Possible to have an external power source for moisture sensors??

[mrhutchinsonmn]

I want to run 6 analog moisture sensors on a single arduino nano(if possible). I am guessing that may cause erratic behavior from power issues. Is there a way to use an external power source and still provide a connection to the nano, like is done with a jd-vcc pin on my 8 channel relay, so the sensor will work correctly?

[mrhutchinsonmn]

@mrhutchinsonmn Did some more research. It seems it is possible to run all 6 sensors on a single board without a 2nd power source since readings are not taken simultaneously. Is that a correct assertation?

[mfalkvidd]

I don’t see why it wouldn’t work, but on the other hand I don’t see the original problem either.

[mrhutchinsonmn]

@mfalkvidd I was looking at it through the perspective of my 8 channel relay which needs an external power source to work reliably. Seems 6 moisture sensors will work fine.

[mfalkvidd]

@mrhutchinsonmn yes. Relays draw a lot of power when switching. Moisture sensors draw almost no power.

[skywatch]

@mrhutchinsonmn So long as the ground wires are all connected together you should be fine.

But before you do a lot of work, search on here about moisture sensors, it might save you a lot of time.

[gieemek]

I have MySensors node with 5 moisture sensors - work without problems for one year.
Node platform:

• Arduino Pro Mini 5 V
• RFM69HCW powered by 3,3V voltage regulator + resistors on communication lines
• 5x FDRobot moisture sensors
• 3x DS18B20 temperature sensors

powered by 5V, 1A power supply