The smart water dispenser uses for R3 development board as the main control board. Equipped with exclusive expansion board and PH2.0 sensor, it avoids messy wire connection, makes the project easier and faster to build, assembly and wiring are relatively simple, and the performance is more stable! This kit can achieve:Potentiometer controls water discharge time, touch switch starts water pump, button emergency stop and LED light working indication. At the same time, the water discharge time is displayed through a four-digit LED digital tube. In this smart water dispenser, we use a potentiometer to control the water discharge time. By adjusting the knob of the potentiometer, you can choose the length of the water discharge time. Use switch to start the water pump. When the touch switch is touched, the circuit start the water pump to start discharging water. In addition, a button is also provided to perform an emergency stop function. When the button is pressed, the water pump stop working immediately. At the same time, there is an LED indicator to display the working status of the water dispenser. Compatible development board: for development board Basic input module: rotary potentiometer x1 Actuator: relay module x1, LED light module x1 Display: four-digit LED digital tube x1 Expansion board: --EXP2 Power module output: maximum 5V/800MA Power interface input voltage range: 6-12V Power supply method: 1. Use TYPE-C USB port power supply voltage (5V); 2. Use power port power supply voltage (DC7V~12V) Others: onboard custom function button x1, spare expansion interface x1 Supported programming software: for IDE, for Mixly, for Ardublock, for Scratch Colour:Wood color Material:Wood + Electronic Components 2 AAA batteries not included Package Contents: 1 x Smart Water Dispenser DIY Kit with for R3 Development board (This is a DIY kit, you need to assemble it yourself) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.