Radon Meter Hangs Randomly


The radon meter replacement board I have been working on is experiencing an intermittent problem where it seems to lock up and stop responding. I have taken many guesses at where the problem may lie in my code but finally I caved and asked for help on the esp8266 subreddit. There I received 2 suggestions for why the radon meter is crashing and not recovering.

The first suggestion was that the power may be browning out, and the second is that my I2C bus pullup resistors are not in range.

The second guess sounds the most likely to me. That is because I simply guessed that 10K would be a suitable value for the pullup resistors and since the display initially worked with this value I left it, but after reading some more literature on this matter it seems that since I’m using such a high data rate (800kbit according to the documentation) I should use a much lower value resistor. I desoldered the display and swapped the 10K resistors for 3.3K resistors today. Let’s see if this fixes the crashing.

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