feat(api): add implementation for 4-wire SPI

malokhvii-eduard · Oct 26, 2021 · ff10840 · ff10840
1 parent 4ddc221
commit ff10840
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Showing 2 changed files with 118 additions and 2 deletions.
diff --git a/include/Bme280.h b/include/Bme280.h
@@ -1,16 +1,17 @@
 #ifndef ARDUINO_BME280_INCLUDE_BME280_H_
 #define ARDUINO_BME280_INCLUDE_BME280_H_
 
-#include <math.h>
 #include <stdint.h>
 
 #ifndef ARDUINO_BME280_UNIT_TEST
 /* Arduino */
+#include <SPI.h>
 #include <Wire.h>
 
 #define __NOT_VIRTUAL_METHOD
 #else
 /* Mocks */
+#include <mocks/SPI.h>
 #include <mocks/Wire.h>
 
 #define __NOT_VIRTUAL_METHOD virtual
@@ -286,7 +287,33 @@ class Bme280TwoWire final : public ::internal::AbstractBme280 {
   TwoWire *wire_;
 };
 
-// TODO: class Bme280FourWire {};
+class Bme280FourWire final : public ::internal::AbstractBme280 {
+ public:
+  virtual ~Bme280FourWire();
+
+  void begin(const uint8_t csPin);
+  void begin(const uint8_t csPin, SPIClass *spi);
+
+  uint8_t getCsPin() const;
+
+ private:
+  union ControlByte {
+    struct {
+      uint8_t registerAddress : 7;
+      uint8_t rw : 1;
+    };
+    uint8_t value;
+  };
+
+  void write8(const uint8_t registerAddress, uint8_t value);
+  uint8_t read8(const uint8_t registerAddress) const;
+  uint16_t read16(const uint8_t registerAddress) const;
+  uint32_t read24(const uint8_t registerAddress) const;
+
+  uint8_t csPin_;
+  SPIClass *spi_;
+  static const SPISettings spiSettings_;
+};
 
 #undef __NOT_VIRTUAL_METHOD
 

diff --git a/src/Bme280.cc b/src/Bme280.cc
@@ -291,3 +291,92 @@ uint32_t Bme280TwoWire::read24(const uint8_t registerAddress) const {
 
   return value;
 }
+
+Bme280FourWire::~Bme280FourWire() {}
+
+const SPISettings Bme280FourWire::spiSettings_ =
+    SPISettings(SPISettings(500000, MSBFIRST, SPI_MODE0));
+
+void Bme280FourWire::begin(const uint8_t csPin) { begin(csPin, &SPI); }
+
+void Bme280FourWire::begin(const uint8_t csPin, SPIClass *spi) {
+  spi_ = spi;
+  csPin_ = csPin;
+
+  pinMode(csPin_, OUTPUT);
+  digitalWrite(csPin_, HIGH);
+
+  setup();
+}
+
+uint8_t Bme280FourWire::getCsPin() const { return csPin_; }
+
+void Bme280FourWire::write8(const uint8_t registerAddress, uint8_t value) {
+  ControlByte control;
+  control.registerAddress = registerAddress;
+  control.rw = 0;
+
+  spi_->beginTransaction(spiSettings_);
+  digitalWrite(csPin_, LOW);
+
+  spi_->transfer(control.value);
+  spi_->transfer(value);
+
+  digitalWrite(csPin_, HIGH);
+  spi_->endTransaction();
+}
+
+uint8_t Bme280FourWire::read8(const uint8_t registerAddress) const {
+  ControlByte control;
+  control.registerAddress = registerAddress;
+  control.rw = 1;
+
+  spi_->beginTransaction(spiSettings_);
+  digitalWrite(csPin_, LOW);
+
+  spi_->transfer(control.value);
+  uint8_t value = spi_->transfer(0);
+
+  digitalWrite(csPin_, HIGH);
+  spi_->endTransaction();
+
+  return value;
+}
+
+uint16_t Bme280FourWire::read16(const uint8_t registerAddress) const {
+  ControlByte control;
+  control.registerAddress = registerAddress;
+  control.rw = 1;
+
+  spi_->beginTransaction(spiSettings_);
+  digitalWrite(csPin_, LOW);
+
+  spi_->transfer(control.value);
+  uint16_t value = (spi_->transfer(0) << 8) | spi_->transfer(0);
+
+  digitalWrite(csPin_, HIGH);
+  spi_->endTransaction();
+
+  return value;
+}
+
+uint32_t Bme280FourWire::read24(const uint8_t registerAddress) const {
+  ControlByte control;
+  control.registerAddress = registerAddress;
+  control.rw = 1;
+
+  spi_->beginTransaction(spiSettings_);
+  digitalWrite(csPin_, LOW);
+
+  spi_->transfer(control.value);
+  uint32_t value = spi_->transfer(0);
+  value <<= 8;
+  value |= spi_->transfer(0);
+  value <<= 8;
+  value |= spi_->transfer(0);
+
+  digitalWrite(csPin_, HIGH);
+  spi_->endTransaction();
+
+  return value;
+}