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Hardware Setup

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Rendalsniken edited this page Apr 26, 2026 · 4 revisions

Hardware Setup

Bill of Materials

Component Model Qty Notes
MCU Board GUITION JC4880P443C (800x480) 1 ESP32-P4 + ESP32-C6, MIPI-DSI, GT911 touch
Stepper Driver PUL/DIR or DM542T 1 Motor Config: Standard vs DM542T
Stepper Motor NEMA 23 (3 Nm) 1
Gearbox NMRV030 + spur 1 1:108 total (60:1 x 72/40)
Power Supply 24–36V DC, >=5A (36V optimal, 24V works) 1 Dedicated for stepper driver
Potentiometer 10k linear (LA42DWQ-22) 1 Speed control, IP65
E-STOP Button NC (Normally Closed) 1 Mushroom button
Direction Switch SPDT toggle 1 CW/CCW
Foot Pedal Analog pot + momentary switch 1 Optional
DC-DC Converter 36V or 24V -> 5V 2A 1 If not using USB-C for ESP32

DIP stepper driver configuration

Set microstepping to match the Settings screen on the device:

Setting Value
Microsteps Must match UI Settings > Microstepping
Current Match your NEMA 23 rating (typically 2.5-3.0A)

Default firmware uses 1/16 (3200 pulses/rev with DM542T). Motor Config also offers 1/8 and 1/32.

Wiring Connections

ESP32-P4 to driver (signal wires)

Most PUL/DIR boards use optically isolated inputs. Wire in Common Ground configuration:

  1. Connect PUL-, DIR-, and ENA- together -> ESP32-P4 GND
  2. PUL+ (Step) -> GPIO 50
  3. DIR+ (Direction) -> GPIO 51
  4. ENA+ (Enable) -> GPIO 52

Potentiometer

Pot Pin Connect To
Pin 1 (CCW) GND
Pin 2 (Wiper) GPIO 49
Pin 3 (CW) 3.3V

Measured ADC range: 0-3315 (with 11dB attenuation on ESP32-P4).

E-STOP (GPIO 34)

Wire so released (safe) = HIGH and pressed / fault = LOW on GPIO 34 (matches safety.cpp: INPUT_PULLUP, FALLING ISR). See repository docs/HARDWARE_SETUP.md for a full discussion and EMI options.

Direction Switch (CW/CCW)

Switch Pin Connect To
Pin 1 GPIO 29
Pin 2 GND

Uses internal INPUT_PULLUP. Enable via Settings > Motor Config > Direction Switch.

Foot Pedal (optional)

Pedal Pin Connect To
Pot wiper ADS1115 AIN0 on touch I2C (SDA 7 / SCL 8) when ENABLE_ADS1115_PEDAL is enabled — not GPIO 35
Start switch GPIO 33 (INPUT_PULLUP, LOW = pressed)

Stepper motor to driver

Motor Wire Driver terminal
A+ A+
A- A-
B+ B+
B- B-

WARNING: Never connect or disconnect motor coils while the driver is powered. This will destroy the driver.

Reserved Pins

GPIO 28, GPIO 14-19, and GPIO 54 may be PCB-routed toward the ESP32-C6 co-processor. Do not repurpose without the vendor schematic. GPIO 32 is intentionally used by this firmware for DM542T ALM; do not reuse it for other signals.

Power Sequencing

  1. Power ESP32-P4 first (USB-C or DC-DC)
  2. Then power the motor supply (24V or 36V on driver VM)
  3. Firmware holds ENA HIGH (motor disabled) on boot — safe by default

Validated Hardware

Component Status
GUITION JC4880P443C Tested
PUL/DIR driver (1/4 and 1/8 microstepping) Tested
NEMA 23 (3 Nm) Tested
NMRV030 + spur (1:108 total) Tested
24–36V DC PSU (36V optimal) Tested
10k Pot (LA42DWQ-22) Tested
NC E-STOP Button Tested
Direction switch (GPIO 29) Tested
Foot pedal Tested

Known limitations (basic PUL/DIR drivers)

  • Motor resonance at 100-300 motor RPM causes stalling at coarse microstepping (1/4)
  • Use 1/8 or finer for stable operation
  • DM542T is supported; set Motor Config -> Driver to DM542T and match the DIP microstep to the UI

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