Author Topic: Digispark USB Development Board Analog Input  (Read 880 times)

aand

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Digispark USB Development Board Analog Input
« on: December 03, 2016, 12:01:36 pm »
I'm using a 4-digit seven segment led and a sunkee soil moisture sensor on a digispark attiny85 usb development board.  I'm using the Arduino ide to program the attiny85, and I have things working, kind of.

I have two questions:

1. Is the max voltage input 3.3v or 5v?  Do I need a voltage divider if input is ~5v or am I okay as-is?

[spoiler]The sensor I'm using is like this:
https://www.amazon.com/SUNKEE-Soil-Hygrometer-Moisture-Sensor/dp/B00AYCNEKW/ref=sr_1_3?s=industrial&ie=UTF8&qid=1480794195&sr=1-3&keywords=soil+moisture+sensor
[/spoiler]

2. I'm reading the soil moisture sensor analog input on P2 analogRead(0), but readings seem flipped.  In dry air it reads ~1016.  In water it reads ~275.  Is this correct?  I may have to adjust my thinking.

This is new to me, so I will not be insulted by any comments.
Thanks!