SPI1
The Pi-Tron has the same GPIO header as the Raspberry Pi B(+) models. Since the SPI 0 bus is intended to be used for the CAN bus function of the Pi-Tron, the SPI 1 bus can be used instead.
1. Update Raspberry Pi OS
pi@raspberry:~ $ sudo apt-get update
pi@raspberry:~ $ sudo apt-get dist-upgrade
2. Edit the config.txt
pi@raspberry:~ $ sudo nano /boot/config.txt
Enter the following at the end of the file:
### SPI 1 interface with 3 chip enable/chip select signals
dtparam=spi=on
dtoverlay=spi1-3cs
Save the changes.
3. Reboot
pi@raspberry:~ $ sudo reboot
4. Check for SPI1
After the reboot there should be 3 new SPI devices in the /dev/
folder. It should be spidev1.0
to spidev1.2
.
pi@raspberry:~ $ ls -la /dev/spidev1*
crw-rw---- 1 root spi 153, 3 Feb 14 2019 /dev/spidev1.0
crw-rw---- 1 root spi 153, 2 Feb 14 2019 /dev/spidev1.1
crw-rw---- 1 root spi 153, 1 Feb 14 2019 /dev/spidev1.2
The SPI 1 bus is located on the GPIO header at:
Pin number | GPIO name | GPIO description |
---|---|---|
12 | GPIO18 | SPI1 CE0 N |
11 | GPIO17 | SPI1 CE1 N |
36 | GPIO16 | SPI1 CE2 N |
35 | GPIO19 | SPI1 MISO |
38 | GPIO20 | SPI1 MOSI |
40 | GPIO21 | SPI1 SCLK |