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Team:Cornell/project/drylab/components/electronics
From 2013.igem.org
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An overall picture of the LM34 temperature sensor system is illustrated below: | An overall picture of the LM34 temperature sensor system is illustrated below: | ||
<img src="https://2013.igem.org/File:Tempschematic.jpg"/> <br> | <img src="https://2013.igem.org/File:Tempschematic.jpg"/> <br> | ||
| + | The temperature sensor is hooked onto the A1 port of the microcontroller to allow the microcontroller to read data from the sensor. The microcontroller was programmed in C through the Arduino IDE to read the temperature every second. The program is designed as a feedback loop which decides whether to raise or lower the temperature based on the temperature input. Temperature is controlled by switching on or off the power loop. The microcontroller outputs a certain voltage based on the program, and that voltage (0 or 3.3V) will signal the transistor to switch on or off, either opening or closing the 6 V loop, which heats up the whole tank. <br> | ||
| + | The LM34 temperature sensor was chosen because it can read a wide range of temperatures to a 1.0°F accuracy, which is perfect for tuning the temperature of the incubator. Once the entire circuit was hooked up with the right components according to the schematic, measurements were taken to compare the temperature sensor with an actual thermometer’s readings. The temperature sensor was accurate to within 1°C, which was one of the requirements for the mushroom incubator. During the calibration, the temperature sensor reacted a lot quicker to temperature change than the actual thermometer. While the sensor and the thermometer were not placed in the same location by the resistor, they were close enough for this difference to be negligible. While doing this calibration, the change in voltage was recorded on the oscilloscope. Refer to the two diagrams in the Heating Circuit section to see the different options for heating by adjusting the duty cycle of the high to low voltage ratio. | ||
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Revision as of 02:34, 28 September 2013
Electronics
Temperature Sensor:
An overall picture of the LM34 temperature sensor system is illustrated below:
The temperature sensor is hooked onto the A1 port of the microcontroller to allow the microcontroller to read data from the sensor. The microcontroller was programmed in C through the Arduino IDE to read the temperature every second. The program is designed as a feedback loop which decides whether to raise or lower the temperature based on the temperature input. Temperature is controlled by switching on or off the power loop. The microcontroller outputs a certain voltage based on the program, and that voltage (0 or 3.3V) will signal the transistor to switch on or off, either opening or closing the 6 V loop, which heats up the whole tank.
The LM34 temperature sensor was chosen because it can read a wide range of temperatures to a 1.0°F accuracy, which is perfect for tuning the temperature of the incubator. Once the entire circuit was hooked up with the right components according to the schematic, measurements were taken to compare the temperature sensor with an actual thermometer’s readings. The temperature sensor was accurate to within 1°C, which was one of the requirements for the mushroom incubator. During the calibration, the temperature sensor reacted a lot quicker to temperature change than the actual thermometer. While the sensor and the thermometer were not placed in the same location by the resistor, they were close enough for this difference to be negligible. While doing this calibration, the change in voltage was recorded on the oscilloscope. Refer to the two diagrams in the Heating Circuit section to see the different options for heating by adjusting the duty cycle of the high to low voltage ratio.
