Monitoring Raspberry Pi Power Efficiency with CLI Commands

Learn how to check your Raspberry Pi’s power status, voltage, current consumption, temperature, and more using the command line interface. …

Learn how to check your Raspberry Pi’s power status, voltage, current consumption, temperature, and more using the command line interface.

Checking your Raspberry Pi’s power status is an essential task for ensuring optimal performance and preventing hardware damage. This article will guide you through checking your Raspberry Pi’s power status and usage using command line interface (CLI) commands.

There are two main methods to check the power consumption of a Raspberry Pi:

1. Using the vcgencmd command, which is built into the Raspbian operating system
2. Using the i2cget command with an external power monitor IC like INA219 or INA32221

Method 1: Checking Power Status using vcgencmd Command

The vcgencmd command is a built-in tool in Raspbian that provides various information about the system, including power status. To use it, open up a terminal window on your Raspberry Pi and type the following command:

vcgencmd get_throttled

This command will return a series of flags showing any current throttling issues with your Raspberry Pi. The most common throttle reasons are:

• 0x500000 - Under-voltage detected (pi is not getting enough power)
• 0x10000 - Arm frequency capped (pi is too hot and needs to cool down)
• 0x2000000 - Throttled due to the GPU memory being too high
• 0x400000 - Throttled due to the GPU not being able to reach the set frequency
• 0x8000000 - System clock frequency capped

If any of these flags are present, you may need to address them by adjusting power supply or cooling solutions.

Method 2: Checking Power Status using I2C Interface

If you have an external power monitor IC like INA219 or INA32221 connected to your Raspberry Pi, you can use the i2cget command to check power status. First, make sure you have the necessary libraries installed:

sudo apt-get install i2c-tools libi2c-dev

Next, determine the I2C bus and address of your power monitor IC. For INA219, it’s usually on bus 1 at address 0x40. You can use the following command to check:

sudo i2cdetect -y 1

This will output a grid showing all connected I2C devices. Look for your power monitor IC’s address. Once you have the bus and address, you can use i2cget to read the voltage, current, and power consumption values:

# Read voltage (in mV)
sudo i2cget -y 1 0x40 0x02

# Read current (in mA)
sudo i2cget -y 1 0x40 0x01

# Calculate power consumption (voltage * current / 1000)

Checking Temperature

To check the temperature of your Raspberry Pi, you can use the vcgencmd command:

vcgencmd measure_temp

This will return the temperature in Celsius with a format like temp=39.2'C. If the temperature is too high (typically above 60-70°C), you may need to add more heat sinks or improve airflow around your Pi.

Conclusion

Checking your Raspberry Pi’s power status and usage can help ensure optimal performance and prevent hardware damage. The vcgencmd command provides a quick and easy way to check for throttling issues, while using an external power monitor IC like INA219 or INA32221 allows for more detailed monitoring of voltage, current, and power consumption. Additionally, checking temperature is important to prevent overheating and damage to your Pi’s components.