Hex Logic Detector with AVR128DB28

Abstract

Purpose: Detection of logic levels or pulses

MCU: Microchips' AVR128DB28

Power: Powered by the circuit to be tested. (This ensures that logic leves are compatible.)

PCB layout: None. Use perfboard and point-to-point wiring.

Firmware platform: Arduino IDE w/ DxCore

Six logic channels.
Logic levels: Low, high, or floating displayed by red and green LEDs
Edge detection: Blue LEDs flash when level changes
Channels 2, 3, 4 & 5 detect pulses as short as 25 ns. (Channels 0 & 1: 50 ns)
Supply voltage span: 2.5 to 5.0 V (U_B - MCU and channels 3, 4 & 5)
Three channels can optionally operate at different voltage: 1.65 to 5.0 V (U_A - channels 0, 1 & 2)
System resets when primary supply voltage is too low (U_B < 2.45 V)
Indicator for insufficient secondary supply voltage (U_A < 1.65 V)