st-anything/lib/Adafruit_BusIO/Adafruit_I2CDevice.cpp

185 lines
5.4 KiB
C++
Raw Normal View History

2023-03-11 14:11:03 +00:00
#include <Adafruit_I2CDevice.h>
#include <Arduino.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;
}
/*!
* @brief Initializes and does basic address detection
* @return True if I2C initialized and a device with the addr found
*/
bool Adafruit_I2CDevice::begin(void) {
_wire->begin();
_begun = true;
return detected();
}
/*!
* @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) {
return true;
}
return false;
}
/*!
* @brief Write a buffer or two to the I2C device. Cannot be more than 32 bytes.
* @param buffer Pointer to buffer of data to write
* @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 32 bytes.
* @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(uint8_t *buffer, size_t len, bool stop, uint8_t *prefix_buffer, size_t prefix_len) {
if ((len+prefix_len) > 32) {
// 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 != NULL)) {
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("\tI2CDevice Wrote: "));
if ((prefix_len != 0) && (prefix_buffer != NULL)) {
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 (len % 32 == 31) {
DEBUG_SERIAL.println();
}
}
DEBUG_SERIAL.println();
#endif
return (_wire -> endTransmission(stop) == 0);
}
/*!
* @brief Read from I2C into a buffer from the I2C device. Cannot be more than 32 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) {
if (len > 32) {
// 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 read such a large buffer"));
#endif
return false;
}
if (_wire->requestFrom((uint8_t)_addr, (uint8_t)len, (uint8_t)stop) != len) {
// Not enough data available to fulfill our obligation!
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("\tI2CDevice did not receive enough data"));
#endif
return false;
}
for (uint16_t i=0; i<len; i++) {
buffer[i] = _wire->read();
}
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tI2CDevice Read: "));
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 32 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(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;
}