafruit_BME280::sensor_sampling::SAMPLING_X8,
                    Adafruit_BME280::sensor_filter::FILTER_OFF,
                    Adafruit_BME280::standby_duration::STANDBY_MS_250);
 
+  valid = bme->begin();
+  if (!valid) bme->init();
+
+  if (!valid) return false;
   return true;
 }
 
@@ -44,20 +46,28 @@ bool BME280::reinit() {
   pinMode(18, OUTPUT);
   digitalWrite(18, HIGH); // disable LoRa_CS
   pinMode(BME_CS, OUTPUT);
-  digitalWrite(BME_CS, LOW);  // enable bme280 CS
+//  digitalWrite(BME_CS, LOW);  // enable bme280 CS
 
   int retries = 0;  valid = false;
   while (!valid) {
     if (retries > 9) break;
+    /* reset chip */
+    Serial.println("resetting BME280");
+    SPI.beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
+    digitalWrite(BME_CS, LOW);
+    constexpr byte BME280_REGISTER_SOFTRESET = 0xE0;
+    SPI.transfer(BME280_REGISTER_SOFTRESET & ~0x80);
+    SPI.transfer(0xB6);
+    digitalWrite(BME_CS, HIGH);
+    SPI.endTransaction(); // release the SPI bus
+    delay(300); // wait for chip to wake up
+
     valid = bme->init();
     retries++;
 
-    delay(100);
     float p = bme->readPressure() / 100.0F;
     if (p < 300 || p > 1100) valid = false;
 
-//    constexpr byte BME280_REGISTER_SOFTRESET = 0xE0;
-//    bme->write8(BME280_REGISTER_SOFTRESET, 0xB6);
   }
   if (!valid) {
     Serial.println("Could not find a valid BME280 sensor, check wiring!");