# Connectors and pinout

![The connectors. The motor phases go to U, V, W; the supply to DC+ and DC−.](https://docs.source-robotics.com/Spectral-BLDC-docs/107/assets/con2.webp){ width="900" }

| Connector | Pins | Type | Cable |
|---|---|---|---|
| Motor | U, V, W | solder pads, three per phase | the motor's own leads, see [Wiring the motor](https://docs.source-robotics.com/Spectral-BLDC-docs/107/04-mounting/wiring/) |
| Power, two of them | DC+, DC− | JST XH, 2 pins | [Power cable](https://source-robotics.com/products/spectral-micro-power-cable); the second connector feeds the next driver |
| CAN, two of them | CANL, CANH | JST ZH, 2 pins | [CAN cable](https://source-robotics.com/products/spectral-micro-can-cable); the second connector feeds the next driver |
| UART | 3V3, GND, TX, RX | JST SH, 4 pins | [UART cable](https://source-robotics.com/products/uart-cable) |
| Thermistor | TERM, 3V3 | solder pads | the 100 kΩ NTC from the shop or any 100 kΩ NTC, see [Thermistor](https://docs.source-robotics.com/Spectral-BLDC-docs/107/04-mounting/thermistor/) |
| JTAG | 3V3, GND, SWCLK, SWDIO | 1.27 mm pads | [Programming adapter](https://source-robotics.com/products/jtag-programming-adapter-1-27-pitch), pressed onto the pads |
| PIN | GND, PIN, 3V3 | solder pads | your own signal: an analog input or a digital input/output, 3.3 V |
| HALL | 5V, GND, HALL1, HALL2, HALL3 | solder pads | hall sensors: not implemented in the firmware, see the note below |

![The pinout. Left the top of the board with the CAN connectors, the motor pads and the termination switch; right the bottom with the UART connector, the power connectors, the thermistor pads and the encoder chip.](https://docs.source-robotics.com/Spectral-BLDC-docs/107/assets/PINOUT1.webp){ width="900" }

!!! note "Hall sensors are not implemented"
    The HALL header and the twelve resistor pads above it are on the board for hall-sensor commutation, but the
    Spectral firmware does not implement it: the magnetic encoder is the only position source. Leave the header
    unpopulated.

!!! danger "Polarity and orientation"
    DC+ to the positive supply, DC− to the negative; a cable the wrong way round destroys the driver. The daisy-chain
    cables have an orientation too: see [Power and the CAN daisy chain](https://docs.source-robotics.com/Spectral-BLDC-docs/107/04-mounting/power-and-can/).

!!! note
    - UART is TX to RX and RX to TX between the driver and the adapter.
    - The UART port and the PIN header are 3.3 V. 5 V on either destroys the board.
    - The thermistor pin has a 54.9 kΩ pull-down; the firmware's temperature table is for a 100 kΩ NTC.
    - The CAN termination switch is next to the CAN connectors; **ON** connects the 120 Ω resistor.
    - The encoder chip sits on the bottom of the board, in the middle: that side faces the magnet.