Raspberry Pi 4 Model B

Overview

Raspberry Pi 4 Model B is powered with Broadcom BCM2711, quad-core Cortex-A72 (ARM v8) 64-bit SoC @ 1.5GHz. This product’s key features include a high-performance 64-bit quad-core processor, dual-display support at resolutions up to 4K via a pair of micro-HDMI ports, hardware video decode at up to 4Kp60, and the RAM size various from 2GB, 4GB, or 8GB, dual-band 2.4/5.0GHz wireless LAN, Bluetooth 5.0, Gigabit Ethernet, USB 3.0, and PoE capability (via a separate PoE HAT add-on). The dual-band wireless LAN and Bluetooth have modular compliance certification, allowing the board to be designed into end products with significantly reduced compliance testing, improving both cost and time to market.

Applications

  • Embedded Design & Development

  • Hobby & Education

  • IoT (Internet of Things)

  • Communications & Networking

Hardware

For more details on the Raspberry Pi 4 board, see Raspberry Pi hardware page.

Working with the board

Building All Scenarios OS image

To clone the source code, perform the procedure in: Setting up a repo workspace.

Linux image

  1. Source the environment with proper template settings, the flavour being linux and target machine being raspberrypi4-64. Pay attention to how relative paths are constructed. The value of TEMPLATECONF is relative to the location of the build directory ./build-linux-raspberrypi4-64, which is going to be created after this step:

$ TEMPLATECONF=../oniro/flavours/linux . \
   ./oe-core/oe-init-build-env build-oniro-linux-raspberrypi4-64
  1. You will find yourself in the newly created build directory. Call bitbake to build the image. For example, if you are using allscenarios-image-base run the following command:

$ MACHINE=raspberrypi4-64 bitbake allscenarios-image-base
  1. After the build completes, the bootloader, kernel, and rootfs image files can be found in build-oniro-linux-raspberrypi4-64/tmp/deploy/images/$MACHINE/. The key file which is needed to flash into the SD card is allscenarios-image-base-raspberrypi4-64.wic.bz2.

Flashing All Scenarios OS Linux Image

SD card

The Raspberry Pi 4 board support multiple boot options. The below section describes booting the board with an SD card option.

  1. After the image is built, you are ready to burn the generated image onto the SD card. We recommend using bmaptool <https://github.com/intel/bmap-tools> and the instructions below will use it. For example, if you are building allscenarios-image-base run the following command replacing (or defining) $DEVNODE accordingly:

$ cd tmp/deploy/images/raspberrypi4-64
$ bmaptool copy allscenarios-image-base-raspberrypi4-64.wic.bz2 $DEVNODE
  1. Put the card to the board and turn it on.

Testing the board

HDMI

Two micro HDMI ports (HDMI-0 and HDMI-1) are enabled by default. Simply plugging your HDMI-equipped monitor into the RPi4 using a standard HDMI cable will automatically lead to the Pi using the best resolution the monitor supports.

For more details, see HDMI ports and configuration.

Bluetooth & BLE

By default, BT and BLE are supported.

For any fault in the hardware device, see How to handle faulty hardware device.

Ethernet & WiFi

Drivers for both Ethernet and WiFi is available by default and hence no specific configuration is needed to enable drivers for these interfaces.

Setting a static of dynamic IP for the interface is implementation and deployment specific and any network configuration tool can be used to configure IPv4 or IPv6 address to RPi.

For any fault in the hardware device, see How to handle faulty hardware device.

Audio

To enable the audio over 3.5mm jack, add the following line in your build’s local.conf:

RPI_EXTRA_CONFIG = "dtparam=audio=on"

To enable the aplay support for audio playback, append the following lines:

IMAGE_INSTALL_append = " gstreamer1.0  gstreamer1.0-meta-base
gstreamer1.0-plugins-base gstreamer1.0-plugins-good"
IMAGE_INSTALL_append = " alsa-lib alsa-utils alsa-tools"

To test the audio out on the 3.5mm audio jack, we need to download the wav file and play with aplay.

# wget https://file-examples-com.github.io/uploads/2017/11/file_example_WAV_1MG.wav
# aplay file_example_WAV_1MG.wav

Connect the headset on 3.5mm audio jack and you should be able to hear the audio.

I2C

I2C is disabled by default. To enable I2C, edit the local.conf build’s configuration adding:

ENABLE_I2C = "1"

The device tree does not create the I2C devices. For a quick test, install the module.

root@raspberrypi4-64:~# modprobe i2c_dev
[  611.019250] i2c /dev entries driver

root@raspberrypi4-64:~# ls -ls /dev/i2c-1
    0 crw-------    1 root     root       89,   1 Mar 29 10:41 /dev/i2c-1

Note

Need to be updated with more options.

GPIO

GPIO testing can be done using the sysfs Interface.

The following example shows how to test the GPIO-24 (which corresponds to physical pin number 18 on the GPIO connector of the Raspberry Pi):

By default, sysfs driver is loaded, you will see the GPIO hardware exposed in the file system under /sys/class/gpio. It might look something like this:

root@raspberrypi4-64:/sys/class/gpio# ls /sys/class/gpio/
export       gpiochip0    gpiochip504  unexport

We’ll look at how to use this interface next. Note that the device names starting with gpiochip are the GPIO controllers and we won’t directly use them.

To use a GPIO pin from the sysfs interface, perform the following steps:

  1. Export the pin.

# echo 24 >/sys/class/gpio/export
  1. Set the pin direction (input or output).

# echo out >/sys/class/gpio/gpio24/direction
  1. If an output pin, set the level to low or high.

To validate the GPIO24 pin value, connect the LED light with the positive line on pin #18 (GPIO24) and the negative line on pin #20 (Ground).

# echo 0 >/sys/class/gpio/gpio24/value  # to set it low - LED Turn OFF
# echo 1 >/sys/class/gpio/gpio24/value  # to set it high - LED Turn ON
  1. If an input pin, read the pin’s level (low or high).

# cat /sys/class/gpio/gpio24/value  # 0 is low & 1 is high.
  1. When done, unexport the pin.

# echo 24 >/sys/class/gpio/unexport