ardupilot/Tools/Linux_HAL_Essentials

PRU PWM

###Updating kernel

• Check your kernel version using uname -r
• If you get 3.8.13bone56+ as output then you may skip Updating kernel.
• For other kernel versions write following cmds in your BBB:

wget https://rcn-ee.net/deb/wheezy-armhf/v3.8.13-bone57/install-me.sh
chmod +x install-me.sh
./install-me.sh

• After above steps reboot and check your kernel version using uname -r,it should be 3.8.13bone57

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NOTE: For Ubuntu different scripts shall be used. E.g., for precise: - http://rcn-ee.net/deb/precise-armhf/v3.8.13-bone57/install-me.sh

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###Setting Up PRU Compiler You should first check if there is the PRU Compiler available in your Linux-Distribution.

• apt-get update
• sudo apt-get install ti-pru-cgt-installer

If it is not available in your Linux-Distribution you have to download it from the TI website.

• Download PRU C Compiler v2.0.0B2 installer
• Please check the path where you install PRU compiler.
• Setting environment variable

echo export PATH=/path/to/pru/compiler/bin:$PATH >> ~/.bashrc
echo export PRU_C_DIR="/path/to/pru/compiler/include;/path/to/pru/compiler/lib" >> ~/.bashrc
source ~/.bashrc

note: semicolons in second command were intended

###Compiling and loading the code

• just make
• copy generated executable pwmpru1 to ardupilot/Tools/Linux_HAL_Essentials/.
• To load firmware use
  • ./startup.sh load : only once after reboot it will copy overlays and firmware to /lib/firmware/ and loads them.
  • ./startup.sh reload : it only copies firmware to /lib/firmware/ and reloads pru firmware.
• Enable loading cape during BBB startup (no need to follow above step if you do this step once):
  • cp BB-PXF-01-00A0.dtbo /lib/firmware
  • add cape_enable=capemgr.enable_partno=BB-PXF-01 to /boot/uboot/uEnv.txt
  • add CAPE=BB-PXF-01 to /etc/default/capemgr