PWM Web Control

This page is the PWM (ESP32-S3) version-specific guide for web control. For the general interface, startup, preset poses and camera teleoperation, see the web control overview.

Hardware and flashing

• For wiring, GPIO, power and the servo model, see PWM wiring, GPIO and power.
• For firmware flashing (ESP-IDF or the prebuilt bin), see PWM quick start.
• Host ↔ ESP32 is fixed at 115200 8N1; the servos themselves have no baud rate.

Connecting from the web page

1. In the "driver" dropdown at the top, select PWM (ESP32-S3)
2. Click Add port… and select the ESP32-S3's USB serial port
3. Click Connect: the page automatically performs a handshake (NOP), sends the left/right hand selection and returns to middle
4. After that, use the sliders, preset poses and camera teleoperation to control it; the finger headings show CH 1/2 … (PWM channel numbers)

Differences from the SCS0009 version

Item	SCS0009 bus version	PWM version
Serial baud rate	1,000,000	115,200
Driver board	USB bus driver board	ESP32-S3 + PWM adapter board
Torque	can be enabled/released	none (the firmware has no torque command; the button is hidden)
E-stop	releases all torque	sends 0xFF to abort the gesture; the servos stay powered and hold position
Speed	supports a speed parameter	direct-drive frames have no speed parameter
Feedback	position/temperature/voltage/speed readback	no readback; stall or step loss cannot be detected
Left/right hand	different servo IDs	same set of channels, send 0xF1 to switch (mainly affects firmware gestures; the web poses use each hand's own mapping)

Angle calibration

The web page converts pose values into 8 angles in the range 0–180°; the default formula is:

angle = 90 + dir × scale × pose value + offset

• The first channel of each finger has dir = -1, the second has dir = +1
• By default scale = 1 and offset = 0, i.e. the servo shaft angle is mirrored directly
• When mirror_pose is true, the two pose values of each finger are swapped first (enabled for both hands in this repository)

If the direction is reversed on the real hardware or the middle position is off, edit pwm.calibration in config.json:

"pwm": {
  "calibration": {
    "right": {
      "pointer": { "scale": 1.0, "offset_deg": [0, 0] }
    }
  }
}

• Direction reversed: set the corresponding finger's scale to -1
• Middle position offset: adjust offset_deg (the two channels separately)
• Per-finger procedure: return to middle → drag one finger alone → observe the direction/middle position → change scale/offset_deg → refresh the page and retry

FAQ

• Connection failed / no response from the ESP32: confirm the baud rate is 115200, that the ESP32's COM port is selected, and that the 5 V/3 A supply and common ground are correct; opening the serial port may reset the ESP32, and the page automatically retries the NOP
• Servos do not move or jitter: first confirm the servos are 333 Hz digital servos (PTK 7452 MG-D or equivalent) and that the power supply is adequate; the SG90 requires firmware changes
• Direction reversed: set the corresponding finger's scale to -1
• Middle position incorrect: adjust the corresponding channel's offset_deg
• "Busy (gesture executing)" prompt: the firmware is executing a built-in gesture; wait for it to finish or click E-stop (0xFF)
• Scanning servos: tools/scan_servos.py only applies to SCS0009; for PWM use AmazingHand-PWM/tools/serial_test.py or the web page

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Related pages

• PWM protocol and calibration
• PWM desktop host software
• PWM quick start