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Update I2CManager_NonBlocking.h

Add code to try and recover from stuck bus following a timeout.
This commit is contained in:
Neil McKechnie 2023-02-02 12:21:35 +00:00
parent ba9b363058
commit 49713badb2

View File

@ -213,10 +213,21 @@ void I2CManagerClass::checkForTimeout() {
// Reset TWI interface so it is able to continue
// Try close and init, not entirely satisfactory but sort of works...
I2C_close(); // Shutdown and restart twi interface
// If SDA is stuck low, issue up to 9 clock pulses to attempt to free it.
pinMode(SCL, INPUT_PULLUP);
pinMode(SDA, INPUT_PULLUP);
for (int i=0; !digitalRead(SDA) && i<9; i++) {
digitalWrite(SCL, 0);
pinMode(SCL, OUTPUT); // Force clock low
delayMicroseconds(10); // ... for 5us
pinMode(SCL, INPUT_PULLUP); // ... then high
delayMicroseconds(10); // ... for 5us (100kHz Clock)
}
// Whether that's succeeded or not, now try reinitialising.
I2C_init();
_setClock(_clockSpeed);
state = I2C_STATE_FREE;
// I2C_sendStop(); // in case device is waiting for a stop condition
// Initiate next queued request if any.
startTransaction();