A debug tool created by vibe-circuiting

Input:Design a all in one debugging tool that includes the following modules: an adjustable power supply with a 12V input and an output voltage ranging from 0 to 12V; a multimeter（requiring only voltage measurement, resistance measurement, and short-circuit testing）; a logic analyzer; and a PWM generator and a simple single-channel oscilloscope, using a small screen to display

Block diagram

Main function modules

Topology of multimeter

A grounded, non-isolated analog front end around a small local MCU:

• 3-pin screw terminal for DMM_NEG, DMM_POS, and SCOPE_IN
• Protected DMM path
• high-range divider for external voltage measurement
• direct low-range sense for resistance / continuity resolution
• switched stimulus sources for ohms and continuity
• Protected DMM pathhigh-range divider for external voltage measurementdirect low-range sense for resistance / continuity resolutionswitched stimulus sources for ohms and continuityProtected scope path
• fixed attenuator + RC bandwidth limit into MCU ADC
• Protected scope pathfixed attenuator + RC bandwidth limit into MCU ADC

Topology of adjustable power

Hybrid adjustable output:

• Buck path: 12V bus -> TPS54331 buck -> diode OR -> protected output node
• 12V bypass path: 12V bus -> P-MOSFET bypass -> protected output node
• Output protection: protected node -> TPS259470A eFuse -> screw terminal
• Control: small MCU on 3.3V handles enable, setpoint PWM, bypass selection, and fault/status

Topology of PWM generator

Local digital front-end built around an STM32G431:

• 8 protected logic-analyzer inputs
• 1 protected PWM output
• 1 shared 2x7 probe header with DGND returns
• 1-wire 3.3V management link to the control module

Input channels use 4.7k series resistance + ESD clamp + 100k pulldown + 74HC4050 buffering before the MCU.PWM uses a tri-state buffer that powers up disabled, with a weak pulldown so the external pin defaults inactive

The full project export to Kicad

Schematic export to PCB

These features are designed based on my personal debugging habits. If you’d like to design tools that fit your testing habits, give it a try