OpenClaw Peripheral Hardware Configuration

1. Course Overview

This course will introduce the default configuration files related to hardware before using OpenClaw, focusing on how to modify the underlying default parameters according to your actual peripheral situation and complete basic verification.

• Use low-level commands to verify if modifications take effect

2. Hardware Configuration File Description

2.1 Configuration File Location

OpenClaw's current hardware default configuration file is located at:

/home/pi/hardware_hal_demo/hardware_config.py

The default uses the factory image. If you are only following the tutorial and using the factory hardware, you usually don't need to modify it.

2.2 Current Configuration File Coverage

hardware_config.py currently mainly includes three types of default configurations:

• OpenClaw firmware serial port default parameters
• OLED default parameters

These default values are read by low-level command line tools, such as:

• rgb
• oled
• dht

Important notes:

• DHT and RGB are driven directly through the OpenClaw expansion board firmware
• OLED is driven through the motherboard's I2C pins
• CSI camera needs to check hardware connection

3. DHT Hardware Testing

Note: If you need to continuously read DHT through the Python driver library, it is recommended to read DHT data at a two-second interval, as DHT sensors are more suitable for 2s sampling

3.1 Verification Method

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dht   #Get sensor data
dht_oled  #Display sensor data on OLED

Normal terminal display will show temperature and humidity data on OLED

4. RGB Hardware Testing

4.1 Verification Method

Run in terminal:

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rgb color --color red #All turn red
rgb effect --effect breathe --color blue --speed 5 #Blue breathing light

Normal terminal display will show RGB lights displaying normally

Turn off the light strip

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rgb off

5. Servo Hardware Testing

5.1 Verification Method

Control single servo:

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servo call-tool Servo1 --action set_angle --angle 90  #Servo 1 rotates to 90 degrees
servo call-tool Servo2 --action set_angle --angle 180  #Servo 2 rotates to 90 degrees
​
#Servo1 is the servo to control
#90 is the angle to rotate to

Synchronously control multiple servos:

Note: If there are only two servos, fill in the angles for both servos, the angles for the other two servos can be arbitrary

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# Four servos simultaneously reach specified angles
servo call-tool ServoAll --action set_all --angle1 90 --angle2 45 --angle3 135 --angle4 60
# All servos return to center position
servo call-tool ServoAll --action set_all --angle1 90 --angle2 90 --angle3 90 --angle4 90

6. OpenClaw Firmware Serial Port Settings

6.1 Current Default Values

Current OpenClaw firmware serial port default parameters are:

• port="/dev/ttyAMA0"
• baudrate=115200

Other motherboards' pin serials may not be named this way. For example, Jetson's is "/dev/ttyTHS1"

6.2 Modification Example

Edit the configuration file:

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nano /home/pi/hardware_hal_demo/hardware_config.py

Change Raspberry Pi to, for example:

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"port": "/dev/ttyAMA0",
"baudrate": 115200,

6.3 Verification Method

After saving, it is recommended to first test with either servo or RGB low-level commands, for example:

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rgb color --color green

Or:

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servo call-tool Servo1 --action center  #Servo 1 returns to center 90 degrees
# All servos return to center position
servo call-tool ServoAll --action set_all --angle1 90 --angle2 90 --angle3 90 --angle4 90

If commands can return normally and peripherals can be controlled normally, the serial link is usable.

7. OLED Hardware Testing

7.1 Current Default Values

Current OLED default parameters mainly include:

• width=128
• height=32
• interface="i2c"
• i2c_bus="auto"
• i2c_bus_candidates=[1, 0, 7, 8]
• i2c_address=0x3C
• rotate=0
• invert=False
• contrast=255

7.2 Scenarios Suitable for Modification

It is recommended to modify OLED default values in the following situations:

• You are using an OLED with different resolution
• I2C address is not 0x3C
• Screen orientation needs to be flipped

7.3 Common Modification Items

Modify Resolution

For example, change from:

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"width": 128,
"height": 32,

To:

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"width": 128,
"height": 64,

Modify I2C Address

For example, change from:

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"i2c_address": 0x3C,

To:

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"i2c_address": 0x3D,

Modify Rotation Direction

For example, change from:

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"rotate": 0,

To:

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"rotate": 180,

7.4 Verification Method

After saving, run in terminal:

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oled text --text 'Hello OpenClaw'
oled clear

If OLED can display normally and clear the screen, the configuration has taken effect.

8. Camera Hardware Testing

8.1 Configuration

The premise is ensuring a CSI camera is connected. The current CSI camera chain mainly works through the following two entry points:

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/home/pi/hardware_hal_demo/camera
/home/pi/.openclaw/workspace/skills/pi-vision/scripts/csi_snap

8.2 Check Ports

Input in terminal:

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ls /dev/video*

Normally you can see video0 and video1 devices.

8.3 Photo Capture Verification Method

Input in terminal and directly test the photo capture chain:

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csi_snap snap

If the photo is taken successfully, you will usually see output files in the following directory:

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~/.openclaw/media/csi-camera/

8.4 Adjustable Parameter Description

Although camera is currently not configured in hardware_config.py, csi_snap supports some photo parameters when called, such as:

• --width
• --height
• --timeout-ms
• --rotation
• --hflip
• --vflip
• --camera

For example:

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csi_snap snap --width 1280 --height 720