Pseudonymous maker “gokux” has designed a provider board that turns a Seeed Studio XIAO SAMD21 board right into a six-channel 0-18V voltmeter with on-board OLED show — powered from a USB Kind-C connector.
“Some particular functions usually need to measure the voltage from a number of components on the similar time,” gokux explains of the rationale for a multi-channel machine for studying differing voltages. “For instance electronics restore, scientific, and experimental functions. In the event you’re constructing a battery pack it might additionally present the voltage of every cell concurrently.”
A compact provider board, a show, and some resistors flip a Seeed XIAO into an 18V voltmeter. (📷: gokux)
Quite than choosing one thing up off-the-shelf, although, gokux determined to construct a voltmeter of their very own — taking, as its base, the compact Seeed Studio XIAO SAMD21 growth board. To this, gokux added a 0.91″ 128×32 OLED, a handful of resistors, and headers for ease of connecting to the machine on check, all mounted in a custom-designed provider board.
“[The] XIAO solely can measure the voltage as much as 3.3V,” gokux explains of the resistors’ function. “Greater than that can harm the MCU [Microcontroller Unit], so we have to use a voltage divider for that. Because the identify suggests, a voltage divider will assist us to divide larger voltage into smaller voltage which could be measured utilizing [the] XIAO. We’re utilizing 100k and 22k resistors to construct our voltage divider; with this we are able to measure [from] 0V to 18V. Greater than this restrict will fry your MCU.”
The total challenge write-up is on Hackaday.io, with schematics and Gerbers for individuals who need to construct their very own.