This is a port of Alt-AZ-Telescope-Position-Controller beaglebone black code to beaglebone AI64.
Some key changes.
BBAI64 does not allow for config pin instead a device tree overlay is used.
DTO set up. The BBAI64 is finicky. I sturggled getting overlays to load even pre included ones.
Start with this image https://www.beagleboard.org/distros/beaglebone-ai-64-rev-b1 before doing anything. Update APT
apt update apt upgrade apt autoclean apt autoremove
Create, Compile, and Load your Overlay. (put all pin configurations in your .dts file. once loaded it will overide changes to parent device tree mappings) copy your.dts file to /opt/source/dtb-5.10-ti/src/arm64/overlays In directory /opt/source/dtb-5.10-ti/ run:
sudo make clean sudo make sudo make install_arm64
In directory /boot/firmware/extlinux run:
sudo nano extlinux.conf uncomment and change the ftdoverlay entry to be your overlay file ftdoverlays /overlays/your.dtbo Save & exit nano
sudo reboot
This should load your overlay. (carefull one mistake in the overlay can stop the boot process and you need to reflash) check by running
sudo beagle-version |grep UBOOT xxd: Connection timed out UBOOT: Booted Device-Tree:[k3-j721e-beagleboneai64.dts] UBOOT: Loaded Overlay:[Steppercontrol.kernel]
Steppercontrol.dtbo was loaded.
**Addafruit GPIO is not ported to BBAI64 ** Use gpiod instead. Need to configure your pins in the device tree overlay. some sources https://pypi.org/project/gpiod/ https://forum.beagleboard.org/t/bb-ai64-gpio-basics/36032 https://github.com/brgl/libgpiod/blob/master/bindings/python/examples/watch_multiple_line_values.py
Ada-fruit BLinka is required for coms with the adafruit sensors IT curently is broked for AI64 make the following changes.
pip3 install Adafruit-Blinka pip3 install adafruit-circuitpython-lsm303agr-mag pip3 install adafruit-circuitpython-lsm303-accel pip3 install adafruit-circuitpython-lis2mdl pip3 install adafruit-circuitpython-mma8451
I have supporting ai64 header files in the repository, but you will still need to edit several headers.
this is how i did it (its not clean, sorry its been over 30 years since i've been in a programming class)
the adafruit attempt piggybacks on DRA74X chip id (BBAI?) to attempt to keep this open for use i created pinai64.py instead of editing the pin.py files.
Under /usr/local/lib/python3.9/dist-packages
edit digitalio.py and add the following elif statement. (I put it under the DRA74X elif entry)
elif detector.chip.TDA4VM: from adafruit_blinka.microcontroller.dra74x.pinai64 import *
edit board.py and add the following elif statement. (I put it under the BBAI elif entry)
elif board_id == ap_board.BEAGLEBONE_AI64: from adafruit_blinka.board.beagleboard.beaglebone_ai64 import * print("bbai64 select") #comment to troublshoot
under /usr/local/lib/python3.9/dist-packages/adafruit_platformdetect
edit board.py and add the following elif statement. (I put it under the BBAI elif entry)
there is a a try: statement near the bottom for the ai-64, this is trying to read 2-00500/nvmem this isn't right. try: # # Special Case for AI64 # with open("/sys/bus/nvmem/devices/2-00500/nvmem", "rb") as eeprom: # eeprom_bytes = eeprom.read(16) # except FileNotFoundError: # return None
instead use the get_device_model() method to obtain the board. beagle,j721e-beagleboneai64^@ti,j721e^@
I added following abothe the memory read try: statements.
board_value = self.detector.get_device_model() if "BeagleBone AI-64" in board_value: return boards.BEAGLEBONE_AI64 print ("board detected: ",board_value)
under /usr/local/lib/python3.9/dist-packages/microcontroller
edit pin.py and add the following elif statement. (I put it under the DRA74X elif entry)
elif chip_id == ap_chip.TDA4VM: from adafruit_blinka.microcontroller.dra74x.pinai64 import *
edit init.py and add the following elif statement. (I put it under the DRA74X elif entry)
elif chip_id == ap_chip.TDA4VM: from adafruit_blinka.microcontroller.dra74x import *
under /usr/local/lib/python3.9/dist-packages/adafruit_blinka/microcontroller/dra74x create(copy) pinai64.py
pinai64.py probably needs work, but it is corrected for the Ai64 gpio address (ex. 1, 20 for P8.3) refer to https://docs.beagleboard.io/latest/boards/beaglebone/ai-64/04-expansion.html#bbai64-expansion I couldn't find the address for the AI64 USRx LED's so they are not used. pin.py under dra74x is for something else and all adresses are wrong.
I2C2_SCL = P9_19 # was i2c4_scl I2C2_SDA = P9_20 # was i2c4_sda make sure under /usr/local/lib/python3.9/dist-packages/adafruit_blinka/microcontroller/dra74x pinai64.py order port for i2c2-5 has to match 5, I2C2 (not 3, i2c4) i2cPorts = ( (5, I2C2_SCL, I2C2_SDA), # default config (5, I2C2_SCL, I2C2_SDA), # roboticscape config (3, I2C5_SCL, I2C5_SDA), # roboticscape config )
under /usr/local/lib/python3.9/dist-packages/adafruit_blinka/board/beagleboard
edit beaglebone_ai64.py (need to copy my file in as it has disappeared from blinka
change the from statement to: from adafruit_blinka.microcontroller.dra74x import pinai64 instead of changing pin.xx_x 90 times i just added the following under the from statement: (i was tired) pin=pinai64
Remember UART and I2C pins have to be configured in the device tree overlay.
helpful commands ls -lah /dev/bone/i2c/ should see lrwxrwxrwx 1 root root 11 Jun 18 2023 2 -> ../../i2c-5 scan devices i2cdetect -r 5 the 5 is significant.
PRU
THe AI64 has more that just the 2 PRU's of the BBB. It was a painful experience to get PRU0 working.
Again the pins used need to be configured in the Device tree overlay. Do not select pins that are used for "boot select" Communication between the ARM and PRU is done by passing words back and forth via the SRAM of the PRU. This maps to 0x0b000000 on the arm side. remote proc is too slow.
The pru firmware executable is writen in C and compiled for the AI64 System on a chip (TDA4VM) this was done using TI's code composer studio. You may have to change the default memory ranges to get your program to compile. In this repository are my CCS files and settings. once compiled place your .out file in your home directory on the BBAI64 /home/debian/
echo 'stop' > /sys/class/remoteproc/remoteproc0/state cp /home/debian//Steppercontrolpru2.out /lib/firmware/Steppercontrolpru2.out echo 'Steppercontrolpru2.out' > /sys/class/remoteproc/remoteproc0/firmware echo 'start' > /sys/class/remoteproc/remoteproc0/state
Dependencies: Make sure yoru IDE is set to use Python 3, update apt and pip3 Ctypes (sudo pip3 install ctypes) install for all users Adafruit Blinka (sudo pip3 install Adafruit-Blinka) isntall for all users Pyserial (sudo pip3 install pyserial) Numpy (sudo pip3 install numpy) inputimeout 1.0.4 (sudo pip3 install inputimeout) inquirer 3.1.3 (sudo pip3 install inquirer) pynmeagps 1.0.29 (sudo pip3 install pynmeagps) Skyfield (sudo pip3 install skyfield) Flask 3.0.0 (sudo pip3 install Flask) Indigo server #sudo indigo_server (kinda flakey)
Usage. Home the scope and target something easy to find. set in auto mode and fine tune the position with the key pad or web page. once locked on a target it should switch to other targets fairly accurately.