ESP32-S3 High-Frequency Tachometer
Budget: $250 – $750 USD
Help me solve something multiple freelancers havent been able to. I need a rock solid circuit that reads a pulse from a wire wrapped around a spark plug wire of a small engine, filters the noise, and sends a clean pulse to an esp32-s3. The pickup will be a single, insulated wire loosely wound around a spark-plug lead, the code can be very simple as this circuit is part of a bigger project but has to cleanly condition and count the high-frequency ignition pulses, translate them into RPM, and remain stable across the usual noise you see near an engine.
The unit will sit in its own enclosure rather than on a vehicle dashboard, so everything—from debouncing to display refresh—has to be self-contained and powered from a 5–12 V supply. Please assume the pulses can reach several kHz at high revs.
THIS MUST BE CREATED AND TESTED ON YOUR END, THEN SENT TO ME FOR VERIFICATION VIA BREADBOARD OR 1 OFF PCB CREATION. PROJECT IS NOT COMPLETE UNTIL I HAVE A WORKING EXAMPLE ON MY END BUT WILL NOT HAVE THE TIME TO BUILD CIRCUITS HERE UNTIL IT HAS BEEN PROVEN TO WORK ON YOUR END.
Deliverables:
• Schematic (or clear fritzing/EDA file) of the input conditioning network and any level shifting
• ESP32-S3 source code (Arduino or ESP-IDF) that measures RPM accurately from idle to redline
• Brief calibration instructions and a serial/USB debug output for validation
If you’ve already tackled inductive pickups or noisy high-frequency counting on the ESP32 family, that experience will help us move fast.
The unit will sit in its own enclosure rather than on a vehicle dashboard, so everything—from debouncing to display refresh—has to be self-contained and powered from a 5–12 V supply. Please assume the pulses can reach several kHz at high revs.
THIS MUST BE CREATED AND TESTED ON YOUR END, THEN SENT TO ME FOR VERIFICATION VIA BREADBOARD OR 1 OFF PCB CREATION. PROJECT IS NOT COMPLETE UNTIL I HAVE A WORKING EXAMPLE ON MY END BUT WILL NOT HAVE THE TIME TO BUILD CIRCUITS HERE UNTIL IT HAS BEEN PROVEN TO WORK ON YOUR END.
Deliverables:
• Schematic (or clear fritzing/EDA file) of the input conditioning network and any level shifting
• ESP32-S3 source code (Arduino or ESP-IDF) that measures RPM accurately from idle to redline
• Brief calibration instructions and a serial/USB debug output for validation
If you’ve already tackled inductive pickups or noisy high-frequency counting on the ESP32 family, that experience will help us move fast.