Use 4 Raspberry Pi GPIO Lines for your own needs


There are two GPIO inputs used for switches and two GPIO outputs used to drive LEDs on the Sonar Board. If you do not use the Sonar board OR are willing to sacrifice the features these lines support for Magni Silver and Magni Gold here is the information required.

Look for and perhaps use P704 and P705 jacks after disabling the usage of these by Magni. Normally those 2 jacks and their Magni usage AND two other GPIO pins used to drive LEDs that exist on the Magni ‘Sonar Board’ are controlled by Magni.

GPIO RasPi Pin Default Magni Usage
5 29 Status LED on the sonar board
25 22 Status LED on the sonar board
6 31 Goes to P704 pin 2. Does a shutdown when grounded. This goes to a pushbutton on Sonar Board neqar 50 pin connector.
13 33 Goes to P705 pin 2. Used for PiFi and goes to a pushbutton on the Sonar Board

To use these as GPIO you must edit /etc/pifi/pifi.conf:

Pifi should still work but you would not get LED indication or be able to use the button that is used with PiFi

To be able to drive the 2 LEDs on the sonar board yourself or just use GPIO 5 and 25 when there is no Sonar Board you will need to edit /boot/config.txt and comment out ‘dtoverlay=ubiquity-leds-buttons’

Doing both of the above changes frees up the 4 GPIO lines for your purposes and you should also configure them as your application requires.

GPIO lines 6 and 13 go to some 3-pin jacks, P704 and P705, where pin 1 is ground and short to pin 2 to ‘close’ or make that GPIO line low. Pin 3 of those jacks is 3.3 volts if you need that for your sensors. Do not short this to ground! Pin 2 of P704 and P705 goes directly to Raspberry PI GPIO so do NOT connect to 5V because it is for 3.3Volt maximum input.

GPIO Lines Used For Sonar Board

There are many other GPIO lines used for the sensor board shown the table below:

GPIO Pin Comment
20 38 Sonar 0 Trigger
21 40 Sonar 0 Echo
12 32 Sonar 1 Trigger
16 36 Sonar 1 Echo
23 16 Sonar 2 Trigger
24 18 Sonar 2 Echo
27 13 Sonar 3 Trigger
22 15 Sonar 3 Echo
19 35 Sonar 4 Trigger
26 37 Sonar 4 Echo