I2C I/O Expander PCF8574 hanging?
Has anyone ever experienced problems with a PCF8574 hanging or blocking the I2C bus?
On one of my dataloggers I found that there had no data been logged for a number of days.
Due to the large number of Digital Inputs I have to deal with there is a number of PCF8574S on Board.
When I checked the system the PIC itself was running fine.
No Watchdog or Brownout Reset had occured during the period of time where data shold have been, but wasn't logged.
(There would have been a log entry, the RTC and Log-Memory are on a separate I2C-Bus)
I flipped some Inputs (which should have caused Log entries) but nothing happened.
(apart from the fact that the PIC responded to requests via RS232)
After a Powercyle everything was fine again.
To me it looks like the PCF8574 was hanging and required a Power OFF and ON.
regards
Ralph
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