Circuit Board

Circuit diagram

The circuit board basically consists of a socket for the Pico W and external and internal connectors. There are internal screw connectors for the servo pumps; balance display, amplifier and tare button; and an emergency STOP button. There are external connectors for 5VDC power (10 amp), temperature sensor, heating element, auxiliary 5VDC power, stirrer jack, and two Experiment Module connectors.  The Pico W also provides a micro USB connector, which is accessible through the panel. There is also a resistor for the temperature sensor, and a diode for supplying power to the Pico W. There are two power relays for the heating element and auxiliary 5VDC power controlled by output pins from the Pico W. The hope is to someday design a PCB for lab kit.