Python binding for RaspberryPi vcgencmd command-line tool

Summary

'vcgencmd' is a command line utility that can get various pieces of information from the VideoCore GPU on the Raspberry Pi. This Python package is a binding to that tool.

Install

vcgencmd is compatible with both Python2.7+ and Python3.x. These instructions will be for Python 3.x. You can substitute the python and pip commands accordingly for other versions. The installer requires the setuptools package.

(Note: DEPRECATION: Python 2.7 reached the end of its life on January 1st, 2020.)

Requirements

Pip (Python 3 version):

sudo apt-get install python3-pip

Setuptools (Python 3 version):

sudo pip3 install setuptools

Python package manager (PIP)

Install globally:

sudo pip3 install vcgencmd

Install locally:

pip3 install --user vcgencmd

Source installation

Install globally:

sudo pip3 install -e .

Install locally:

pip3 install -e . --user

Uninstall

sudo pip3 uninstall vcgencmd

Usage

from vcgencmd import Vcgencmd

vcgm = Vcgencmd()
output = vcgm.version()
print(output)

Commands

get_sources(src)

Returns list of all possible sources/arguments, required for some of the methods listed below.

Example: get_sources("mem") will return ["arm", "gpu"] which are the sources/arguments for get_mem(source) that returns the memory of the source passed as argument to it.

vcos_version()

Returns a string with build date and version of the firmware on the VideoCore.

vcos_log_status()

Returns the error log status of the various VideoCore software areas in JSON format.

version()

Returns the string containing build date and version of the firmware on the VideoCore.

get_camera()

Returns the enabled and detected state of the official camera in JSON format. 1 means yes, 0 means no. Whilst all firmware (except cutdown versions) will support the camera, this support needs to be enabled by using raspi-config.

get_throttled()

Returns the throttled state of the system in JSON format. This is a bit pattern - a bit being set indicates the following meanings:

Bit	Meaning
0	Under-voltage detected
1	Arm frequency capped
2	Currently throttled
3	Soft temperature limit active
16	Under-voltage has occurred
17	Arm frequency capping has occurred
18	Throttling has occurred
19	Soft temperature limit has occurred

A value of zero indicates that none of the above conditions is true.

To find if one of these bits has been set, convert the value returned to binary, then number each bit along the top. You can then see which bits are set. For example:

0x50000 = 0101 0000 0000 0000 0000

Adding the bit numbers along the top we get:

19 18 17 16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
 0  1  0  1  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0  0

From this we can see that bits 18 and 16 are set, indicating that the Pi has previously been throttled due to under-voltage, but is not currently throttled for any reason.

measure_temp()

Returns the temperature of the SoC as measured by the on-board temperature sensor.

measure_clock(clock)

This returns the current frequency of the specified clock in Hertz. List of clock options can be retrieved by get_sources("clock"). The options are:

clock	Description
arm	ARM cores
core	VC4 scaler cores
H264	H264 block
isp	Image Signal Processor
v3d	3D block
uart	UART
pwm	PWM block (analogue audio output)
emmc	SD card interface
pixel	Pixel valve
vec	Analogue video encoder
hdmi	HDMI
dpi	Display Peripheral Interface

measure_volts(block)

Returns the current voltage used by the specific block in volts. List of voltage sources can be retrieved by get_sources("volts"). The options are:

block	Description
core	VC4 core voltage
sdram_c
sdram_i
sdram_p

otp_dump()

Returns the content of the One Time Programmable (OTP) memory, which is part of the SoC. These are 32 bit values, indexed from 8 to 64, in JSON format. See the OTP bits page for more details.

get_mem(type)

Returns the amount of memory allocated to the ARM cores and the VC4, in Megabytes. List of memory type options can be retrieved by get_sources("mem"). The options are:

type	Description
arm	ARM core
gpu	VC4

Note: On a Raspberry Pi 4 with greater than 1GB of RAM, the arm option is inaccurate. This is because the GPU firmware which implements this command is only aware of the first gigabyte of RAM on the system, so the arm setting will always return 1GB minus the gpu memory value. To get an accurate report of the amount of ARM memory, use one of the standard Linux commands, such as free or cat /proc/meminfo

codec_enabled(type)

Returns whether the specified CODEC type is enabled, in boolean type. Possible options for type are AGIF, FLAC, H263, H264, MJPA, MJPB, MJPG, MPG2, MPG4, MVC0, PCM, THRA, VORB, VP6, VP8, WMV9, WVC1. This list can be retrieved by get_sources("codec"). Those highlighted currently require a paid for licence (see the FAQ for more info), except on the Pi4, where these hardware codecs are disabled in preference to software decoding, which requires no licence. Note that because the H265 HW block on the Raspberry Pi4 is not part of the Videocore GPU, its status is not accessed via this command.

get_config(type | name)

This returns a JSON object of all the configuration items of the specified type that have been set in /boot/config.txt, or a single configuration item. Possible values for type parameter are int, str, or simply use the name of the configuration item.

get_lcd_info()

Returns the resolution and colour depth of any attached display, in JSON format.

mem_oom()

Return JSON object containing statistics on any Out Of Memory events occuring in the VC4 memory space.

mem_reloc_stats()

Return JSON object containing statistics from the relocatable memory allocator on the VC4.

read_ring_osc()

Return JSON object containing the curent speed, voltage and temperature of the ring oscillator.

hdmi_timings()

Returns the current HDMI settings timings, in JSON format. See Video Config for details of the values returned.

dispmanx_list()

Returns a JSON object of all dispmanx items currently being displayed.

display_power_on(display)

Sets the display power state to on of the display whose ID is passed as the parameter.

display_power_off(display)

Sets the display power state to off of the display whose ID is passed as the parameter.

display_power_state(display)

Returns the display power state as on or off of the display whose ID is passed as the parameter.

The display ID for the preceding three methods are determined by the following table.

Display	ID
Main LCD	0
Secondary LCD	1
HDMI 0	2
Composite	3
HDMI 1	7