MiniR4_I2CDevice.cpp

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/*
The MIT License (MIT)
 
Copyright (c) 2017 Adafruit Industries
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#include "MiniR4_I2CDevice.h"
 
//#define DEBUG_SERIAL Serial
 
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
}
 
bool Adafruit_I2CDevice::begin(bool addr_detect) {
  _wire->begin();
  _begun = true;
 
  if (addr_detect) {
    return detected();
  }
  return true;
}
 
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
}
 
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);
#ifdef DEBUG_SERIAL
  DEBUG_SERIAL.print(F("Address 0x"));
  DEBUG_SERIAL.print(_addr);
#endif
  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;
}
 
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;
  }
}
 
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;
}
 
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);
}
 
uint8_t Adafruit_I2CDevice::address(void) { return _addr; }
 
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
}