Design and development of a microcontroller based instruments

This project aims to help re-design an instrument for testing moisture content in foodgrains based on AT89C52 microcontroller to Atmel SAMD21 Cortex M0 microcontroller The analog design has been re-used from the previous working instrument. Working Principle: The resistance is measured by applying high voltage across foodgrain sample. The resistance of the food grains to the current depends on the moisture in it. Once the resistance is known, the moisture is measured using certain formula derived using graphical observation method. The high voltage is applied using a step up transformer and relays for a duration of around 7 seconds. The moisture result once obtained can be stored in internal memory, external USB pen drive or SD Card. The result can also be printed on a serial or Bluetooth Printer. All the process is controlled by a keypad and observed on a 16 x 2 LCD. Tasks completed till date, Interface of USB, SD Card, 16 x 2 LCD, 4 x 5 Hex Keypad, ADC and Relays has been done. Schematic design and PCB has been done and tested for a basic moisture reading accurately. Software framework for the menu flow has been done using state machines. Testing of USB, SD-Card interfacing and External I2C has to be done yet, Calibration code has to be completed. Storing the reading and retrieving from the memory has to be done. Battery management hardware is to be tested. Bluetooth and serial printing has to be completed. Integration of the modules has to be done. Code for menu driven operations has to be done . Freelancers from bangalore are preferred.