This is a small project to play around with embedded systems. The current idea is to use a Raspberry Pi 4 which is connected to a temperature sensor over I2C. The Pi will periodically read out the temperature from the sensor. This part of the project is programmed in C.
The Pi will also be connected to a laptop via an Ethernet cable. It will transmit the temperature to the laptop where it will be displayed graphically using a Qt C++ application.
- Can communicate between laptop and Pi using ZMQ.
- The hardware (temperature sensor, buzzer, jumper cables, breadboards) has been ordered.
- 2020-04-08: Create a Qt C++ GUI application: done
- 2020-04-09: Update graph axes on new data point. Send data from Pi to laptop and display on graph.
- 2020-04-10: Integrate ZMQ REQ/REP into main C++ program. Hope that hardware arrives.
- Create start/stop measuring button.
- 2020-04-11: Configure Buildroot to build a bootable RPI4 image.
- 2020-04-13: Test I2C on the RPI4
- 2020-04-14: Use Bosch BMP280 API to read out temperature.
- 2020-04-15: Cross-compile libzmq for linux-arm-gnueabihf
- 2020-04-16: Setup communication chain with static IPs disconnected a router. Fix I2C bug
- 2020-04-17: Port Raspberry Pi application to Buildroot. Use pressure data from sensor. Look into connecting buzzer.
- Toggle dtparam=i2c_arm=on in
/boot/config. This can also be changed with raspi-config. Note that this value needs to be dtparam=i2c1=on inbuildroot/package/rpi-firmware/config.txt
ioctl() is a Linux system call that stands for Input Output Control and is used for controlling hardware peripherals. It is for example used to control the volume of an audio device, for the configuration of a video device or for reading out device registers.
git clone https://github.com/zeromq/libzmq
cd libzmq
mkdir build_output
./autogen.sh
./configure --prefix=$(pwd)/build_output --host=arm-none-linux-gnueabi CC=arm-linux-gnueabi-gcc CXX=arm-linux-gnueabi-g++
make
make install