Figure 1 – Breakout PCB, 3‑D view generated in the CAD tool.
Figure 2 – As‑built wiring overview of the full electronics stack.
The circuit controls fluid dosing, sample manipulation, and electrochemical sensing.
Two 12 V dosing pumps are driven through an L298N dual H‑bridge module, allowing bidirectional flow control.
Gripping and mechanical positioning are handled by two HS‑322HD standard servos, commanded directly from the Arduino's 5 V logic outputs.
An Arduino Uno serves as the central controller, generating PWM signals for the pumps and servos while streaming experimental parameters to a connected computer.
Electrochemical measurements are captured by an open‑source potentiostat module (design details on ChemRxiv), which receives experiment timing signals (PWM/trigger) from the computer and reports current/voltage data via its own USB/UART interface.
All point‑to‑point wiring is routed through a pass‑through breakout PCB fitted with screw‑terminals and header strips to keep the prototyping area tidy and to simplify hot‑swapping; however, the breakout board is strictly a convenience layer—every interconnection shown can be wired directly between the Arduino, driver boards, and sensors without impacting functionality.
| # | Component | Specification / Example Part No. | Qty |
|---|---|---|---|
| 1 | Arduino Uno R3 (or compatible) | ATmega328P‑based MCU board | 1 |
| 2 | L298N Dual H‑Bridge Motor Driver Module | 5 V logic, 46 V / 2 A per channel | 1 |
| 3 | 12 V DC Dosing Pump | Peristaltic / diaphragm, ≈0.3 A stall | 2 |
| 4 | Standard Servo Motor | HS‑322HD, 5 V supply | 2 |
| 5 | Potentiostat Board | Open‑source design (see ChemRxiv link) | 1 |
| 6 | Breakout / Routing PCB (optional) – BOM at Electrical/elec/layout/default/production/bom.csv |
Custom 2‑layer FR‑4 with screw‑terminals | 1 |
| 7 | 12 V / 2 A DC Power Supply | Barrel‑jack or Phoenix connector | 1 |
| 8 | Jumper Wires & Dupont Leads | 22 AWG stranded | — |
Quantities marked "—" depend on enclosure layout.
The breakout PCB was created with Atopile—a platform that lets you design electronics with code. use sdl_breakout.ato as the entry to the Atopile project. If you would like to directly submit the PCB files to the manufacturing, use the zip file from /elec/layout/default/production
Last updated: 2025‑04‑17