The brains of the operation is an STM8S103F module, aka the Blue Pill, which is paired with a DS18B20 temperature sensor. [Tim]’s original coaster has one in a TO-92 package embedded in the top ...

such as “1,” “I” (uppercase i), and “l” (lower case L). Always compare the pill in hand with the image in the Pill Identifier results to confirm that they match, even if the Pill ...

He decided to build his own, and documented his results in an 8 part tutorial. He’s using the Blue Pill board and the resulting device sends code with paddles, sends canned text, provides an LCD ...