Introduce non compulsory Wire timeout

move timout handling into its own function

change timeout from milliseconds to microseconds

don't forget operating slave address or the bitrate when we reset because of a timeout

Co-Authored-By: Witold Markowski <witold.a.markowski@gmail.com>

fix delay datatype uint16_t --> uint32_t

Update libraries/Wire/src/utility/twi.c

fix mix up using TWBR instea of TWAR!

Co-Authored-By: Matthijs Kooijman <matthijs@stdin.nl>

Update libraries/Wire/src/utility/twi.c

fix 2nd TWBR/TWAR mixup

Co-Authored-By: Matthijs Kooijman <matthijs@stdin.nl>

twi_stop() should use the same timeout as everywhere else

all while loops are now protected by timeouts

Revert "twi_stop() should use the same timeout as everywhere else"

This reverts commit 68fe5f1dae1bb41183bb37eeda3fb453394a580c.

make timeout counter volatile

rename timeout function for improved clarity

- resetting the twi interface on timeouts is now optional
- timeouts in the ISR are no longer hardcoded and now obey the set timeout value
- a user-readable flag is now set whenever a timeout occurs
  - the user can clear this flag whenever they like

1 files changed, 28 insertions, 0 deletions

diff --git a/libraries/Wire/src/Wire.cpp b/libraries/Wire/src/Wire.cpp
index 58916ce..b446f9a 100644
--- a/libraries/Wire/src/Wire.cpp
+++ b/libraries/Wire/src/Wire.cpp
@@ -18,6 +18,7 @@
  
   Modified 2012 by Todd Krein (todd@krein.org) to implement repeated starts
   Modified 2017 by Chuck Todd (ctodd@cableone.net) to correct Unconfigured Slave Mode reboot
+  Modified 2020 by Greyson Christoforo (grey@christoforo.net) to implement timeouts
 */
 
 extern "C" {
@@ -86,6 +87,33 @@ void TwoWire::setClock(uint32_t clock)
   twi_setFrequency(clock);
 }
 
+/***
+ * Sets the TWI timeout.
+ *
+ * @param timeout a timeout value in microseconds, if zero then timeout checking is disabled
+ * @param reset_with_timeout if true then TWI interface will be automatically reset on timeout
+ *                           if false then TWI interface will not be reset on timeout
+ */
+void TwoWire::setWireTimeoutUs(uint32_t timeout, bool reset_with_timeout){
+  twi_setTimeoutInMicros(timeout, reset_with_timeout);
+}
+
+/***
+ * Returns the TWI timeout flag.
+ *
+ * @return true if timeout has occured
+ */
+bool TwoWire::getWireTimeoutFlag(void){
+  return(twi_manageTimeoutFlag(false));
+}
+
+/***
+ * Clears the TWI timeout flag.
+ */
+void TwoWire::clearWireTimeoutFlag(void){
+  twi_manageTimeoutFlag(true);
+}
+
 uint8_t TwoWire::requestFrom(uint8_t address, uint8_t quantity, uint32_t iaddress, uint8_t isize, uint8_t sendStop)
 {
   if (isize > 0) {