.. _beagleplay-mikrobus: Using mikroBUS ############## Steps: 1. Identify if mikroBUS add-on includes a ClickID with ``manifest``. If not, ``manifest`` must be supplied. 2. Identify if mikroBUS add-on is supported by the kernel. If not, kernel module must be added. 3. Identify how driver exposes the data: IIO, net, etc. 4. Connect and power 5. Verify and utilize .. _beagleplay-mikrobus-clickid: Using boards with ClickID ************************* What is mikroBUS? ================= mikroBUS is an open standard for add-on boards for sensors, connectivity, displays, storage and more with over 1,400 available from just a single source, `MikroE `_. With the flexibility of all of the most common embedded serial busses, UART, I2C and SPI, along with ADC, PWM and GPIO functions, it is a great solution for connecting all sorts of electronics. .. note:: Learn more at https://www.mikroe.com/mikrobus What is ClickID? ================ ClickID enables mikroBUS add-on boards to be identified along with the configuration required to use it with the mikroBUS Linux driver. The configuration portion is called a ``manifest``. .. note:: Learn more at https://github.com/MikroElektronika/click_id BeaglePlay's Linux kernel is patched with a mikrobus driver that automatically reads the ClickID and loads a driver, greatly simplifying usage. Does my add-on have ClickID? ============================ Look for the "ID" logo on the board. It's near PWM pin on upper right hand side in the illustration shown below. .. figure:: images/mikrobus-linux-board-illustration.png :width: 940 :align: center :alt: mikroBUS clickID - BeaglePlay connection mikroBUS clickID - BeaglePlay connection If your add-on has ClickID, simply connect it while BeaglePlay is powered off and then apply power. Example of examining boot log to see a ClickID was detected. .. code:: shell-session debian@BeaglePlay:~$ dmesg | grep mikrobus [ 2.096254] mikrobus:mikrobus_port_register: registering port mikrobus-0 [ 2.096325] mikrobus mikrobus-0: mikrobus port 0 eeprom empty probing default eeprom [ 2.663698] mikrobus_manifest:mikrobus_manifest_attach_device: parsed device 1, driver=opt3001, protocol=3, reg=44 [ 2.663711] mikrobus_manifest:mikrobus_manifest_parse: Ambient 2 Click manifest parsed with 1 devices [ 2.663783] mikrobus mikrobus-0: registering device : opt3001 To use the add-on, see :ref:`beagleplay-mikrobus-using`. .. note:: Not all Click boards with ClickID have valid ``manifest`` entries. .. _beagleplay-mikrobus-without-clickid: What if my add-on doesn't have ClickID? *************************************** It is still possible a ``manifest`` has been created for your add-on as we have created over 100 of them. You can install the existing manifest files onto your BeaglePlay. First, make sure you have the latest manifests installed in your system. .. code:: console sudo apt update .. code:: console sudo apt install bbb.io-clickid-manifests Take a look at the list of ``manifest`` files to see if the Click or other mikrobus add-on board ``manifest`` is installed. .. code:: shell-session debian@BeaglePlay:~$ ls /lib/firmware/mikrobus/ 10DOF-CLICK.mnfb COMPASS-2-CLICK.mnfb I2C-2-SPI-CLICK.mnfb PWM-CLICK.mnfb 13DOF-2-CLICK.mnfb COMPASS-CLICK.mnfb I2C-MUX-CLICK.mnfb RFID-CLICK.mnfb 3D-HALL-3-CLICK.mnfb CURRENT-CLICK.mnfb ILLUMINANCE-CLICK.mnfb RF-METER-CLICK.mnfb 3D-HALL-6-CLICK.mnfb DAC-7-CLICK.mnfb IR-GESTURE-CLICK.mnfb RMS-TO-DC-CLICK.mnfb 6DOF-IMU-2-CLICK.mnfb DAC-CLICK.mnfb IR-THERMO-2-CLICK.mnfb RTC-6-CLICK.mnfb 6DOF-IMU-4-CLICK.mnfb DIGIPOT-3-CLICK.mnfb LED-DRIVER-7-CLICK.mnfb SHT1x-CLICK.mnfb 6DOF-IMU-6-CLICK.mnfb DIGIPOT-CLICK.mnfb LIGHTRANGER-2-CLICK.mnfb SHT-CLICK.mnfb 6DOF-IMU-8-CLICK.mnfb EEPROM-2-CLICK.mnfb LIGHTRANGER-3-CLICK.mnfb SMOKE-CLICK.mnfb 9DOF-CLICK.mnfb EEPROM-3-CLICK.mnfb LIGHTRANGER-CLICK.mnfb TEMP-HUM-11-CLICK.mnfb ACCEL-3-CLICK.mnfb EEPROM-CLICK.mnfb LPS22HB-CLICK.mnfb TEMP-HUM-12-CLICK.mnfb ACCEL-5-CLICK.mnfb ENVIRONMENT-CLICK.mnfb LSM303AGR-CLICK.mnfb TEMP-HUM-3-CLICK.mnfb ACCEL-6-CLICK.mnfb ETH-CLICK.mnfb LSM6DSL-CLICK.mnfb TEMP-HUM-4-CLICK.mnfb ACCEL-8-CLICK.mnfb ETH-WIZ-CLICK.mnfb MAGNETIC-LINEAR-CLICK.mnfb TEMP-HUM-7-CLICK.mnfb ACCEL-CLICK.mnfb FLASH-2-CLICK.mnfb MAGNETIC-ROTARY-CLICK.mnfb TEMP-HUM-9-CLICK.mnfb ADC-2-CLICK.mnfb FLASH-CLICK.mnfb MICROSD-CLICK.mnfb TEMP-HUM-CLICK.mnfb ADC-3-CLICK.mnfb GENERIC-SPI-CLICK.mnfb MPU-9DOF-CLICK.mnfb TEMP-LOG-3-CLICK.mnfb ADC-5-CLICK.mnfb GEOMAGNETIC-CLICK.mnfb MPU-IMU-CLICK.mnfb TEMP-LOG-4-CLICK.mnfb ADC-8-CLICK.mnfb GNSS-4-CLICK.mnfb NO2-2-CLICK.mnfb TEMP-LOG-6-CLICK.mnfb ADC-CLICK.mnfb GNSS-7-CLICK.mnfb NO2-CLICK.mnfb THERMO-12-CLICK.mnfb AIR-QUALITY-2-CLICK.mnfb GNSS-ZOE-CLICK.mnfb OLEDB-CLICK.mnfb THERMO-15-CLICK.mnfb AIR-QUALITY-3-CLICK.mnfb GSR-CLICK.mnfb OLEDC-CLICK.mnfb THERMO-17-CLICK.mnfb AIR-QUALITY-5-CLICK.mnfb GYRO-2-CLICK.mnfb OLEDW-CLICK.mnfb THERMO-3-CLICK.mnfb ALCOHOL-2-CLICK.mnfb GYRO-CLICK.mnfb OZONE-2-CLICK.mnfb THERMO-4-CLICK.mnfb ALCOHOL-3-CLICK.mnfb HALL-CURRENT-2-CLICK.mnfb PRESSURE-11-CLICK.mnfb THERMO-7-CLICK.mnfb ALTITUDE-3-CLICK.mnfb HALL-CURRENT-3-CLICK.mnfb PRESSURE-3-CLICK.mnfb THERMO-8-CLICK.mnfb ALTITUDE-CLICK.mnfb HALL-CURRENT-4-CLICK.mnfb PRESSURE-4-CLICK.mnfb THERMO-CLICK.mnfb AMBIENT-2-CLICK.mnfb HDC1000-CLICK.mnfb PRESSURE-CLICK.mnfb THERMOSTAT-3-CLICK.mnfb AMBIENT-4-CLICK.mnfb HEART-RATE-3-CLICK.mnfb PROXIMITY-10-CLICK.mnfb UV-3-CLICK.mnfb AMBIENT-5-CLICK.mnfb HEART-RATE-4-CLICK.mnfb PROXIMITY-2-CLICK.mnfb VACUUM-CLICK.mnfb AMMETER-CLICK.mnfb HEART-RATE-5-CLICK.mnfb PROXIMITY-5-CLICK.mnfb VOLTMETER-CLICK.mnfb COLOR-2-CLICK.mnfb HEART-RATE-7-CLICK.mnfb PROXIMITY-9-CLICK.mnfb WAVEFORM-CLICK.mnfb COLOR-7-CLICK.mnfb HEART-RATE-CLICK.mnfb PROXIMITY-CLICK.mnfb WEATHER-CLICK.mnfb Then, load the appropriate ``manifest`` using the ``mikrobus`` bus driver. For example, with the Ambient 2 Click, you can write that ``manifest`` to the ``mikrobus-0`` ``new_device`` entry. .. code:: bash cat /lib/firmware/mikrobus/AMBIENT-2-CLICK.mnfb > /sys/bus/mikrobus/devices/mikrobus-0/new_device .. note:: We will be adding a link to the ``mikrobus-0`` device at ``/dev/play/mikrobus`` in the near future, but you can find it for now at ``/sys/bus/mikrobus/devices/mikrobus-0``. If you need to supply an ID (manifest), this is the directory where you will do it. Manifesto: https://git.beagleboard.org/beagleconnect/manifesto Patched Linux with out-of-tree Mikrobus driver: https://git.beagleboard.org/beagleboard/linux .. note:: It'll forget on reboot... need to have a boot service. .. todo:: To make it stick, ... To use the add-on, see :ref:`beagleplay-mikrobus-using`. .. _beagleplay-mikrobus-using: Using boards with Linux drivers ******************************* Depending on the type of mikrobus add-on board, the Linux driver could be of various different types. For sensors, the most common is :ref:`beagleplay-mikrobus-using-iio`. .. _beagleplay-mikrobus-using-iio: IIO driver ========== Per https://docs.kernel.org/driver-api/iio/intro.html, The main purpose of the Industrial I/O subsystem (IIO) is to provide support for devices that in some sense perform either analog-to-digital conversion (ADC) or digital-to-analog conversion (DAC) or both. The aim is to fill the gap between the somewhat similar hwmon and input subsystems. Hwmon is directed at low sample rate sensors used to monitor and control the system itself, like fan speed control or temperature measurement. Input is, as its name suggests, focused on human interaction input devices (keyboard, mouse, touchscreen). In some cases there is considerable overlap between these and IIO. Devices that fall into this category include: * analog to digital converters (ADCs) * accelerometers * capacitance to digital converters (CDCs) * digital to analog converters (DACs) * gyroscopes * inertial measurement units (IMUs) * color and light sensors * magnetometers * pressure sensors * proximity sensors * temperature sensors See also https://wiki.analog.com/software/linux/docs/iio/iio. To discover IIO driver enabled devices, use the ``iio_info`` command. .. code-block:: console debian@BeaglePlay:~$ iio_info Library version: 0.24 (git tag: v0.24) Compiled with backends: local xml ip usb IIO context created with local backend. Backend version: 0.24 (git tag: v0.24) Backend description string: Linux BeaglePlay 5.10.168-ti-arm64-r104 #1bullseye SMP Thu Jun 8 23:07:22 UTC 2023 aarch64 IIO context has 2 attributes: local,kernel: 5.10.168-ti-arm64-r104 uri: local: IIO context has 2 devices: iio:device0: opt3001 1 channels found: illuminance: (input) 2 channel-specific attributes found: attr 0: input value: 163.680000 attr 1: integration_time value: 0.800000 2 device-specific attributes found: attr 0: current_timestamp_clock value: realtime attr 1: integration_time_available value: 0.1 0.8 No trigger on this device iio:device1: adc102s051 2 channels found: voltage1: (input) 2 channel-specific attributes found: attr 0: raw value: 4084 attr 1: scale value: 0.805664062 voltage0: (input) 2 channel-specific attributes found: attr 0: raw value: 2440 attr 1: scale value: 0.805664062 No trigger on this device Note that the units are standardized for the IIO interface based on the device type. If raw values are provided, a scale must be applied to get to the standardized units. .. _beagleplay-mikrobus-using-storage: Storage driver ============== .. _beagleplay-mikrobus-using-net: Network driver ============== .. _beagleplay-mikrobus-how: How does ClickID work? ********************** .. _beagleplay-mikrobus-disable: Disabling the mikroBUS driver ***************************** If you'd like to use other means to control the mikroBUS connector, you might want to disable the mikroBUS driver. This is most easily done by enabling a deivce tree overlay at boot. .. todo:: Document kernel version that integrates this overlay and where to get update instructions. .. note:: To utilize the overlay with these instructions, make sure to have TBD version of kernel, modules and firmware installed. Use `uname -a` to determine the currently running kernel version. See TBD for information on how to update. Apply overlay to disable mikrobus0 instance. .. code-block:: bash echo " fdtoverlays /overlays/k3-am625-beagleplay-release-mikrobus.dtbo" | sudo tee -a /boot/firmware/extlinux/extlinux.conf sudo shutdown -r now Log back in after reboot and verify the device driver did not capture the busses. .. code-block:: console debian@BeaglePlay:~$ ls /dev/play grove mikrobus qwiic debian@BeaglePlay:~$ ls /dev/play/mikrobus/ i2c debian@BeaglePlay:~$ ls /sys/bus/mikrobus/devices/ debian@BeaglePlay:~$ ls /proc/device-tree/chosen/overlays/ k3-am625-beagleplay-release-mikrobus name debian@BeaglePlay:~$ To re-enable. .. code-block:: bash sudo sed -e '/release-mikrobus/ s/^#*/#/' -i /boot/firmware/extlinux/extlinux.conf sudo shutdown -r now Verify driver is enabled again. .. code-block:: console debian@BeaglePlay:~$ ls /sys/bus/mikrobus/devices/ mikrobus-0 debian@BeaglePlay:~$ ls /proc/device-tree/chosen/overlays/ ls: cannot access '/proc/device-tree/chosen/overlays/': No such file or directory debian@BeaglePlay:~$ .. todo:: * How do turn off the driver? * How do turn on spidev? * How do I enable GPIO? * How do a provide a manifest? .. todo:: * Needs udev * Needs live description