[SOLVED] Setting the ports of the GrovePi Zero

grovepi-zero
ports
faq

#1

First, excuse me. I’m very much a beginner.

I’m trying to use a GrovePi Zero with a display module, humidity/temp sensor module, and a Grove Relay module.

I see only one port reference as a digital port, which is where I have the humidity/temp module. The examples I’ve seen using the relay module show this also being plugged in to a digital port.

I read on another thread that analog ports can be used as digital ports. Can someone elaborate on how this works and what I need to know to make this work. The end goal is to trip the relay when humidity or temps come out of a certain range.

Thank you


#2

Hi @jeremy,

Here’s a drawing of the GrovePi Zero.

Take a look at the markers and see that there are a couple of ports that can act as digital ports.
Here’s a short description of each port’s mode:

  • Port A0 - can be either set as an analog port or digital port.

  • Port A1 - can be either set as an analog port or digital port.

  • Port A2 - can be either set as an analog port or digital port.

  • Port D3 - can be only be set as a digital port.


In order to use a given port as a digital port, you need to use the digitalWrite or digitalRead function.
On the other hand, in order to treat a port as an analog port, you need to use the analogRead or analogWrite functions.


For using a DHT module (that’s the temperature + humidity sensor), you only need to use the dht function.
Take a look at the Home_Weather_Display project and see what I mean about the DHT sensor.

For giving you a rough idea, here’s how I would do the wiring:

  • DHT sensor to port D3.

  • And a Relay to port A2.


Please let us know if this was helpful for you.
If there are other questions, please let us know.

Thank you!


#3

Thank you for the detailed explanation. So it basically just comes down to the function you call as to whether it’s treated as digital or analog. Perfect.


#4