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fabricademy2017:students:nuria.robles:week_9 [2018/05/12 00:15] nuriafablab_gmail.com |
fabricademy2017:students:nuria.robles:week_9 [2018/05/12 00:21] nuriafablab_gmail.com |
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Create an interactive object; if you are already experienced with coding, focus on fully integrating a microcontoller into a textile circuit. If you are new to coding, choose an example and get it working using your own sensors and actuators. | Create an interactive object; if you are already experienced with coding, focus on fully integrating a microcontoller into a textile circuit. If you are new to coding, choose an example and get it working using your own sensors and actuators. | ||
+ | |||
+ | ---- | ||
+ | |||
+ | === Digital Sensor Circuits === | ||
+ | |||
+ | A **digital sensor** is an electronic or electrochemical sensor, where [[https://en.wikipedia.org/wiki/Data_conversion|data conversion]] and data transmission are done digitally. | ||
+ | |||
+ | When a digital sensor is connected to a microcontroller, need to use a pull down or pull-up resistor. A nice tutorial about pull-up, pull-down resistor can be found [[https://learn.sparkfun.com/tutorials/pull-up-resistors|here]]. | ||
+ | |||
+ | === Reading Resistive Sensors === | ||
+ | |||
+ | The first thing I want to test is how my crochet pressure sensor acts in a voltage divider. Many sensors in the real world are simple resistive devices. A [[https://www.sparkfun.com/products/9088|photocell]] is a variable resistor, which produces a resistance proportional to the amount of light it senses. Other devices like [[https://www.sparkfun.com/products/8606?|flex sensors]], [[https://www.sparkfun.com/products/9375|force-sensitive resistors]], and [[https://www.sparkfun.com/products/250|thermistors]], are also variable resistors. | ||
+ | |||
+ | It turns out voltage is really easy for microcontrollers (those with [[https://learn.sparkfun.com/tutorials/analog-to-digital-conversion|analog-to-digital converters]] - ADC’s - at least) to measure. Resistance? Not so much. But, by adding another resistor to the resistive sensors, we can create a voltage divider. Once the output of the voltage divider is known, we can go back and calculate the resistance of the sensor. | ||
+ | |||
+ | For example, the photocell’s resistance varies between 1kΩ in the light and about 10kΩ in the dark. If we combine that with a static resistance somewhere in the middle - say 5.6kΩ, we can get a wide range out of the voltage divider they create. | ||
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=== === | === === | ||
- | === Digital Sensor Circuits === | + | === === |
- | + | ||
- | A **digital sensor** is an electronic or electrochemical sensor, where [[https://en.wikipedia.org/wiki/Data_conversion|data conversion]] and data transmission are done digitally. | + | |
- | + | ||
- | When a digital sensor is connected to a microcontroller, need to use a pull down or pull-up resistor. A nice tutorial about pull-up, pull-down resistor can be found [[https://learn.sparkfun.com/tutorials/pull-up-resistors|here]]. | + | |
- | + | ||
- | === Reading Resistive Sensors === | + | |
- | + | ||
- | The first thing I want to test is how my crochet pressure sensor acts in a voltage divider. Many sensors in the real world are simple resistive devices. A [[https://www.sparkfun.com/products/9088|photocell]] is a variable resistor, which produces a resistance proportional to the amount of light it senses. Other devices like [[https://www.sparkfun.com/products/8606?|flex sensors]], [[https://www.sparkfun.com/products/9375|force-sensitive resistors]], and [[https://www.sparkfun.com/products/250|thermistors]], are also variable resistors. | + | |
- | + | ||
- | It turns out voltage is really easy for microcontrollers (those with [[https://learn.sparkfun.com/tutorials/analog-to-digital-conversion|analog-to-digital converters]] - ADC’s - at least) to measure. Resistance? Not so much. But, by adding another resistor to the resistive sensors, we can create a voltage divider. Once the output of the voltage divider is known, we can go back and calculate the resistance of the sensor. | + | |
- | + | ||
- | For example, the photocell’s resistance varies between 1kΩ in the light and about 10kΩ in the dark. If we combine that with a static resistance somewhere in the middle - say 5.6kΩ, we can get a wide range out of the voltage divider they create. | + | |