Development of Variable Rate Fertilizer Applicator ModuleBased on 8-bit Embedded System

Abstract

Variable rate technology (VRT) is one of crucial component in precision farming implementation, and is now gaining popularity and widely accepted as one of smart solutions to sustain agriculture production without ignoring environmental impact. With VRT machines, the dose and the position of application could be given precisely as required by crops. Machinery with variable rate capabilities impressed as technologically sophisticated and expensive. In Indonesia, implementation of VRT in crop production is also still questioned, because fear of the complicated and expensive prices of the machines. Therefore, the objective of this research was to develop a prototype smart applicator to perform variable rate fertilizer application suitable for rice cultivation in Indonesia. Simple mechanism which result an affordable price of the machine will be considered in prototype. Therefore, to control the desired dose of application a rotor type metering device was chosen because it has simple mechanism since it could be directly powered by DC geared motor. In this study, the range of speed control is about 30 to 90 % of motor performance. Digital control with PID compensator was used in this system. Embedded system base on 8-bit micro- processor was adopted since it was cheap and available in the local market. The control module is developed based on this embedded system, where I2C (inter integrated circuit) communication protocol was used for hardware-software interfacing using C language programming. This paper will discussed bench test results of motor control. For field operation in the future, the developed VRT applicator will be mounted on multi-purpose vehicle which was modified from riding type rice transplanter. Position of the vehicle in the field will be acquired using agriculture type RTK DGPS.