When I connect a DIgistump (ATTiny85 breakout board) to my PCs USB it connects and stays on. If I do the same with a Digispark Pro (ATTiny167) it connects and disconnects after 3 seconds.
When I try to upload a sketch I get “avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)”. Since ATTiny167 runs Micronucleus as bootloader it should prompt for a device. It is impossible to connect the ATTiny just in time for the uploader to detect it.
I changed to digispark-pro and had to delete a few built libraries but it works now. The reason I jumped over to the ATTiny167 was to see if the problem with the OLED display showing 25 degrees for both sensors would show here and it still does. The problem has nothing to do with the esp32 where I first saw the problem… I’ve been thinking if it has something to do with conversion from float to char*. If I bricked the sensors they would probably show nothing or something other than 25.
Do you have a cheap logic analyzer? Salae logic analyzer clones are just ~10€ (e.g. “AZDelivery Logic Analyzer 8 CH”), you can plug them into the OneWire bus and see the data. Then there’s no guessing around on what conversion went wrong, if the logic decoder shows that the sensor sends the data for “25.0°C”, then the fault is localized exactly there.
OK, I just ordered a AZDelivery Logic Analyzer 8 CH and it’ll arrive in a few days. In the meantime I downloaded Saleae Logic Analyzer version 1.2.18. Looked like it was free and I hope it’s the right version.