Hi! I am working with this project:
which is great and uses 2 nails connected to ‘0’ and ‘3V’ on the micro:bit but I am wondering if its possible to do this with just 1 nail? If yes, where would the nail be connected to and would the code change? Thanks!
The code in the example is using analogRead()
, which reads the voltage on the P0
nail and compares it to the 3 volts from the 3V
nail.
Here’s a way to think about it: The 3V
(they use P1
at the end) “puts” three volts into the soil. The P0
measures how much of that 3 volts was “lost” as it travelled through the soil to the P0
nail. It is doing a comparison (somewhat like subtraction) to see how much it’s changed…it needs both the “start” (3V
) and end (P0
) to do the comparison needed here.
If you haven’t studied voltage and current before, you might take a look at some tutorials. I like SparkFun’s: Voltage, Current, Resistance, and Ohm’s Law, which has a few videos that may help.
Bill
1 Like
Hey!
I was working on a similar project and ended up making a video for it.
As mentioned you will need to measure the current flowing between two probes (hence the two nails). Using a ready made gives better contact and more sensitivity though it can definitely be done without.
Micro:bit self watering
WOW love this, will take a look now!