Base Scaffold Control Panel
The control panel is the electrical front door of the Base Scaffold System: it carries the scaffold's power and signal interface and provides the connect/disconnect that mates the scaffold to a workcell each time it docks.
It is a two-board pair that mate at a blade dock. One half stays with the workcell, the other rides on the base scaffold with the project.
The Pair
| Half | Role |
|---|---|
| Workcell side (system) | Power-distribution hub and workcell controller. Bench supplies land here, every rail is metered, and power + debug are delivered across the dock. |
| Scaffold side (user) | Power and I/O dock board. Lands the supply rails, USB and user I/O on the scaffold's machine-contact field, where the project is built. |
Workcell side
Drag to orbit · wheel to zoom · right-drag to pan · the cube snaps the view.
Scaffold side
Drag to orbit · wheel to zoom · right-drag to pan · the cube snaps the view.
Mated — how the pair comes together
The two halves mate coplanar at the blade dock, with the project's molecules, jumpers and wires dropping into place:
Block Diagrams
Input power
Four independent bench-supply input to the workcell control panel. Every rail is individually metered at 20-bit precision with INA228.
| Rail | Rating | Description |
|---|---|---|
| PS1 | 0–60 V / 12 A | User variable power supply with full control |
| PS2 | 5 V / 10 A | User enabled static supply. Isolated return may float up to ±2.5 V from common |
| PS3 | — | User supply |
| PS4 | 5 V | Internal 5 V rail |
All user power supplies may be isolated by removing ground jumpers as indicated on the scaffold control panel.
Ground scheme. Large machine-pin jumpers bond a single return-to-ground per rail (default: bridged), so each rail's grounding is an explicit, per-project choice rather than a fixed assumption.
I/O available to the project
The user is given full control of the nested RP2350A, with 26 available I/O (RP2350A Mini) and USB 2.0 capable of dual data roles and power delivery. Further, the workcell side of the control panel offers two USB-SS ports capable of 3.0 protocol and power delivery.
Wireless. AX210-class module provides Wi-Fi 6E across all three bands (2.4 / 5 / 6 GHz) with 160 MHz channel width and 2×2 MIMO for link rates to ~2.4 Gbps, plus Bluetooth 5.3. Wi-Fi runs on PCIe and Bluetooth on USB.
Sensing. The panel carries on-board environmental sensing (temperature, relative humidity, barometric pressure and air quality) and 6-axis motion sensing (3-axis accelerometer + 3-axis gyroscope), both available to the project through the Control Panel Dashboard. A digital microphone is also fitted for acoustic capture.
User MCU I/O
26 user I/O reach the machine-contact field. Every line supports digital input/output, PWM and the MCU's programmable I/O; four are additionally analog-capable.
| Machine contacts | User I/O | Capabilities |
|---|---|---|
| MC31–MC34 | IO29, IO28, IO27, IO26 | Digital I/O, PWM, programmable I/O, ADC (4 analog channels), I²C / SPI / UART alternate functions |
| MC35–MC38 | IO25, IO24, IO23, IO22 | Digital I/O, PWM, programmable I/O, I²C / SPI / UART alternate functions |
| MC39–MC46 | IO19 … IO12 | Digital I/O, PWM, programmable I/O, I²C / SPI / UART alternate functions |
| MC47–MC56 | IO9 … IO0 | Digital I/O, PWM, programmable I/O, I²C / SPI / UART alternate functions |
USB
| Port | Side | Protocol | Data role | Power | Availability |
|---|---|---|---|---|---|
| USB-C | Scaffold (user) | USB 2.0 | Dual-role — host or device | Power delivery, 3.0 A; VBUS sourced from PS2 | PD unavailable while PS2 is floating (isolated by removing its ground jumper) |
| USB-C | Workcell | USB 3.0 SuperSpeed | Host | Power delivery, 3.0 A; VBUS sourced from PS2 | PD unavailable while PS2 is floating |
| USB-A | Workcell | USB 3.0 SuperSpeed | Host | Power delivery; VBUS sourced from PS2 | PD unavailable while PS2 is floating. Its USB 2.0 lanes are muxed with Bluetooth and are mutually exclusive — USB-A is unavailable while Bluetooth is in use |
USB behavior. In host role the board sources VBUS from the switched 5 V (PS2) rail through a protected path; in device role (for example, plugged into a PC) VBUS sourcing is off and back-feed into the supply is blocked. If VBUS is broken out through machine pins and CC termination is not satisfied, the CC jumper must be placed.
Debug and control across the dock
The dock carries the facilities needed to program and control the project's MCU without opening anything up: SWD and UART debug, plus boot and reset control of the user MCU, and low-voltage service rails. A companion dashboard application provides live control and telemetry — meter all four rails, set PS1 like a bench supply, switch rails, drive the scaffold I/O, and program the user MCU.
Machine contacts
Project connections land on the scaffold's machine-contact field. Two contact classes are used; both are solderless press-fit receptacles that accept a machine pin tail, a machine needle, or a bare solid-core wire.
| Property | Medium contact | Large contact |
|---|---|---|
| Current rating | ~6.4 A (80 % derated) | ~20.8 A (80 % derated) |
| Mating wire | 24 AWG solid core (precision-bent, enamel-coated) | 14 AWG solid core (precision-bent, enamel-coated) |
| Also mates with | Medium machine pin tail (Ø0.51 mm), medium needle | Large machine pin tail (Ø1.85 mm), large needle |
| Grid pitch | 2 mm within a row; rows ≥ 4 mm apart | 8 mm technical; 32 mm as implemented on the base scaffold |
Both ratings are contact-limited — the mating pin can carry more, so the contact sets the figure — and are quoted at 80 % derating for margin.
Environmental
The base scaffold and its control panel operate in a controlled 20 – 25 °C environment.
On-board sensing spans a considerably wider envelope:
| Measurement | Range |
|---|---|
| Temperature | −40 to +85 °C |
| Relative humidity | 0 to 100 % RH |
| Barometric pressure | 300 to 1100 hPa |
| Air quality | Gas-resistance based indoor air-quality sensing |
| Acceleration | ±2 / ±4 / ±8 / ±16 g selectable |
| Angular rate | ±125 to ±2000 °/s selectable |
Relationship to the Rest of the System
- The electrical boundary sits at the dock: everything upstream — bench inputs, metering and the workcell controller — is the workcell half. Everything the project touches — rails at the machine contacts, user I/O, USB and ground bonding — is the scaffold half.
- Wiring from the panels to the control panel is bent automatically; gauges and termination are documented in the Base Scaffold System — Wiring section (James/Luke).
- The project's connections terminate on the machine-contact field exactly like every other contact on the scaffold.