Example Code for Raspberry Pi-Check UPS Battery Percentage

Hardware Preparation

• DFR0619 Raspberry Pi 4 Model B x1
• DFR0494 UPS HAT for Raspberry Pi x1
• FIT0120 3.7V Lithium Battery

Wiring Operation

Connect the DFRobot Raspberry Pi UPS HAT to the Raspberry Pi via the 40-pin GPIO socket. Ensure the UPS HAT is properly aligned with the Raspberry Pi's GPIO header.

Other Preparation Work

1. Enable I2C Interface on Raspberry Pi:

   1. Input command to the terminal: sudo raspi-config
   2. Select Interfacing Options (or Advanced Options) → I2C → Yes → OK
      
      
      
      
   3. Reboot Raspberry Pi using the command: reboot

2. Verify I2C Interface:

   1. Check if I2C is enabled using lsmod

      

   2. Install i2c-tools with:

      sudo apt-get install i2c-tools
      

   3. Test I2C with:

      sudo i2cdetect -y 1
      

3. Troubleshoot I2C Detection:

   If a problem like this appeared:
   

   Then change raspi-blacklist.conf configuration, raspi-blacklist.conf is under /etc/modprobe.d/ directory, input command:

   sudo nano /etc/modprobe.d/raspi-blacklist.conf
   

   Add “#” to i2c device driver, such as:#blacklist i2c-bcm2835. Now I2C interface is enabled.

Sample Code

Create ups.py file, and input the following the content:

import smbus
addr=0x10 #ups i2c address
bus=smbus.SMBus(1) #i2c-1
vcellH=bus.read_byte_data(addr,0x03)
vcellL=bus.read_byte_data(addr,0x04)
socH=bus.read_byte_data(addr,0x05)
socL=bus.read_byte_data(addr,0x06)

capacity=(((vcellH&0x0F)<<8)+vcellL)*1.25 #capacity
electricity=((socH<<8)+socL)*0.003906 #current electric quantity percentage

print("capacity=%dmV"%capacity)
print("electricity percentage=%.2f"%electricity)

Result

Run the script using python3 ups.py in the terminal. The output will display:

• capacity=XXXXmV (battery voltage in millivolts)
• electricity percentage=XX.XX (current battery percentage, rounded to two decimal places)