This site will give instructions on how to build and calibrate the required electrical systems for the Agribot Project. Each device will have its own page of instructions and a brief explanation of how the system works.
A brief introduction to working with the basics like Breadboards, Resistors and the Arduino IDE before building any systems.
To measure the water level in the tank an ultrasonic sensor was one of the possible options for measuring the level. The distance between the sensor and the water is measured using a HC-S04 and that data is passed to an Arduino Nano and used to calculated the level of water left in the tank.
To measure the water level in the tank an using a pressure sensor. Using the Honeywell 24PC pressure sensor series to find the pressure in the tank and calculate the volume of water in the tank.
To measure the weight water in the tank an using a ARD2-2151 load cell sensor. Different weights were used to demonstrate the function of the load cell and display the voltage input values and the weight of water the tank in milliliters.
To measure the ambient temperature, the system was designed around the PT100 RTD. It is converted to a voltage using a wheatstone bridge and amplified to a 0 - 5V range using an lm324 to make the most use of an Arduino Nano's A/D input range. The Nano is used for A/D conversion and re-scaling of units to output a temperature reading in deg C
To measure the ambient temperature, another temperature sensor that could be used is the NTC Thermistor. The resistors for the wheatstone bridge is calculated aswell as the input resistance for the lm324 amplifier and the feedback to give the gain of 5.