pH/EC Meter Prototype Completion

I already have the schematic, PCB layout, and BOM for a handheld pH / EC meter, but the board has never been powered on. I now need the design taken all the way from desk-review to a fully working, calibrated prototype.

Here is what I’m expecting: you will start by combing through the design files to spot any signal-integrity or component issues that could compromise measurement accuracy. From there, please revise the board so the LCD module and both sensor inputs are properly routed and shielded. Once the updates are done, arrange a quick turn build, assemble at least one board, load the firmware, and make any code tweaks needed to drive the display or improve linearity.

The most critical phase is hands-on testing and calibration. Using standard pH buffers and conductivity solutions, verify accuracy, repeatability, and temperature compensation, then store the resulting coefficients in on-board memory. I’d like a concise report that shows raw data, calibration curves, and the final performance figures.

When you apply, focus on your practical experience bringing up and calibrating electronic prototypes—especially anything involving low-noise analog front ends, sensor interfaces, or small LCDs. A quick note on your lab equipment and similar projects you’ve completed will help me decide fast.

Deliverables
• Updated schematic, PCB, and Gerber files ready for fab
• Revised BOM and LCD/sensor integration notes
• Compiled firmware plus source with your modifications
• One fully functional, calibrated prototype (or a clear build guide if shipping is not possible)
• Test & calibration report with documented procedures and results

I’m ready to get started as soon as I find the right fit.