Autoclicker carrier

AutoClicker Carrier PCB v1.0

A 40 × 25 mm carrier board that takes the breadboard rats-nest off the bench and turns the ESP32-C3 SuperMini + MG90S servo into a clean, screw-mountable module.

What it does

• Sockets the ESP32-C3 SuperMini on two 1×8 female header strips (no soldering of the module — pull it off any time)
• Routes 5V / GND / GPIO3 through copper traces to a 3-pin JST-PH connector for the MG90S pigtail
• Holds a 470 µF electrolytic across the 5V rail to absorb servo inrush spikes
• Lights a small red status LED whenever the board is powered
• Drops into any enclosure via four M2 mounting holes

USB-C lives on the SuperMini itself — it pokes off the LEFT short edge of the carrier so you can plug a powerbank straight in.

Dimensions

Bill of materials

Total ~₱65 in components per board, plus the shared PCB cost. SuperMini and servo come from the existing build.

Schematic (textual)

  [USB-C 5V] ─┬─ ESP32-C3 5V ───┬───── J2 pin 1 (5V, red wire)
              │                 ├──[+] C1 [−]── ESP32-C3 GND
              └──── R1 ── D1[A] D1[K] ── ESP32-C3 GND
  ESP32-C3 GND ─────────────────┴───── J2 pin 3 (GND, brown wire)
  ESP32-C3 GPIO3 ────────────────────  J2 pin 2 (SIG, orange/yellow wire)

Three signal nets total. No transistor, no MOSFET, no flyback diode — the servo is a non-inductive load (from the firmware's perspective; the gear motor's brushes are inside the servo's own controller).

Manufacturing

Option A — JLCPCB (recommended starting point)

1. Open autoclicker-carrier.svg in KiCad PcbNew → File ▸ Import ▸ Graphics, scale 1.0, layer Edge.Cuts for the outline + F.SilkS for labels.
2. Place footprints from the standard libraries:
   • Connector_PinHeader_2.54mm:PinHeader_1x08_P2.54mm_Vertical × 2
   • Connector_JST:JST_PH_S3B-PH-K_1x03_P2.00mm_Horizontal
   • Capacitor_THT:CP_Radial_D8.0mm_P5.00mm
   • LED_THT:LED_D5.0mm
   • Resistor_THT:R_Axial_DIN0207_L6.3mm_D2.5mm_P2.54mm_Vertical
   • MountingHole:MountingHole_2.2mm_M2
3. Route the three traces shown above on the top copper layer (default 0.4 mm trace width is fine for ~1 A).
4. Pour a GND fill on the bottom layer and stitch with a few vias for thermal mass.
5. File ▸ Plot → Gerbers + drill files (Excellon, metric, decimal). Zip them.
6. Upload to JLCPCB. Defaults are correct for this design: 1.6 mm FR-4, HASL lead-free, 2 layers, green soldermask, white silkscreen. Order qty 5 — minimum is cheaper than qty 1.

Option B — toner transfer / hand-etched

The design is simple enough (3 nets) that a hand-routed single-sided board works. Mirror the SVG, print on glossy paper, transfer with a hot iron onto copper-clad, etch with ferric chloride. Drill with a 1.0 mm bit for the through-holes and 2.2 mm for mounting.

Assembly

1. Solder the two 1×8 female headers first — flip the board upside-down on a flat surface with the headers in place to ensure they sit perpendicular.
2. Solder J2 (JST-PH), watching polarity against the silkscreen.
3. Solder C1 with the long lead in the + pad (left side, near the trace from 5V). Cap polarity is critical — backwards = bulging cap.
4. Solder R1 (any direction) and D1 (long lead = anode = + end, marked on silk).
5. Plug the SuperMini onto the headers. USB-C should poke off the left short edge.
6. Plug the MG90S pigtail onto J2. Check the wire colors against the silkscreen: red (5V) → pin 1, orange/yellow (signal) → pin 2, brown (GND) → pin 3. MG90S pin order can differ between clones — always verify against the silkscreen, not your last build.

File map

pcb/
├── autoclicker-carrier.kicad_pro   ← KiCad project file (open this one in KiCad)
├── autoclicker-carrier.kicad_pcb   ← Board layout — opens in PcbNew
├── autoclicker-carrier.svg         ← 1:1 reference drawing (Inkscape / browser)
└── README.md                       ← this document

Opening in KiCad

1. Install KiCad 8 or later (free, cross-platform).
2. Open KiCad. File ▸ Open Project → pick autoclicker-carrier.kicad_pro.
3. From the project window, double-click the PCB file (or click the green PCB Editor button) to open the board in PcbNew. You'll see:
   • 40 × 25 mm board outline on Edge.Cuts
   • 4 mounting holes (M2, NPTH)
   • 2 socket strips for the SuperMini (J1 with the 5V/GND/SIG nets assigned, J2 as passthrough)
   • JST-PH 3-pin servo connector (J3)
   • 470 µF cap (C1), 5 mm LED (D1), 330 Ω resistor (R1)
   • Pre-routed copper: +5V / SIG / LED_A on F.Cu (top), GND on B.Cu (bottom)
   • Silkscreen labels: AUTOCLICKER, v1.0, pin labels at the JST, USB-C arrow, GPIO3 callout
4. Run Inspect ▸ Design Rules Checker — should pass with default DRC. If anything trips, the most likely cause is footprint clearances tighter than the global 0.2 mm clearance.
5. File ▸ Plot… to export Gerbers (defaults are fine — turn on F.Cu / B.Cu / F.SilkS / F.Mask / B.Mask / Edge.Cuts). Then Generate Drill Files… for the Excellon .drl. Zip everything in gerber/ and upload to JLCPCB.

Note on embedded footprints

The footprints (Custom:PinSocket_1x08_Horizontal, etc.) are embedded in the .kicad_pcb file — they don't reference any external library, so they'll resolve cleanly even on a fresh KiCad install with no extra libraries downloaded. The standard libraries (MountingHole, Connector_JST, Capacitor_THT, LED_THT, Resistor_THT) are also referenced for the parts that match KiCad's defaults; if you don't have them installed (highly unusual), KiCad will fall back to the embedded copies.

No schematic — that's intentional

This is a board-only project (no .kicad_sch). The netlist is defined directly via pad net assignments in the PCB file. To add a schematic later: File ▸ New ▸ Schematic, draw the symbols, and run Tools ▸ Update PCB from Schematic to sync.

The SVG (autoclicker-carrier.svg) is a reference drawing — useful as an Inkscape source for graphics or as a printable 1:1 template, but it's not what you fab from. Always generate Gerbers from KiCad.

Status

Designed but not yet manufactured. v1.0 is a paper design. Once a batch is fabbed and assembled, this file will be updated with errata.