Connections
The Prog Tool supplies 3.3 V to the target electronics for programming only. Never connect battery or motor power through it.
ESC header
A 1×6, 1.27 mm header mates pin for pin with the SWD connector on PhotonDrive speed controllers. The silkscreen letters match the ESC markings:
| Marking | Signal | Description |
|---|---|---|
| 3 | +3.3 V | Programming supply, through a ferrite bead |
| G | GND | Ground, through a ferrite bead |
| A | AUX | The ESC’s input signal line — see below |
| R | NRST | Target reset |
| D | SWDIO | SWD data |
| C | SWCLK | SWD clock |
The ESC seats over the marked area on the board, so the header lines up without a cable.
What AUX does
AUX is the signal line: the wire that carries DShot in flight carries the serial firmware update during programming. It connects to the board’s one-wire node through a 1 kΩ series resistor and the onboard transistor-and-diode circuit.
The circuit combines the serial bridge’s RX and TX paths into the single bidirectional signal used by the ESC, replacing the external adapter shown in the ESC-R Flashing Guide. Use the FT231X serial port for this connection, not a Black Magic debug port.
ST-Link-style socket
A 2×5, 2.54 mm header uses the common clone-style ST-Link V2 mapping; it is not the Arm Cortex 10-pin debug connector. Verify the pinout and orientation before making an adapter for a target that does not use the 1.27 mm connector:
| Pin | Signal | Pin | Signal | |
|---|---|---|---|---|
| 1 | NRST | 2 | SWIM | |
| 3 | GND | 4 | +3.3 V | |
| 5 | +5 V | 6 | +5 V | |
| 7 | +3.3 V | 8 | GND | |
| 9 | SWDIO | 10 | SWCLK |
Pin 2 is wired to the programmer’s SWIM signal through a 75 Ω series resistor. The hardware path is present, but operation with STM8 targets has not been verified, and SWIM is not brought out to the 1.27 mm ESC header.
Serial and signal breakouts
| RX / TX | The USB-UART bridge, brought out separately |
| DSHOT | The one-wire signal node, with ground alongside |
| +3.3 V | The regulated target supply |
These are the lines that would otherwise need a hand-built USB-to-serial adapter.
Mounting and dimensions
| Length | 76.3 mm |
| Width | 55.9 mm |
| Mounting | 4× M3 (3.2 mm plated) |
Need help with your setup? Contact us.