4.6 Connect Spindles and Laser

PWM, laser PWM, 0-10 V and Modbus RS485 control options

Control signals are not motor power. V4.7B does not power a spindle or laser from the GPIO headers. Use the equipment's proper power supply, interlocks, enclosure, emergency stop and protective earth. Have mains/VFD wiring performed by a qualified person.

〰️

GPIO 4 PWM
5 V speed signal

🔴

GPIO 12 Laser
TTL/PWM control

0–10 V

GPIO 13 Analog
VFD speed input

A⇄B

RS485 Modbus
digital VFD control

Interface	Test-YAML pin/tool	Typical use
5 V PWM	GPIO 4 / T0 / S0-10000	PWM spindle or compatible control input
Laser PWM	GPIO 12 / T1 / S0-255	Laser TTL/PWM input
0-10 V analog	GPIO 13 / T2 / S1000-24000	VFD analog-speed input
RS485 Modbus	GPIO 15/16/14 / T3	Digital VFD control

Connection sequence

Choose one control method supported by the spindle/laser/VFD manual.
Complete the corresponding bench test with the equipment physically disconnected.
Copy the relevant section into the machine YAML and set the real S-value range, safe boot/alarm state, spin-up time and direction behavior.
Power off, connect signal and signal ground exactly as documented, keeping signal cables away from VFD output and motor wires.
Commission at minimum power/speed with motion disabled, then verify stop, reset, alarm and communication-loss behavior.

GPIO sharing: GPIO 4 and 12 also control the two MOSFET outputs. GPIO 14/15 serve RS485 direction/TX and also feed the 0-10 V Forward/Reverse contact circuit. Design the YAML so shared signals have only one intended role.

Acceptance check: command direction and speed match the equipment, M5 stops it, startup/alarm states are safe, and no output activates unexpectedly during reset.

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