weatherstation/firmware/libraries/Adafruit_BusIO/Adafruit_I2CDevice.cpp
2022-11-11 11:11:25 +01:00

313 lines
9 KiB
C++

#include "Adafruit_I2CDevice.h"
//#define DEBUG_SERIAL Serial
/*!
* @brief Create an I2C device at a given address
* @param addr The 7-bit I2C address for the device
* @param theWire The I2C bus to use, defaults to &Wire
*/
Adafruit_I2CDevice::Adafruit_I2CDevice(uint8_t addr, TwoWire *theWire) {
_addr = addr;
_wire = theWire;
_begun = false;
#ifdef ARDUINO_ARCH_SAMD
_maxBufferSize = 250; // as defined in Wire.h's RingBuffer
#elif defined(ESP32)
_maxBufferSize = I2C_BUFFER_LENGTH;
#else
_maxBufferSize = 32;
#endif
}
/*!
* @brief Initializes and does basic address detection
* @param addr_detect Whether we should attempt to detect the I2C address
* with a scan. 99% of sensors/devices don't mind but once in a while, they spaz
* on a scan!
* @return True if I2C initialized and a device with the addr found
*/
bool Adafruit_I2CDevice::begin(bool addr_detect) {
_wire->begin();
_begun = true;
if (addr_detect) {
return detected();
}
return true;
}
/*!
* @brief De-initialize device, turn off the Wire interface
*/
void Adafruit_I2CDevice::end(void) {
// Not all port implement Wire::end(), such as
// - ESP8266
// - AVR core without WIRE_HAS_END
// - ESP32: end() is implemented since 2.0.1 which is latest at the moment.
// Temporarily disable for now to give time for user to update.
#if !(defined(ESP8266) || \
(defined(ARDUINO_ARCH_AVR) && !defined(WIRE_HAS_END)) || \
defined(ARDUINO_ARCH_ESP32))
_wire->end();
_begun = false;
#endif
}
/*!
* @brief Scans I2C for the address - note will give a false-positive
* if there's no pullups on I2C
* @return True if I2C initialized and a device with the addr found
*/
bool Adafruit_I2CDevice::detected(void) {
// Init I2C if not done yet
if (!_begun && !begin()) {
return false;
}
// A basic scanner, see if it ACK's
_wire->beginTransmission(_addr);
if (_wire->endTransmission() == 0) {
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("Detected"));
#endif
return true;
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("Not detected"));
#endif
return false;
}
/*!
* @brief Write a buffer or two to the I2C device. Cannot be more than
* maxBufferSize() bytes.
* @param buffer Pointer to buffer of data to write. This is const to
* ensure the content of this buffer doesn't change.
* @param len Number of bytes from buffer to write
* @param prefix_buffer Pointer to optional array of data to write before
* buffer. Cannot be more than maxBufferSize() bytes. This is const to
* ensure the content of this buffer doesn't change.
* @param prefix_len Number of bytes from prefix buffer to write
* @param stop Whether to send an I2C STOP signal on write
* @return True if write was successful, otherwise false.
*/
bool Adafruit_I2CDevice::write(const uint8_t *buffer, size_t len, bool stop,
const uint8_t *prefix_buffer,
size_t prefix_len) {
if ((len + prefix_len) > maxBufferSize()) {
// currently not guaranteed to work if more than 32 bytes!
// we will need to find out if some platforms have larger
// I2C buffer sizes :/
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("\tI2CDevice could not write such a large buffer"));
#endif
return false;
}
_wire->beginTransmission(_addr);
// Write the prefix data (usually an address)
if ((prefix_len != 0) && (prefix_buffer != nullptr)) {
if (_wire->write(prefix_buffer, prefix_len) != prefix_len) {
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("\tI2CDevice failed to write"));
#endif
return false;
}
}
// Write the data itself
if (_wire->write(buffer, len) != len) {
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("\tI2CDevice failed to write"));
#endif
return false;
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tI2CWRITE @ 0x"));
DEBUG_SERIAL.print(_addr, HEX);
DEBUG_SERIAL.print(F(" :: "));
if ((prefix_len != 0) && (prefix_buffer != nullptr)) {
for (uint16_t i = 0; i < prefix_len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(prefix_buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
}
}
for (uint16_t i = 0; i < len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (i % 32 == 31) {
DEBUG_SERIAL.println();
}
}
if (stop) {
DEBUG_SERIAL.print("\tSTOP");
}
#endif
if (_wire->endTransmission(stop) == 0) {
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println();
// DEBUG_SERIAL.println("Sent!");
#endif
return true;
} else {
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println("\tFailed to send!");
#endif
return false;
}
}
/*!
* @brief Read from I2C into a buffer from the I2C device.
* Cannot be more than maxBufferSize() bytes.
* @param buffer Pointer to buffer of data to read into
* @param len Number of bytes from buffer to read.
* @param stop Whether to send an I2C STOP signal on read
* @return True if read was successful, otherwise false.
*/
bool Adafruit_I2CDevice::read(uint8_t *buffer, size_t len, bool stop) {
size_t pos = 0;
while (pos < len) {
size_t read_len =
((len - pos) > maxBufferSize()) ? maxBufferSize() : (len - pos);
bool read_stop = (pos < (len - read_len)) ? false : stop;
if (!_read(buffer + pos, read_len, read_stop))
return false;
pos += read_len;
}
return true;
}
bool Adafruit_I2CDevice::_read(uint8_t *buffer, size_t len, bool stop) {
#if defined(TinyWireM_h)
size_t recv = _wire->requestFrom((uint8_t)_addr, (uint8_t)len);
#elif defined(ARDUINO_ARCH_MEGAAVR)
size_t recv = _wire->requestFrom(_addr, len, stop);
#else
size_t recv = _wire->requestFrom((uint8_t)_addr, (uint8_t)len, (uint8_t)stop);
#endif
if (recv != len) {
// Not enough data available to fulfill our obligation!
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tI2CDevice did not receive enough data: "));
DEBUG_SERIAL.println(recv);
#endif
return false;
}
for (uint16_t i = 0; i < len; i++) {
buffer[i] = _wire->read();
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tI2CREAD @ 0x"));
DEBUG_SERIAL.print(_addr, HEX);
DEBUG_SERIAL.print(F(" :: "));
for (uint16_t i = 0; i < len; i++) {
DEBUG_SERIAL.print(F("0x"));
DEBUG_SERIAL.print(buffer[i], HEX);
DEBUG_SERIAL.print(F(", "));
if (len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
return true;
}
/*!
* @brief Write some data, then read some data from I2C into another buffer.
* Cannot be more than maxBufferSize() bytes. The buffers can point to
* same/overlapping locations.
* @param write_buffer Pointer to buffer of data to write from
* @param write_len Number of bytes from buffer to write.
* @param read_buffer Pointer to buffer of data to read into.
* @param read_len Number of bytes from buffer to read.
* @param stop Whether to send an I2C STOP signal between the write and read
* @return True if write & read was successful, otherwise false.
*/
bool Adafruit_I2CDevice::write_then_read(const uint8_t *write_buffer,
size_t write_len, uint8_t *read_buffer,
size_t read_len, bool stop) {
if (!write(write_buffer, write_len, stop)) {
return false;
}
return read(read_buffer, read_len);
}
/*!
* @brief Returns the 7-bit address of this device
* @return The 7-bit address of this device
*/
uint8_t Adafruit_I2CDevice::address(void) { return _addr; }
/*!
* @brief Change the I2C clock speed to desired (relies on
* underlying Wire support!
* @param desiredclk The desired I2C SCL frequency
* @return True if this platform supports changing I2C speed.
* Not necessarily that the speed was achieved!
*/
bool Adafruit_I2CDevice::setSpeed(uint32_t desiredclk) {
#if defined(__AVR_ATmega328__) || \
defined(__AVR_ATmega328P__) // fix arduino core set clock
// calculate TWBR correctly
if ((F_CPU / 18) < desiredclk) {
#ifdef DEBUG_SERIAL
Serial.println(F("I2C.setSpeed too high."));
#endif
return false;
}
uint32_t atwbr = ((F_CPU / desiredclk) - 16) / 2;
if (atwbr > 16320) {
#ifdef DEBUG_SERIAL
Serial.println(F("I2C.setSpeed too low."));
#endif
return false;
}
if (atwbr <= 255) {
atwbr /= 1;
TWSR = 0x0;
} else if (atwbr <= 1020) {
atwbr /= 4;
TWSR = 0x1;
} else if (atwbr <= 4080) {
atwbr /= 16;
TWSR = 0x2;
} else { // if (atwbr <= 16320)
atwbr /= 64;
TWSR = 0x3;
}
TWBR = atwbr;
#ifdef DEBUG_SERIAL
Serial.print(F("TWSR prescaler = "));
Serial.println(pow(4, TWSR));
Serial.print(F("TWBR = "));
Serial.println(atwbr);
#endif
return true;
#elif (ARDUINO >= 157) && !defined(ARDUINO_STM32_FEATHER) && \
!defined(TinyWireM_h)
_wire->setClock(desiredclk);
return true;
#else
(void)desiredclk;
return false;
#endif
}