LinuxDeviceDrivers

Device tree based driver for a common cathode seven-segments display. To run this module in any embedded dispositive you should modify the device-tree overlay file, this repository shows an overlay example for the raspberry pi single board computer family.

Raspberry Pi pinout

The relation between the Raspberry Pi GPIO pins and the display segments is:

  SEGMENT | HS-3161 PIN | GPIO
     a    |     10      |  2
     b    |     9       |  3
     c    |     8       |  4
     d    |     5       |  5
     e    |     4       |  6
     f    |     2       |  7
     g    |     3       |  9
     dp   |     7       |  10

Driver files

The driver files are located at /sys/class/7segment repository. If you write a number from 0 to 9 in the value file the display will show this number, for numbers higher than 9 the display will show the character "E" from error. If you write 0 and 1 in the enableDP file, the dot will respectively light off and light on. Writing numbers higher than 1 in the enableDP file shouldn't change anything at the display.

To enable/disable the module

To enable the module in rasbian you should:

make

sudo dtoverlay overlay.dtbo

sudo insmod 7segment.ko

To disable the module in raspbian you should:

sudo rmmod 7segment