We managed to achieve a lot of things during this week.
- The whole hardware has been integrated into a wooden box, mostly to avoid any risks with the wires. Even if a PCB was made to reduce the amount of cables needed, there are still a lot of them.
- The PT100 temperature reading was already working, but the resolution was very poor: 2.5 °C. It was due to the fact that the voltage change was very low, too low for the analog input of the Arduino (0-5V for 1-1023 bit). To resolve this issue, an amplifier is used to multiply the voltage across the PT100 by 8. This way, the resolution went from 2.5 to less than 0.5 °C, which is just enough considering the goal of our project.
- The LCD screen part was (connected to the Arduino) completed. It allows to display the current temperature and the current setpoint, which can be changed via a potentiometer.
- With both the LCD screen and PT100 working, we were able to complete the Arduino part of the project. The whole system can be driven by it.
- The communication between the Raspberry-database-website-Arduino is still in progress, but it should be done next week!
Our project is nearly finished. We still need to make a final test, but it shouldn’t take too long !