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greiman / SSD1306Ascii

Text only Arduino Library for SSD1306 OLED displays
MIT License
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Atmega328PB SSD1306AsciiAvrI2c issues #78

Closed ZL1CVD closed 3 years ago

ZL1CVD commented 3 years ago

FYI - some end user feedback for you.

I have had huge stability problems when using SSD1306AsciiAvrI2c.h

Display starts then randomly everything locks up. Tried a wide range of speeds using oled.setI2cClock which did prove some speeds withing a range worked better than others.

Changed code to use Wire SSD1306AsciiWire.h and all issues resolved EXCEPT now have low memory. But it does work.

greiman commented 3 years ago

Wire has lots of timeouts and resets so it tends not to hang with marginal devices. There are two places in AvrI2c that could hang and I plan to add a timeout and reset to these. Unfortunately I don't have a marginal device to verify the fix.

I suspect most most devices hang on an I2C stop so a reset probably would cause limited glitches since it may occur after all data is sent to the device.

I am currently using AvrI2c in a minimal size RTC library so maybe I will find a marginal RTC chip.

greiman commented 3 years ago

I replace AvrI2c.h with one that has time-outs and some other mods. It shouldn't hang in a loop waiting for an I2C command to complete.

If there are glitches in the display we can pursue these. Debug prints can be enabled in AvrI2c.h at about line 78.

I did some experiments an found a hang was possible if the I2C bus didn't have pull-ups.

ZL1CVD commented 3 years ago

Thank you. Stability issue resolved. I have not managed to lock up even once. Now compiled code is bigger than Arduino IVR even with LTO enabled. This no longer such an issue for me as I reduced serial TX/RX buffer size to accommodate arduino wire code.