====== freenove ======
* https://github.com/Freenove/Freenove_4WD_Smart_Car_Kit_for_Raspberry_Pi
* https://www.raspberrypi.com/software/operating-systems/
before boot mount bootfs
echo "pi:$6$c70VpvPsVNCG0YR5$l5vWWLsLko9Kj65gcQ8qvMkuOoRkEagI90qi3F/Y7rm8eNYZHW8CY6BOIKwMH7a3YYzZYL90zf304cAHLFaZE0" > userconf.txt
touch ssh.txt
blacklist audio on rasp 3
echo "blacklist snd_bcm2835" >> /etc/modprobe.d/snd-blacklist.conf
===== python library =====
git clone https://github.com/Freenove/Freenove_4WD_Smart_Car_Kit_for_Raspberry_Pi
tests
cd ~/Freenove_4WD_Smart_Car_Kit_for_Raspberry_Pi/Code/Server
sudo python test.py Motor
sudo python test.py Led