March 2019
Transmit your custom audio across FM band with PiFmAdv
Instructions here
It works by using GPIO4(pin 7) which is the oscillator pin, which is used to send an RF signal.
You run:
sudo ./pi_fm_adv --freq 87.5 --audio sound.wav
Then use a radio and tune to 87.5Mhz FM and you should hear the wav file. I was chuffed when I got this to work.
Use an ADC to access analog devices with raspberry pi
Bought a MCP3008. The great thing about this ADC is that there is direct linux support for it. Enable SPI(dtparam=spi=on in /boot/config.txt or via raspi-config), make a change to /boot/config.txt (dtoverlay=mcp3008:spi0-0-present ) to load drivers at boot, then access the raw values by simply accessing a virtual file on the filesystem (cat /sys/bus/iio/devices/iio:device0/in_voltage0_raw ). Nifty.
Instructions here
Backup and restore unknown Arduino program with Raspberry Pi
Details here