.. _beaglev-fire-comms-cape-gateware-usage:

Comms Cape Gateware for BeagleV-Fire
#####################################

The comms cape provides an array of communication protocols including

* one RS485,
* one CAN,
* two analog 4-20 mA current loops,
* two 3A 50V interfaces allowing the control of high current loads.

Cape schematics, layout, and mechanicals
****************************************

For the schematics, layout, and mechanicals of the cape, please refer to the `Comms Cape <https://openbeagle.org/beagleboard/capes/-/tree/master/beaglebone/Comms>`_ repository.

Usage in Linux
**************

CAN
===

.. todo:: Due to the current Linux kernel being on ``6.1``, only a UIO driver is available instead of a Socket CAN driver. This section will be updated once Linux kernel ``6.6`` is shipped for the beagleV-fire, with the Socket CAN driver.

RS485
=====

The RS485 interface is connected to ``UART4`` on the BeagleV-Fire. It can be accessed using ``/dev/bone/uart/4`` in Linux.

Sink drivers
============

The sink drivers are connected to the ``P9_15`` and ``P9_23`` GPIOs. They can be controlled by writing to the GPIOs by:

.. code-block:: shell

  echo 425 > /sys/class/gpio/export
  echo 431 > /sys/class/gpio/export
  echo out > /sys/class/gpio/gpio425/direction
  echo out > /sys/class/gpio/gpio431/direction
  echo 1 > /sys/class/gpio/gpio425/value
  echo 1 > /sys/class/gpio/gpio431/value

Current loops
=============

The current loops are connected to the ADC inputs of the BeagleV-Fire at pins ``P9_35`` and ``P9_36``. They can be accessed once QSPI is enabled in the comms cape device tree overlay. The current loops can be read by:

.. code-block:: shell

    cat /sys/bus/iio/devices/iio:device0/in_voltage5_raw #Current Loop A
    cat /sys/bus/iio/devices/iio:device0/in_voltage6_raw #Current Loop B

Voltage to current conversion will have to be done in software.

Pinout
******

The full pinout for the cape interface spec can be found `here <https://docs.beagleboard.org/latest/boards/capes/cape-interface-spec.html#id18>`_ . You can also see the pinout below, refer to the last column for comms-cape specific pins.

P8 Header
=========

+--------+----------------------------+-------+-------------+
| Signal | Control                    | Irq # | Description |
+========+============================+=======+=============+
| P8_1   | n/a                        | n/a   | GND         |
+--------+----------------------------+-------+-------------+
| P8_2   | n/a                        | n/a   | GND         |
+--------+----------------------------+-------+-------------+
| P8_3   | MSS GPIO_2[0]              | 53    | User LED 0  |
+--------+----------------------------+-------+-------------+
| P8_4   | MSS GPIO_2[1]              | 53    | User LED 1  |
+--------+----------------------------+-------+-------------+
| P8_5   | MSS GPIO_2[2]              | 53    | User LED 2  |
+--------+----------------------------+-------+-------------+
| P8_6   | MSS GPIO_2[3]              | 53    | User LED 3  |
+--------+----------------------------+-------+-------------+
| P8_7   | MSS GPIO_2[4]              | 53    | User LED 4  |
+--------+----------------------------+-------+-------------+
| P8_8   | MSS GPIO_2[5]              | 53    | User LED 5  |
+--------+----------------------------+-------+-------------+
| P8_9   | MSS GPIO_2[6]              | 53    | User LED 6  |
+--------+----------------------------+-------+-------------+
| P8_10  | MSS GPIO_2[7]              | 53    | User LED 7  |
+--------+----------------------------+-------+-------------+
| P8_11  | MSS GPIO_2[8]              | 53    | User LED 8  |
+--------+----------------------------+-------+-------------+
| P8_12  | MSS GPIO_2[9]              | 53    | User LED 9  |
+--------+----------------------------+-------+-------------+
| P8_13  | core_pwm[1] @ 0x41500000   | n/a   | PWM_2:1     |
+--------+----------------------------+-------+-------------+
| P8_14  | MSS GPIO_2[11]             | 53    | User LED 11 |
+--------+----------------------------+-------+-------------+
| P8_15  | MSS GPIO_2[12]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_16  | MSS GPIO_2[13]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_17  | MSS GPIO_2[14]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_18  | MSS GPIO_2[15]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_19  | core_pwm[0] @ 0x41500000   | n/a   | PWM_2:0     |
+--------+----------------------------+-------+-------------+
| P8_20  | MSS GPIO_2[17]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_21  | MSS GPIO_2[18]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_22  | MSS GPIO_2[19]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_23  | MSS GPIO_2[20]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_24  | MSS GPIO_2[21]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_25  | MSS GPIO_2[22]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_26  | MSS GPIO_2[23]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_27  | MSS GPIO_2[24]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_28  | MSS GPIO_2[25]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_29  | MSS GPIO_2[26]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_30  | MSS GPIO_2[27]             | 53    | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_31  | core_gpio[0] @ 0x41100000  | 126   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_32  | core_gpio[1] @ 0x41100000  | 127   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_33  | core_gpio[2] @ 0x41100000  | 128   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_34  | core_gpio[3] @ 0x41100000  | 129   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_35  | core_gpio[4] @ 0x41100000  | 130   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_36  | core_gpio[5] @ 0x41100000  | 131   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_37  | core_gpio[6] @ 0x41100000  | 132   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_38  | core_gpio[7] @ 0x41100000  | 133   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_39  | core_gpio[8] @ 0x41100000  | 134   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_40  | core_gpio[9] @ 0x41100000  | 135   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_41  | core_gpio[10] @ 0x41100000 | 136   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_42  | core_gpio[11] @ 0x41100000 | 137   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_43  | core_gpio[12] @ 0x41100000 | 138   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_44  | core_gpio[13] @ 0x41100000 | 139   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_45  | core_gpio[14] @ 0x41100000 | 140   | GPIO        |
+--------+----------------------------+-------+-------------+
| P8_46  | core_gpio[15] @ 0x41100000 | 141   | GPIO        |
+--------+----------------------------+-------+-------------+

P9 Header
=========

+--------+----------------------------+-------+-------------------------+
| Signal | Control                    | Irq # | Description             |
+========+============================+=======+=========================+
| P9_1   | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+
| P9_2   | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+
| P9_3   | n/a                        | n/a   | VCC 3.3V                |
+--------+----------------------------+-------+-------------------------+
| P9_4   | n/a                        | n/a   | VCC 3.3V                |
+--------+----------------------------+-------+-------------------------+
| P9_5   | n/a                        | n/a   | VDD 5V                  |
+--------+----------------------------+-------+-------------------------+
| P9_6   | n/a                        | n/a   | VDD 5V                  |
+--------+----------------------------+-------+-------------------------+
| P9_7   | n/a                        | n/a   | SYS 5V                  |
+--------+----------------------------+-------+-------------------------+
| P9_8   | n/a                        | n/a   | SYS 5V                  |
+--------+----------------------------+-------+-------------------------+
| P9_9   | n/a                        | n/a   | NC                      |
+--------+----------------------------+-------+-------------------------+
| P9_10  | n/a                        | n/a   | SYS_RSTN                |
+--------+----------------------------+-------+-------------------------+
| P9_11  | MMUART4                    | 94    | UART4 RX <--- For RS485 |
+--------+----------------------------+-------+-------------------------+
| P9_12  | core_gpio[1] @ 0x41200000  | 143   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_13  | MMUART4                    | 94    | UART4 TX <--- For RS485 |
+--------+----------------------------+-------+-------------------------+
| P9_14  | core_pwm[0] @ 0x41400000   | n/a   | PWM_1:0                 |
+--------+----------------------------+-------+-------------------------+
| P9_15  | core_gpio[4] @ 0x41200000  | 146   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_16  | core_pwm[1] @ 0x41400000   | n/a   | PWM_1:1                 |
+--------+----------------------------+-------+-------------------------+
| P9_17  | MSS SPI0                   | 54    | SPI0 CS                 |
+--------+----------------------------+-------+-------------------------+
| P9_18  | MSS SPI0                   | 54    | SPI0 MOSI               |
+--------+----------------------------+-------+-------------------------+
| P9_19  | MSS I2C0                   | 58    | I2C0 SCL                |
+--------+----------------------------+-------+-------------------------+
| P9_20  | MSS I2C0                   | 58    | I2C0 SDA                |
+--------+----------------------------+-------+-------------------------+
| P9_21  | MSS SPI0                   | 54    | SPI0 MISO               |
+--------+----------------------------+-------+-------------------------+
| P9_22  | MSS SPI0                   | 54    | SPI0 SCLK               |
+--------+----------------------------+-------+-------------------------+
| P9_23  | core_gpio[10] @ 0x41200000 | 152   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_24  | CAN_1_RXBUS                | n/a   | CAN RX <--- For CAN     |
+--------+----------------------------+-------+-------------------------+
| P9_25  | CAN_1_TX_EBL               | 154   | CAN TX EBL              |
+--------+----------------------------+-------+-------------------------+
| P9_26  | CAN_1_TXBUS                | n/a   | CAN TX                  |
+--------+----------------------------+-------+-------------------------+
| P9_27  | core_gpio[14] @ 0x41200000 | 156   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_28  | MSS SPI1                   | 55    | SPI1 CS                 |
+--------+----------------------------+-------+-------------------------+
| P9_29  | MSS SPI1                   | 55    | SPI1 MISO               |
+--------+----------------------------+-------+-------------------------+
| P9_30  | core_gpio[17] @ 0x41200000 | 159   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_31  | MSS SPI1                   | 55    | SPI1 SCLK               |
+--------+----------------------------+-------+-------------------------+
| P9_32  | n/a                        | n/a   | VDD ADC                 |
+--------+----------------------------+-------+-------------------------+
| P9_33  | n/a                        | n/a   | ADC input 4             |
+--------+----------------------------+-------+-------------------------+
| P9_34  | n/a                        | n/a   | AGND                    |
+--------+----------------------------+-------+-------------------------+
| P9_35  | n/a                        | n/a   | ADC input 6             |
+--------+----------------------------+-------+-------------------------+
| P9_36  | n/a                        | n/a   | ADC input 5             |
+--------+----------------------------+-------+-------------------------+
| P9_37  | n/a                        | n/a   | ADC input 2             |
+--------+----------------------------+-------+-------------------------+
| P9_38  | n/a                        | n/a   | ADC input 3             |
+--------+----------------------------+-------+-------------------------+
| P9_39  | n/a                        | n/a   | ADC input 0             |
+--------+----------------------------+-------+-------------------------+
| P9_40  | n/a                        | n/a   | ADC input 1             |
+--------+----------------------------+-------+-------------------------+
| P9_41  | core_gpio[19] @ 0x41200000 | 161   | GPIO                    |
+--------+----------------------------+-------+-------------------------+
| P9_42  | core_pwm[0] @ 0x41000000   | n/a   | PWM_0:0                 |
+--------+----------------------------+-------+-------------------------+
| P9_43  | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+
| P9_44  | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+
| P9_45  | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+
| P9_46  | n/a                        | n/a   | GND                     |
+--------+----------------------------+-------+-------------------------+