CODEWITHSUNDEEP
javaraspberry-pigpioraspberry-pi4
John A.
John A.

Reputation: 31

Raspberry pi 4 controle GPIO with java

I want to controle a 16*2 lcd display on my raspberry pi4 with java. The problem is that Pi4J - the solution to modify the gpios with java is not updated to pi4. Is there another solution? This error occures when I start the programm:

pi@raspberrypi:~/desktop/gpio $ sudo ./start.sh

<--Pi4J--> GPIO Control Example ... started. Maista Unable to determine hardware version. I see: Hardware : BCM2711 ,

Upvotes: 3

Views: 1756

Answers (3)

Andres Perez
Andres Perez

Reputation: 46

I found out the reason it was not working for me, is that sudo dpkg -i wiringpi-latest.deb installs gpio in /usr/bin/gpio but there was another gpio file in /usr/local/bin/gpio which was taking precedence. You can find if this is the case for you by running which gpio.

I renamed the old file from gpio to gpio.old (I did not want to delete it, just in case) and executed sudo dpkg -i wiringpi-latest.deb again. Now when I run which gpio I find the correct executable.

Upvotes: 0

Frank
Frank

Reputation: 6687

Pi4J uses WiringPi to control the GPIOs. So please update it to version 2.52 as this one supports the Raspberry Pi 4, see http://wiringpi.com/wiringpi-updated-to-2-52-for-the-raspberry-pi-4b/

$ gpio -v
gpio version: 2.50
$ cd /tmp
$ wget https://project-downloads.drogon.net/wiringpi-latest.deb
$ sudo dpkg -i wiringpi-latest.deb
$ gpio -v
gpio version: 2.52

You can find a full java+pi4j+lcd example on my blog on https://webtechie.be/post/2020-01-26-openweathermap-forecast-on-lcd-with-raspberry-pi-java-and-pi4j/

Upvotes: 5

Otid0
Otid0

Reputation: 269

I found this that can help you. It seems easy to understand, you just need to change some xml files.

Upvotes: -1

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