Inexpensive compact carrier board turns the Seeed XIAO SAMD21 into a six-channel 18V voltmeter
2024-02-21 12:48
Pseudonymous manufacturer "Gokux" has developed a carrier board that turns the Seeed Studio XIAO SAMD21 board into a six-channel 0-18V voltmeter with an OLED display on board powered by a USB Type-C connector.
"It is often necessary to measure voltages on several parts at the same time," explains Gokux the reason for needing a multi-channel device to read different voltages. "For example for electronics repair, scientific and experimental purposes."
Gokux created his own voltmeter by taking the Seeed Studio XIAO SAMD21 compact development board. To it, Gokux added a 0.91-inch 128×32 OLED display, several resistors and connectors for easy connection to the device under test, all mounted on a custom-designed board.
"The XIAO only measures voltage up to 3.3V," Gokux explains the purpose of the resistors. A higher voltage could damage the MCU (microcontroller unit). So we use a voltage divider" - 100k and 22k resistors - to measure voltages from 0 to 18V. Exceeding this limit will cause the MCU to fail".