# Lecture notes
Digital - Either 0 or 1
Analog - Read voltage

rule of thumb for signal measuring. At least sample at double the frequency that is being sampled from the sensor.  

![alt text](image.png)

GPIO

Low - 0 to 1/3 vcc
High 2/3 to 1 vcc



Signal from a DHT

![alt text](image-1.png)

![alt text](image-2.png)

![alt text](image-3.png)
ds18b20


![alt text](image-4.png)

![alt text](image-7.png)