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Reducing excessive I2C timeout #494

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Reducing excessive I2C timeout #494

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265d24c
Reducing excessive I2C communication timeout (added however the possi…
maidnl Sep 23, 2025
bb58da9
Added short comment on function
maidnl Sep 23, 2025
4f15d9d
Renamed Wire timeout function
maidnl Sep 24, 2025
1e3a547
Updated setWireTimeout function signature to be compliant with same f…
maidnl Oct 13, 2025
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19 changes: 12 additions & 7 deletions libraries/Wire/Wire.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -465,7 +465,7 @@ void TwoWire::end(void) {


/* -------------------------------------------------------------------------- */
uint8_t TwoWire::read_from(uint8_t address, uint8_t* data, uint8_t length, unsigned int timeout_ms, bool sendStop) {
uint8_t TwoWire::read_from(uint8_t address, uint8_t* data, uint8_t length, unsigned int timeout_us, bool sendStop) {
/* -------------------------------------------------------------------------- */
/* ??? does this function make sense only for MASTER ???? */

Expand All @@ -480,8 +480,8 @@ uint8_t TwoWire::read_from(uint8_t address, uint8_t* data, uint8_t length, unsig
err = m_read(&m_i2c_ctrl,data,length,!sendStop);
}
}
uint32_t const start = millis();
while(((millis() - start) < timeout_ms) && bus_status == WIRE_STATUS_UNSET && err == FSP_SUCCESS) {
uint32_t const start = micros();
while(((micros() - start) < timeout_us) && bus_status == WIRE_STATUS_UNSET && err == FSP_SUCCESS) {

}
}
Expand All @@ -494,7 +494,7 @@ uint8_t TwoWire::read_from(uint8_t address, uint8_t* data, uint8_t length, unsig
}

/* -------------------------------------------------------------------------- */
uint8_t TwoWire::write_to(uint8_t address, uint8_t* data, uint8_t length, unsigned int timeout_ms, bool sendStop) {
uint8_t TwoWire::write_to(uint8_t address, uint8_t* data, uint8_t length, unsigned int timeout_us, bool sendStop) {
/* -------------------------------------------------------------------------- */
uint8_t rv = END_TX_OK;
fsp_err_t err = FSP_ERR_ASSERTION;
Expand All @@ -508,8 +508,8 @@ uint8_t TwoWire::write_to(uint8_t address, uint8_t* data, uint8_t length, unsign
err = m_write(&m_i2c_ctrl,data,length,!sendStop);
}
}
uint32_t const start = millis();
while(((millis() - start) < timeout_ms) && bus_status == WIRE_STATUS_UNSET && err == FSP_SUCCESS) {
uint32_t const start = micros();
while(((micros() - start) < timeout_us) && bus_status == WIRE_STATUS_UNSET && err == FSP_SUCCESS) {

}

Expand Down Expand Up @@ -835,7 +835,12 @@ void TwoWire::flush(void) {
while(bus_status != WIRE_STATUS_TX_COMPLETED && bus_status != WIRE_STATUS_TRANSACTION_ABORTED) {}
}


/* -------------------------------------------------------------------------- */
void TwoWire::setWireTimeout(unsigned int t, bool reset_on_timeout) {
/* -------------------------------------------------------------------------- */
(void)reset_on_timeout;
timeout = t;
}


#if WIRE_HOWMANY > 0
Expand Down
3 changes: 3 additions & 0 deletions libraries/Wire/Wire.h
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Original file line number Diff line number Diff line change
Expand Up @@ -124,6 +124,9 @@ class TwoWire : public arduino::HardwareI2C {
void onRequest( void (*)(void) );

void setBusStatus(WireStatus_t);
/* set timeout in us for I2C communication (default is 1000 us)
the second parameter has been added for compatibility but it has no effect*/
void setWireTimeout(unsigned int t = 25000, bool reset_on_timeout = false);

inline size_t write(unsigned long n) { return write((uint8_t)n); }
inline size_t write(long n) { return write((uint8_t)n); }
Expand Down