1-Square-Inch 20Msps Oscilloscope Designed Around a PIC32MZ MCU
Although he didn’t place first in Hackaday’s “Return of the Square Inch Project Challenge,” Mark Omo was a runner-up for his entry — a 1 in² Oscilloscope, which he designed around a Microchip PIC32MZ EF microcontroller that uses internal ADCs in an interleaved mode to gain a 20Msps sampling rate. Mark found he was able to achieve a bandwidth of 1MHz in his setup.
Beyond the PIC32MZ EF driving the 1″ x 1″ show, the o-scope features an Electronic Assembly Yellow OLED display (96 x 64), an Analog Devices triple SPDT analog switch, and a TI TLV3541 100MHz rail-to-rail op amp. Finally, a great use for those tiny screens! I used a slightly larger one for a three-finger ring, check it out here.
Powering the o-scope is done via micro USB, and signals through an SMA connector located on the back of the PCB. There are six buttons — three on each side that allows you to set your trigger level, timescale, cycle through gain settings, and select between free-running and one-shot modes.
For those that want to recreate the tiny o-scope, or put your spin on his design, Omo has uploaded all of the open source hardware schematics, Altium, and Gerber files, along with the firmware to his GitHub page. While it doesn’t offer the same features and signal voltage range as more extensive, and more advanced scopes, it looks like it can come in handy as a shop tool you could use to get necessary signal data on-the-fly.