Sensors visited or revisitied
- 1 short plan
- 2 Sensors
- 3 More sensors:
- 4 Rapid assignment
10:00-11:00 we talk a bit and check in with each other / checking kits
11: 00 - 11:45 everyone chooses a sensor and gets it running
11:45 - 12:00 smoke break
12:00 - 12:30 lunch
12:30 - 14:00 work on the machines
14:00 - 14:30 everyone makes a short demo of their prototype
Analog sensors on the other hand, gives range. You connect this types of Analog sensors to Analog Input pins which is measuring the incoming voltage between 0V-5V*. Arduino converts this incoming voltage into the number between 0-1023.
Analog data is transmitted as a continuous signal, almost like a wave. In other words, an analog sensor doesn’t send a burst of 1s and 0s like digital sensors do; instead, the sensor modulates a continuous signal to transmit data.
Microcontrollers are capable of detecting binary signals: is the button pressed or not? These are digital signals. When a microcontroller is powered from five volts, it understands zero volts (0V) as a binary 0 and a five volts (5V) as a binary 1. The world however is not so simple and likes to use shades of gray. What if the signal is 2.72V? Is that a zero or a one? We often need to measure signals that vary; these are called analog signals. A 5V analog sensor may output 0.01V or 4.99V or anything inbetween. Luckily, nearly all microcontrollers have a device built into them that allows us to convert these voltages into values that we can use in a program to make a decision.
An Analog to Digital Converter (ADC) is a very useful feature that converts an analog voltage on a pin to a digital number. By converting from the analog world to the digital world, we can begin to use electronics to interface to the analog world around us.
Not every pin on a microcontroller has the ability to do analog to digital conversions. On the Arduino board, these pins have an ‘A’ in front of their label (A0 through A5) to indicate these pins can read analog voltages.
ADCs can vary greatly between microcontroller. The ADC on the Arduino is a 10-bit ADC meaning it has the ability to detect 1,024 (210) discrete analog levels. Some microcontrollers have 8-bit ADCs (28 = 256 discrete levels) and some have 16-bit ADCs (216 = 65,536 discrete levels).
The knob example (hello world)
Good read to go in detail about voltage dividers HERE
Digital sensors are the sensors that gives 2 state (on/off, 5V/0V). You connect them to digital Pins and set them as INPUT.
Digital data consists exclusively of 0s and 1s .
For example, consider a push button switch. This is one of the simplest forms of sensors. It has two discrete values. It is on, or it is off. Other 'discrete' sensors might provide you with a binary value.
Another example of a digital sensor is an accelerometer, which sends a series of data points (speed, direction, and so on) to the Arduino. Usually digital sensors need a chip in the sensor to interpret the physical data.
Ultrasonic distance sensor
We need to install additional libraries.
Ultrasonic Sensor - HC-SR04
resistive sensors form a voltage divider together with a 10kΩ ground.
Swapping over the resistor and sensor The resistor and sensor can be swapped over to invert the action of the Voltage divider. For example an LDR has a high resistance when dark and a low resistance when brightly lit, so:
If the LDR is at the top (near +Vs), Vo will be low in the dark and high in bright light.
If the LDR is at the bottom (near 0V), Vo will be high in the dark and low in bright light.
Pulse sensor(heart rate):
Soil Moisture Sensor:
SparkFun Soil Moisture Sensor
UV sensor: uv-index-sensor
Use a sensor and an output of your choice to build a machine/object that does not exist and may not fulfil any utilitarian function