Hex Logic Generator with AVR128DB28

Abstract

Purpose: Generation of well-defined 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, each provided with a "trigger" button (TRIG)
Static levels. TRIG can either toggle the level or work as (debounced) momentary switch
Single pulses. A pulse is emitted when TRIG is pressed
Free-running square waves. TRIG sets start phase of each channel
Free-running pulse trains distributed over the channels, separated or overlapped
output levels displayed by red and green LEDs
Supply voltage (and logic level) span: 2.5 to 5.0 V (U_B - MCU and channels 3, 4 & 5)
Three channels can 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)