You are reading a single comment by @heimi and its replies.
Click here to read the full conversation.
Espruino is a JavaScript interpreter for low-power Microcontrollers. This site is both a support community for Espruino and a place to share what you are working on.
@heimi
I'd like to point out, that if you plan to use a DS18B20 (sic, might as well be true for a 1820 or 18S20) in a real two wire mode with a parasite power pullup, than the module won't work. You'll end up reading the power up values for the temperature bytes (0x50, 0x05) instead of real values. By looking in the Arduino code I found that the code simply waits if a parasite mode is detected. This has to be implemented. The time to wait depends on the resolution, so please refer to the data sheet.
As a workaround you may just want to delay up to one second (750ms is max conversion time if 12 bit resolution is used), after the CONVERT_T (0x44) command was issued. This usecase is also documented in the date sheet (convert t command)