ESP32 + BTS7960 Rotor Controller (Yaesu G-450CDC) – GS-232(A) over Wi-Fi + Setup Portal

This sketch controls a Yaesu G-450CDC (DC motor) via ESP32 and a BTS7960/IBT-2 H-bridge.
It offers a GS-232(A) compatible Telnet interface (Port 23) and convenient service commands (calibration, brakes, filter, park).
New: Integrated Wi-Fi setup portal (AP + Captive portal) on first boot or if Wi-Fi fails.
New (2025): Multiple board support via build flags:

• Classic ESP32 (DevKit / WROOM)
• ESP32-C3 DevKitM-1
• ESP32-C3 SuperMini

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Wi-Fi Setup Portal

• Starts automatically if no Wi-Fi credentials are stored or if connection fails within 20s.
• The ESP32 opens an access point:
  • SSID: Rotor-Setup-XXXX (XXXX = last 2 MAC bytes)
  • Password: rotor1234
  • Portal: http://192.168.4.1 (captive portal via DNS redirect)
• Enter SSID and password → stored in NVS → reboot → connect as STA.

The portal provides Wi-Fi scan, save, and reset functions.

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Features

• GS-232(A) over TCP (Telnet, Port 23) – compatible with HRD, PstRotator, rotctl, etc.
• Azimuth control 0–360° or 0–450° (shortest path via 0°).
• Soft start/stop, dead time when changing direction.
• Brake modes:
  • B0 coast (free run)
  • B1 active brake (short circuit)
  • B2 PWM brake (gentle counter torque; recommended)
• Park function (P, Pxxx)
• Calibration (M adcMin adcMax) and angle range (L 0 360 / L 0 450)
• Configurable ADC filter (F n samples) for stable position readings.
• Persistent config: All settings stored in NVS (Preferences).

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Hardware

• ESP32 / ESP32-C3 (Arduino core)
• BTS7960 / IBT-2 H-bridge motor driver (6–27 V, MOSFET, 3.3 V logic compatible)
• Yaesu G-450CDC rotor (4-wire: 2x motor, 2x potentiometer)
• 20–24 V DC power supply (fused) for motor

Pin Mapping by Board

Signal	ESP32 Classic	ESP32-C3 DevKitM-1	ESP32-C3 SuperMini
RPWM (CW)	GPIO 25	GPIO 6	GPIO 4
LPWM (CCW)	GPIO 26	GPIO 7	GPIO 5
R_EN	GPIO 27	GPIO 4	GPIO 2
L_EN	GPIO 14	GPIO 5	GPIO 3
ADC (pot)	GPIO 34	GPIO 1	GPIO 0
Force AP	GPIO 0 (BOOT)	GPIO 9 (BOOT)	GPIO 9 (BOOT)

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Software – Build & Upload

PlatformIO

Board selection is done in platformio.ini via build_flags:

Build & upload with:

pio run -t upload -e esp32c3supermini

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Quick Start

1. Connect to AP Rotor-Setup-XXXX (password: rotor1234).
2. Open http://192.168.4.1 → enter your Wi-Fi credentials → save.
3. ESP32 reboots, connects as STA, starts GS-232 server on port 23.
4. Test via Telnet: telnet <esp32-ip> 23.
5. Send commands: C, A090, S, etc.

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GS-232(A) + Service Commands

Standard GS-232

Command	Description	Example
C	Report current azimuth	→ AZ123 EL000
Axxx	Rotate to azimuth xxx (000–360/450)	A090
W<az> <el>	Rotate to az only (EL ignored)	W180 000
S	Stop motion	S

Extensions

Command	Description	Example
P	Rotate to stored park position	P
Pxxx	Set new park pos & rotate immediately	P180
M <min> <max>	Calibrate ADC raw range	M 123 4012
L <min> <max>	Set logical azimuth range (360/450)	L 0 360
B0/B1/B2	Brake mode (coast, active, PWM)	B2
BP <val>	PWM brake power (0..1023)	BP 600
BT <ms>	Brake time in ms	BT 400
B?	Report brake config	→ B2 BP=600 BT=400
F <n>	ADC filter window (1..64 samples)	F 8
F?	Report current filter	→ F=8
R	Report full config	R

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Safety Notes

• Rotor has mechanical end stops – software limits are logical only.
• Use twisted pair wiring for motor lines, add ferrite cores if possible.
• Adjust PWM brake gently to avoid mechanical stress.
• Separate supply for ESP32 (5 V) and motor recommended, GND tied together.