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handler platforms with much larger i2c buffers

This commit is contained in:
ladyada 2019-10-20 01:53:07 -04:00
parent 5a5f8d0999
commit 4a419dc86f
2 changed files with 23 additions and 9 deletions
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27
Adafruit_I2CDevice.cpp
View File

@ -12,6 +12,11 @@ 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
#else
_maxBufferSize = 32;
#endif
}
/*!
@ -51,16 +56,17 @@ bool Adafruit_I2CDevice::detected(void) {
}
/*!
* @brief Write a buffer or two to the I2C device. Cannot be more than 32 bytes.
* @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
* @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_buffer Pointer to optional array of data to write before buffer.
* Cannot be more than maxBufferSize() 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) {
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 :/
@ -129,14 +135,15 @@ bool Adafruit_I2CDevice::write(uint8_t *buffer, size_t len, bool stop, uint8_t *
/*!
* @brief Read from I2C into a buffer from the I2C device. Cannot be more than 32 bytes.
* @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) {
if (len > 32) {
if (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 :/
@ -146,10 +153,12 @@ bool Adafruit_I2CDevice::read(uint8_t *buffer, size_t len, bool stop) {
return false;
}
if (_wire->requestFrom((uint8_t)_addr, (uint8_t)len, (uint8_t)stop) != len) {
size_t recv = _wire->requestFrom((uint8_t)_addr, (uint8_t)len, (uint8_t)stop);
if (recv != len) {
// Not enough data available to fulfill our obligation!
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.println(F("\tI2CDevice did not receive enough data"));
DEBUG_SERIAL.print(F("\tI2CDevice did not receive enough data: "));
DEBUG_SERIAL.println(recv);
#endif
return false;
}
@ -176,7 +185,9 @@ bool Adafruit_I2CDevice::read(uint8_t *buffer, size_t len, bool stop) {
/*!
* @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.
* @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.

5
Adafruit_I2CDevice.h
View File

@ -15,12 +15,15 @@ class Adafruit_I2CDevice {
bool write(uint8_t *buffer, size_t len, bool stop=true, uint8_t *prefix_buffer=NULL, size_t prefix_len=0);
bool write_then_read(uint8_t *write_buffer, size_t write_len, uint8_t *read_buffer, size_t read_len, bool stop=false);
/*! @brief How many bytes we can read in a transaction
* @return The size of the Wire receive/transmit buffer */
uint16_t maxBufferSize() { return _maxBufferSize; }
private:
uint8_t _addr;
TwoWire *_wire;
bool _begun;
uint16_t _maxBufferSize;
};
#endif // Adafruit_I2CDevice_h