ESP32 Electrolysis PCB Design -- 2
Budget / SalaryA$250–750
TypeFreelance project
LocationRemote
Posted1 hour ago
I’m building a compact electrolysis hair-removal unit and need a full schematic and PCB layout that an assembler can take straight to production.
Core requirements
• Control core: ESP32 must set DC current (0–5 mA) and RF power (up to 2 W at 13.56 MHz). USB-C power would be nice, but 20v PD might not be enough voltage so lets have a 24v barrel jack input too. Hard cap current limit for these rails, the power supply must be physically unable to supply more for safety.
• RF power should be adjusted by use of PWM on an RF fet to reduce the effective power.
• Dual-path power: DC and RF run independently yet may operate simultaneously. The RF path travels down the probe needle, which is the DC low-side return. A bias-tee approach seems most practical to me (though I'm not that experienced with RF); I’m open to alternative RF/DC combining networks as well.
• High-side connection: the positive DC terminal links to a metal plate the user sits on. If a negative-rail design is easier, I’m fine with the chassis gnd acting as the high side.
• Remote control: adjustments are made from a smartphone app (Bluetooth LE or Wi-Fi—your choice), or via onboard buttons. - see image https://www.sterex.com/wp-content/uploads/2020/01/SX-B-Aerial-View-NEW-2025-web.png
• Feedback: the app must display real-time voltage and current readings pulled from the ESP32’s ADCs or dedicated sensing ICs. to set the current accurately, the ESP should measure the resistance between needle and return, and set the voltage based on ohms law for the target current.
Deliverables
1. Complete schematic in KiCad or Altium, including bias-tee, RF filter/matching network, isolated sensing, and ESP32 support circuitry. ideally I'd like each part modular i.e psu board, RF generation, control board, DC regulation etc so these can be tested independently and makes touch ups later easy. - mezzanine or IDC ribbon linked linked board are OK. - RF/DC out via centre pin of a BNC connector. indifferent plate/DC high side is via a chassis mounted banana plug. foot pedal via 3.5mm mono jack.
2. Two-layer (or more, if RF integrity demands) PCB layout ready for Gerber fabrication, plus an annotated BOM with ordering links. - 2 layer preferred if we can. Happy to prototype with through hole parts if it's simple enough. - this will allow for changes down the line.
3. Reference firmware that exposes all of the data points collected and allows simple setting.
4. Design notes explaining component choices, RF considerations, and safe operating limits.
I value clean RF design, proper grounding, and parts that are readily available. If you’ve built RF-mixed or electro-medical boards before, let me know, proof of similar work is a big plus.
Competitors product is:
https://www.sterex.com/product/sterex-blend-electrolysis-machine-sx-b-blend/
Core requirements
• Control core: ESP32 must set DC current (0–5 mA) and RF power (up to 2 W at 13.56 MHz). USB-C power would be nice, but 20v PD might not be enough voltage so lets have a 24v barrel jack input too. Hard cap current limit for these rails, the power supply must be physically unable to supply more for safety.
• RF power should be adjusted by use of PWM on an RF fet to reduce the effective power.
• Dual-path power: DC and RF run independently yet may operate simultaneously. The RF path travels down the probe needle, which is the DC low-side return. A bias-tee approach seems most practical to me (though I'm not that experienced with RF); I’m open to alternative RF/DC combining networks as well.
• High-side connection: the positive DC terminal links to a metal plate the user sits on. If a negative-rail design is easier, I’m fine with the chassis gnd acting as the high side.
• Remote control: adjustments are made from a smartphone app (Bluetooth LE or Wi-Fi—your choice), or via onboard buttons. - see image https://www.sterex.com/wp-content/uploads/2020/01/SX-B-Aerial-View-NEW-2025-web.png
• Feedback: the app must display real-time voltage and current readings pulled from the ESP32’s ADCs or dedicated sensing ICs. to set the current accurately, the ESP should measure the resistance between needle and return, and set the voltage based on ohms law for the target current.
Deliverables
1. Complete schematic in KiCad or Altium, including bias-tee, RF filter/matching network, isolated sensing, and ESP32 support circuitry. ideally I'd like each part modular i.e psu board, RF generation, control board, DC regulation etc so these can be tested independently and makes touch ups later easy. - mezzanine or IDC ribbon linked linked board are OK. - RF/DC out via centre pin of a BNC connector. indifferent plate/DC high side is via a chassis mounted banana plug. foot pedal via 3.5mm mono jack.
2. Two-layer (or more, if RF integrity demands) PCB layout ready for Gerber fabrication, plus an annotated BOM with ordering links. - 2 layer preferred if we can. Happy to prototype with through hole parts if it's simple enough. - this will allow for changes down the line.
3. Reference firmware that exposes all of the data points collected and allows simple setting.
4. Design notes explaining component choices, RF considerations, and safe operating limits.
I value clean RF design, proper grounding, and parts that are readily available. If you’ve built RF-mixed or electro-medical boards before, let me know, proof of similar work is a big plus.
Competitors product is:
https://www.sterex.com/product/sterex-blend-electrolysis-machine-sx-b-blend/
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