BTS7960 Motor Controller

ESP32-based DC motor controller with web interface, using BTS7960 dual H-bridge driver with current sensing and stall protection.

Hardware

Components

Component	Model/Specification
Microcontroller	ESP32 LOLIN32 Rev1
Motor Driver	BTS7960 Dual H-Bridge Module
Power Supply	12V DC
Sense Resistors	2× 1kΩ (for current sensing)

BTS7960 Module Reference

• DeepBlue Embedded Guide
• BTN7960 Datasheet

Wiring

Motor Control Pins

BTS7960 Pin	ESP32 GPIO	Function
RPWM	GPIO25	Forward PWM
LPWM	GPIO26	Reverse PWM
R_EN	GPIO27	Right Enable
L_EN	GPIO14	Left Enable
VCC	3.3V	Logic Power
GND	GND	Ground

Current Sensing Circuit

The BTS7960 has IS (Current Sense) pins that output current proportional to motor load. A resistor converts this to voltage for ESP32 ADC.

BTS7960 Module                    ESP32
┌─────────────────┐              ┌──────┐
│                 │              │      │
│  R_IS (pin 7)  ─┼──────┬───────┤GPIO34│
│                 │      │       │      │
│                 │     [R1]     │      │
│                 │     1kΩ      │      │
│                 │      │       │      │
│  GND           ─┼──────┴───────┤GND   │
│                 │              │      │
│  L_IS (pin 8)  ─┼──────┬───────┤GPIO35│
│                 │      │       │      │
│                 │     [R2]     │      │
│                 │     1kΩ      │      │
│                 │      │       │      │
│  GND           ─┼──────┴───────┤GND   │
└─────────────────┘              └──────┘

Connection	Details
R_IS → GPIO34	Through 1kΩ resistor to GND
L_IS → GPIO35	Through 1kΩ resistor to GND

Note: GPIO34 and GPIO35 are input-only pins on ESP32, ideal for ADC readings.

Current Sensing Math

Parameter	Value	Formula
Sense Ratio	8500:1	I_sense = I_motor / 8500
Sense Resistor	1kΩ	V_sense = I_sense × R
At 4A motor current	0.47V	(4 / 8500) × 1000
Max readable current	28A	(3.3V × 8500) / 1000

Configuration

Key settings in include/config.h:

Setting	Default	Description
STALL_CURRENT_THRESHOLD	4.0A	Current triggering stall detection
STALL_DETECT_TIME_MS	500ms	Duration before stall confirmed
PWM_FREQ	20kHz	PWM frequency (reduces motor noise)
CURRENT_SENSING_ENABLED	true	Enable/disable in src/motor.cpp

Network

Setting	Value
WiFi SSID	tami
Static IP	10.81.2.185
HTTP Port	80

Build & Upload

pio run              # Build
pio run -t upload    # Build and upload
pio device monitor   # Serial monitor (115200 baud)

Stall Protection

When motor current exceeds 4.0A for 500ms continuously:

1. Stall is detected
2. Motor stops immediately
3. Serial log: STALL PROTECTION: Stopping motor (current: X.XXA)

To resume operation, send a new speed/direction command via the web interface.