4.4 Connect Pendant
RJ12 UART2 pendant or secondary USB-host pendant
Use only a cable and pendant with the PiBot pinout. RJ12 connectors do not have a universal electrical pinout. A telephone cable that physically fits may reverse contacts or put power on the wrong pin.
Option A: RJ12 Serial Pendant
- Power off the controller.
- Connect the pendant to item 6 with the approved straight-through cable.
- The test YAML configures UART2 TX on
GPIO.0, RX on GPIO.35, 1,000,000 baud, 8N1. - Configure the pendant for serial mode at the same baud rate. For ESP3D-based PiBot pendants, set Swap RX/TX to Disable if required by the accessory documentation.
- Power on and confirm status and jog commands are exchanged.
Boot note: GPIO.0 is a boot-strap pin. If an attached device holds it low during power-up, the ESP32-S3 can enter download mode. Disconnect the pendant and restart if the board no longer boots normally.
Option B: Secondary USB Host
Item 17 can operate as UART3 USB host with the optional YAML block. First set $USBCDC/Enable=Off, enable the uart3 / usb_host section, and configure the pendant for approximately 115200 baud. See section 3.1 before permanent installation.
Acceptance check: the pendant connects after a cold boot, status updates are stable, every key controls only its intended function, and the machine E-stop remains independent of pendant software.