It is recommended to use a 4GB or 8GB version of the Raspberry Pi 4 when runnung Ubuntu 20.10 64 bit.

sudo apt install -y build-essential git

sudo apt install -y libfftw3-dev libgtk-3-dev libpulse-dev libpulse-mainloop-glib0 libusb-1.0-0-dev libgpiod-dev libi2c-dev

The GPIO devices are installed with root ownership. To be able to run as a user we create a '''gpio''' group that we can be a member of and also create a udev rule to create the gpio devices with a group id of '''gpio''' and set the permissions to read/write for the owner and group.

sudo addgroup --system gpio
sudo adduser $USER gpio

Create /etc/udev/rules.d/90-gpio.rules with:

KERNEL=="gpio*", OWNER="root", GROUP="gpio", MODE="660"

Edit /boot/firmware/config.txt and find the line with:

dtparams=spi=on

and change to:

dtparams=spi=off

I would recommend creating a directory '''github''' to download the source into:

mkdir github
cd github

Download the source:

git clone https://github.com/g0orx/wdsp.git
git clone https://github.com/g0orx/pihpsdr.git

cd ~/github/wdsp
make clean
make -j4
sudo make install

Copy libwdsp.so to the pihpsdr install directory:

cp libwdsp.so ~/github/pihpsdr/release/pihpsdr

cd ~/github/pihpsdr
make clean
make -j4
make release

cd ~
tar xvf ~/github/pihpsdr/release/pihpsdr.tar
cd pihpsdr
sh ./install.sh

To enable the Desktop short cut, Right mouse click on the icon created on the Desktop and select Allow Launching.