iotMW

The IoT based Microwave is built as a device to provide measured heating for industrial applications

The project is a temperature controlled microwave, for use in bakeries etc. which rely on precise heating setups, while conventional microwaves provide only timer based heating

Code for the hardware fit to run on a Raspberry PI can be found on https://github.com/harshvs99/iotMW

Design

The iotMW works to provide a calibrated temperature sensor, stopping only at specified temperatures.

• Peripheral TFT and Buttons: Added using the SPI protocol using an FSM diagram for flow control

• Temperature Offsets: With rigrous testing, we calculate offsets and builds on it for sensor translation of the algorithm based on input data

Temperature Offsets

The primary work behind the project has been to develop comprehensive temperature offsets based on sampling statisitics

• The algorithm considers variables such as room temperature and body temperature of the microwave + magnetron to configure for more accurate shifts in temperature

• I use unbiased sample estimators to derive for the true variance allowed in the data for a variety of data points at different temperature marks

High Temperature

For higher temperatures we have a straightforward means of achieving our desired temperature, since our application is for baking appliances a variance of +- 5K does not effect its utility so we progressively keep heating until the desired temperature is reached

Cold Temperature

For cold temperature defrosting, the temperature gradients have to be observed a lot more closely since defrosting too quickly might spoil the bakery product being defrosted and make it unfit for use. Heating is observed in slow increments, where when the temperature reaches within 10K of the desired temperature the magnetron is switched on in pulses to observe single degree changes. The process allows for a variance of less than +- 1K