/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

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 /boot/config.txt: 
      [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
    3. install can-utils sudo apt install can-utils
    4. evaluate if the can0 is on your SPI bus ls /sys/bus/spi/devices/spi0.0/net/(it should show 'can0')
    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 
      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

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
    1. 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
    2. 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