Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Both sides previous revision Previous revision
Last revision Both sides next revision
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
Line 18: Line 18:
  
 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.
  
 ---- ----
Line 300: Line 316:
 ===   === ===   ===
  
-=== 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.+