This is Thor again, back with some more summer news! Since the last post, it has been a little slow because of waiting for the order to arrive so I can assemble the new boards. Last week I was able to have the Arduino control the successful login sound and light. I have now coded an unsuccessful sound and light. All it does it beep and blink red, but the Arduino is able to read in a string sent serially by the Pi. If the Arduino reads in “login”, then the successful code runs and if it reads in “error”, the other code runs. This way, we can have different sounds and lights set up to execute at different times when certain actions occur. The Pi can sent string serially and then continue on with the code while the Arduino takes care of the light and sound. This will prevent interruptions in the Pi code so the keypad can function at a fast pace. On the new PCBs, we have the serial connection between the TX (transfer) and RX (receive) pins on the Pi and Arduino. They will have to be tested when we assemble them because I was only testing the connection over a USB cable. Only the RX from the Arduino and the TX from the Pi are going to be connected, so that the Pi can send strings to the Arduino. We do not need to send anything back to the Pi. The Arduino also runs on 5V logic while the Pi runs on 3.3V logic. The Arduino can handle and understand the 3.3V signals coming in from the Pi but vice versa would need a voltage divider. To simplify the hardware, we are not going to have the Pi receive anything back from the Arduino for now.
Once the shipment of parts arrives, we can assemble them and hopefully our devices work the way we intended so we can begin installing them on machines if time permits.
Until next time!