t3rmian / rpidemo Goto Github PK

This repository currently contains a demo for reading relative humidity and temperature from DHT11 using pi4j-library-pigpio. The solution is based on the pigpio alert function and is fairly robust. It does not suffer from missed reads. Root privileges are required for GPIO access. Read more on https://blog.termian.dev/posts/dht11-java-pi4j-pigpio

./mvnw clean install
# run on RPI
sudo java -jar -DDHT11_GPIO=21 target/rpidemo-1.0-SNAPSHOT-jar-with-dependencies.jar

Besides the program, there are also some JIT JMH tests that verify whether polling times for pi4j-core and pi4j-library-pigpio are acceptable as a potential alternative. There is also a GraalVM configuration that builds a crude native executable to get the feeling of timings for AOT compilation (can be build on OCI).

# run on OCI aarch64
./mvnw clean install -Pnative
# run on RPI
sudo target/rpidemo -Dpi4j.library.path=/path/to/unpacked/pi4j-library-pigpio-2.3.0.jar!lib/aarch64/