drone-medium

This is a documention repo on how can you make your Raspberry Pi a medium for debugging and communicating to dronecan nodes through CAN and SWD

CAN setup

via MCP2515

Raspberry 4

• Signal Connection

  

RP4 HEADR	RP4 GPIO	SIGNAL	MCP2515 TJA1050 MODULE
#01	Power	3,3V	VCC
#02	Power	5V	Extra wire to TJA1050 VCC
#06	Power	GND	GND
#09	Power	GND	GND to CAN BUS (there is no GND terminal on CAN MODULE)
#19	GPIO 10	MOSI	SI
#21	GPIO 9	MISO	SO
#23	GPIO 11	SCLK	SCK/CLK
#24	GPIO 8	SPI0.CE0	CS
#32	GPIO 12	INT	INT

• Inteface Configuration

  1. update your packages

  sudo apt update && sudo apt upgrade
  

  2. append the following lines to your configration file located in

  sudo nano /boot/config.txt
  

  do next changes:

    ```
    [all]
    dtparam=spi=on
    #dtoverlay=mcp2515-can0,oscillator=<oscillator-frequency-in-hertz>,interrupt=<gpio-for-interrupt-pin>
    # in our case
    dtoverlay=mcp2515-can0,oscillator=16000000,interrupt=12
    ```
  

  sudo reboot
  

  3. install can-utils

  sudo apt install can-utils
  

  4. evaluate if the can0 is on your SPI bus (it should show 'can0')

  ls /sys/bus/spi/devices/spi0.0/net/
  

  5. set up yor can interface

  sudo ip link set can0 up type can bitrate 1000000
  

   > the bitrate for our case is 1000000, you may change it to your preffered bitrate
  

  6. check if can0 is interface

  sudo ifconfig
  

  it should be something like this

        mbed@ahuratus:~ $ ifconfig
        can0: flags=193<UP,RUNNING,NOARP>  mtu 16
                unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 10  (UNSPEC)
                RX packets 396  bytes 3168 (3.0 KiB)
                RX errors 0  dropped 0  overruns 0  frame 0
                TX packets 0  bytes 0 (0.0 B)
                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
  
  

  7. Finally now you can send or receive something overthe bus using candump and cansend

     mbed@ahuratus:~ $ candump can0
     can0  1801555C   [8]  1A 00 00 00 00 02 00 D4
     can0  1801555C   [8]  1B 00 00 00 00 02 00 D5
     can0  1801555C   [8]  1B 00 00 00 00 02 00 D6
     

DroneCAN

To test Dronecan just use one of examples in the next repo https://github.com/dronecan/pydronecan

SWD setup

via BCM2835 and Open On-Chip Debugger

Raspberry 4

• Signal Connection

RP4 HEADR	RP4 GPIO	SIGNAL
#17	Power	3,3V
#20	Power	GND
#18	GPIO 24	SWCLK
#22	GPIO 25	SWIO

• Build and Install openocd

  1. Install building utils sudo apt-get install git autoconf libtool make pkg-config libusb-1.0-0 libusb-1.0-0-dev
  2. Clone openocd repository git clone http://openocd.zylin.com/openocd
  3. cd openocd;chmod +x ./bootstrap; chmod +x ./configure;
  4. ./bootstrap
  5. configure bcm2835 ./configure --enable-sysfsgpio --enable-bcm2835gpio
  6. make
  7. Install openocd sudo make install

• configre swd via openocd on raspberry pi 4

  1. create an openocd interface in directory <openocd_directory>/scripts/interface/raspberrypi4-native.cfg using the following command

  sudo echo "#
  # Config for using Raspberry Pi's expansion header
  #
  # This is best used with a fast enough buffer but also
  # is suitable for direct connection if the target voltage
  # matches RPi's 3.3V and the cable is short enough.
  
  adapter driver bcm2835gpio
  bcm2835gpio peripheral_base 0x3F000000
  
  # Transition delay calculation: SPEED_COEFF/khz - SPEED_OFFSET
  
  
  # These depend on system clock, calibrated for stock 700MHz
  # bcm2835gpio speed SPEED_COEFF SPEED_OFFSET
  bcm2835gpio speed_coeffs 146203 36
  
  
  # Each of the SWD lines need a gpio number set: swclk swdio
  # swd gpio pins      swclk swio
  adapter gpio swclk 24
  adapter gpio swdio 25
  
  adapter speed 100
  transport select swd
  " > /usr/local/share/openocd/scripts/interface/raspberrypi4-native.cfg
  

  2. Now create your gdb configuration

     echo "
     source [find interface/raspberrypi4-native.cfg]
     # for STM32F1xx mcus
     set CHIPNAME stm32f1
     source [find target/stm32f1x.cfg]
     # did not yet manage to make a working setup using srst
     #reset_config srst_only
     reset_config  srst_nogate
     init
     targets
     reset halt
     ">openocd.cfg
     

  3. start debugging sudo openocd

       mbed@ahuratus:~ $ openocd 
       Open On-Chip Debugger 0.12.0-rc2+dev-00019-g9d925776b (2022-11-23-13:01)
       Licensed under GNU GPL v2
       For bug reports, read
       	http://openocd.org/doc/doxygen/bugs.html
       Info : BCM2835 GPIO JTAG/SWD bitbang driver
       Info : clock speed 1001 kHz
       Info : SWD DPIDR 0x1ba01477
       Info : [stm32f1.cpu] Cortex-M3 r1p1 processor detected
       Info : [stm32f1.cpu] target has 6 breakpoints, 4 watchpoints
       Info : starting gdb server for stm32f1.cpu on 3333
       Info : Listening on port 3333 for gdb connections
       [stm32f1.cpu] halted due to debug-request, current mode: Thread 
       xPSR: 0x01000000 pc: 0x080015b8 msp: 0x20005000
       Info : Listening on port 6666 for tcl connections
       Info : Listening on port 4444 for telnet connections