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Merge pull request #97 from caternuson/iss23_busio
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Convert to BusIO
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@caternuson
caternuson authored Jul 31, 2021
2 parents 0c4398f + dba3ce0 commit 587329a
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Showing 3 changed files with 52 additions and 144 deletions.
178 changes: 46 additions & 132 deletions Adafruit_BME280.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -30,13 +30,11 @@

#include "Adafruit_BME280.h"
#include "Arduino.h"
#include <SPI.h>
#include <Wire.h>

/*!
* @brief class constructor
*/
Adafruit_BME280::Adafruit_BME280() : _cs(-1), _mosi(-1), _miso(-1), _sck(-1) {}
Adafruit_BME280::Adafruit_BME280() {}

/*!
* @brief class constructor if using hardware SPI
Expand All @@ -45,9 +43,8 @@ Adafruit_BME280::Adafruit_BME280() : _cs(-1), _mosi(-1), _miso(-1), _sck(-1) {}
* optional SPI object
*/
Adafruit_BME280::Adafruit_BME280(int8_t cspin, SPIClass *theSPI) {
_cs = cspin;
_mosi = _miso = _sck = -1;
_spi = theSPI;
spi_dev = new Adafruit_SPIDevice(cspin, 1000000, SPI_BITORDER_MSBFIRST,
SPI_MODE0, theSPI);
}

/*!
Expand All @@ -58,8 +55,9 @@ Adafruit_BME280::Adafruit_BME280(int8_t cspin, SPIClass *theSPI) {
* @param sckpin the SCK pin to use
*/
Adafruit_BME280::Adafruit_BME280(int8_t cspin, int8_t mosipin, int8_t misopin,
int8_t sckpin)
: _cs(cspin), _mosi(mosipin), _miso(misopin), _sck(sckpin) {}
int8_t sckpin) {
spi_dev = new Adafruit_SPIDevice(cspin, sckpin, misopin, mosipin);
}

Adafruit_BME280::~Adafruit_BME280(void) {
if (temp_sensor) {
Expand All @@ -80,37 +78,22 @@ Adafruit_BME280::~Adafruit_BME280(void) {
* @returns true on success, false otherwise
*/
bool Adafruit_BME280::begin(uint8_t addr, TwoWire *theWire) {
bool status = false;
_i2caddr = addr;
_wire = theWire;
status = init();

return status;
if (spi_dev == NULL) {
i2c_dev = new Adafruit_I2CDevice(addr, theWire);
if (!i2c_dev->begin())
return false;
} else {
if (!spi_dev->begin())
return false;
}
return init();
}

/*!
* @brief Initialise sensor with given parameters / settings
* @returns true on success, false otherwise
*/
bool Adafruit_BME280::init() {
// init I2C or SPI sensor interface
if (_cs == -1) {
// I2C
_wire->begin();
} else {
digitalWrite(_cs, HIGH);
pinMode(_cs, OUTPUT);
if (_sck == -1) {
// hardware SPI
_spi->begin();
} else {
// software SPI
pinMode(_sck, OUTPUT);
pinMode(_mosi, OUTPUT);
pinMode(_miso, INPUT);
}
}

// check if sensor, i.e. the chip ID is correct
_sensorID = read8(BME280_REGISTER_CHIPID);
if (_sensorID != 0x60)
Expand Down Expand Up @@ -175,50 +158,20 @@ void Adafruit_BME280::setSampling(sensor_mode mode,
write8(BME280_REGISTER_CONTROL, _measReg.get());
}

/*!
* @brief Encapsulate hardware and software SPI transfer into one
* function
* @param x the data byte to transfer
* @returns the data byte read from the device
*/
uint8_t Adafruit_BME280::spixfer(uint8_t x) {
// hardware SPI
if (_sck == -1)
return _spi->transfer(x);

// software SPI
uint8_t reply = 0;
for (int i = 7; i >= 0; i--) {
reply <<= 1;
digitalWrite(_sck, LOW);
digitalWrite(_mosi, x & (1 << i));
digitalWrite(_sck, HIGH);
if (digitalRead(_miso))
reply |= 1;
}
return reply;
}

/*!
* @brief Writes an 8 bit value over I2C or SPI
* @param reg the register address to write to
* @param value the value to write to the register
*/
void Adafruit_BME280::write8(byte reg, byte value) {
if (_cs == -1) {
_wire->beginTransmission((uint8_t)_i2caddr);
_wire->write((uint8_t)reg);
_wire->write((uint8_t)value);
_wire->endTransmission();
byte buffer[2];
buffer[1] = value;
if (i2c_dev) {
buffer[0] = reg;
i2c_dev->write(buffer, 2);
} else {
if (_sck == -1)
_spi->beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
digitalWrite(_cs, LOW);
spixfer(reg & ~0x80); // write, bit 7 low
spixfer(value);
digitalWrite(_cs, HIGH);
if (_sck == -1)
_spi->endTransaction(); // release the SPI bus
buffer[0] = reg & ~0x80;
spi_dev->write(buffer, 2);
}
}

Expand All @@ -228,25 +181,15 @@ void Adafruit_BME280::write8(byte reg, byte value) {
* @returns the data byte read from the device
*/
uint8_t Adafruit_BME280::read8(byte reg) {
uint8_t value;

if (_cs == -1) {
_wire->beginTransmission((uint8_t)_i2caddr);
_wire->write((uint8_t)reg);
_wire->endTransmission();
_wire->requestFrom((uint8_t)_i2caddr, (byte)1);
value = _wire->read();
uint8_t buffer[1];
if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 1);
} else {
if (_sck == -1)
_spi->beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
digitalWrite(_cs, LOW);
spixfer(reg | 0x80); // read, bit 7 high
value = spixfer(0);
digitalWrite(_cs, HIGH);
if (_sck == -1)
_spi->endTransaction(); // release the SPI bus
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 1);
}
return value;
return buffer[0];
}

/*!
Expand All @@ -255,26 +198,16 @@ uint8_t Adafruit_BME280::read8(byte reg) {
* @returns the 16 bit data value read from the device
*/
uint16_t Adafruit_BME280::read16(byte reg) {
uint16_t value;

if (_cs == -1) {
_wire->beginTransmission((uint8_t)_i2caddr);
_wire->write((uint8_t)reg);
_wire->endTransmission();
_wire->requestFrom((uint8_t)_i2caddr, (byte)2);
value = (_wire->read() << 8) | _wire->read();
uint8_t buffer[2];

if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 2);
} else {
if (_sck == -1)
_spi->beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
digitalWrite(_cs, LOW);
spixfer(reg | 0x80); // read, bit 7 high
value = (spixfer(0) << 8) | spixfer(0);
digitalWrite(_cs, HIGH);
if (_sck == -1)
_spi->endTransaction(); // release the SPI bus
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 2);
}

return value;
return uint16_t(buffer[0]) << 8 | uint16_t(buffer[1]);
}

/*!
Expand Down Expand Up @@ -309,37 +242,18 @@ int16_t Adafruit_BME280::readS16_LE(byte reg) {
* @returns the 24 bit data value read from the device
*/
uint32_t Adafruit_BME280::read24(byte reg) {
uint32_t value;

if (_cs == -1) {
_wire->beginTransmission((uint8_t)_i2caddr);
_wire->write((uint8_t)reg);
_wire->endTransmission();
_wire->requestFrom((uint8_t)_i2caddr, (byte)3);

value = _wire->read();
value <<= 8;
value |= _wire->read();
value <<= 8;
value |= _wire->read();
uint8_t buffer[3];

if (i2c_dev) {
buffer[0] = uint8_t(reg);
i2c_dev->write_then_read(buffer, 1, buffer, 3);
} else {
if (_sck == -1)
_spi->beginTransaction(SPISettings(500000, MSBFIRST, SPI_MODE0));
digitalWrite(_cs, LOW);
spixfer(reg | 0x80); // read, bit 7 high

value = spixfer(0);
value <<= 8;
value |= spixfer(0);
value <<= 8;
value |= spixfer(0);

digitalWrite(_cs, HIGH);
if (_sck == -1)
_spi->endTransaction(); // release the SPI bus
buffer[0] = uint8_t(reg | 0x80);
spi_dev->write_then_read(buffer, 1, buffer, 3);
}

return value;
return uint32_t(buffer[0]) << 16 | uint32_t(buffer[1]) << 8 |
uint32_t(buffer[2]);
}

/*!
Expand Down
14 changes: 4 additions & 10 deletions Adafruit_BME280.h
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Original file line number Diff line number Diff line change
Expand Up @@ -23,9 +23,9 @@

#include "Arduino.h"

#include <Adafruit_I2CDevice.h>
#include <Adafruit_SPIDevice.h>
#include <Adafruit_Sensor.h>
#include <SPI.h>
#include <Wire.h>

/*!
* @brief default I2C address
Expand Down Expand Up @@ -242,8 +242,8 @@ class Adafruit_BME280 {
Adafruit_Sensor *getHumiditySensor(void);

protected:
TwoWire *_wire; //!< pointer to a TwoWire object
SPIClass *_spi; //!< pointer to SPI object
Adafruit_I2CDevice *i2c_dev = NULL; ///< Pointer to I2C bus interface
Adafruit_SPIDevice *spi_dev = NULL; ///< Pointer to SPI bus interface

Adafruit_BME280_Temp *temp_sensor = NULL;
//!< Adafruit_Sensor compat temperature sensor component
Expand All @@ -256,7 +256,6 @@ class Adafruit_BME280 {

void readCoefficients(void);
bool isReadingCalibration(void);
uint8_t spixfer(uint8_t x);

void write8(byte reg, byte value);
uint8_t read8(byte reg);
Expand All @@ -272,11 +271,6 @@ class Adafruit_BME280 {
//!< as this is used for temperature compensation reading
//!< humidity and pressure

int8_t _cs; //!< for the SPI interface
int8_t _mosi; //!< for the SPI interface
int8_t _miso; //!< for the SPI interface
int8_t _sck; //!< for the SPI interface

int32_t t_fine_adjust = 0; //!< add to compensate temp readings and in turn
//!< to pressure and humidity readings

Expand Down
4 changes: 2 additions & 2 deletions library.properties
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Original file line number Diff line number Diff line change
@@ -1,10 +1,10 @@
name=Adafruit BME280 Library
version=2.1.4
version=2.2.0
author=Adafruit
maintainer=Adafruit <[email protected]>
sentence=Arduino library for BME280 sensors.
paragraph=Arduino library for BME280 humidity and pressure sensors.
category=Sensors
url=https://github.com/adafruit/Adafruit_BME280_Library
architectures=*
depends=Adafruit Unified Sensor
depends=Adafruit Unified Sensor, Adafruit BusIO

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