Lucky Resistor
Menu
  • Home
  • Learn
    • Learn C++
    • Product Photography for Electronics
      • Required Equipment and Software
    • Soldering for Show
  • Projects
  • Libraries
  • Applications
  • Shop
  • About
    • About Me
    • Contact
    • Stay Informed
  •  
Menu

Plant Watering Sensor – Precise Current Measurement

Posted on 2017-02-242017-02-24 by Lucky Resistor

As I wrote in the first part of my article, how to design a cheap plant watering sensor, I had troubles to get exact measurements of the current, using my Testo multimeter. I searched for a solution and found the µCurrent Gold device, from David L. Jones known for the EEVblog. Later a little bit more about the device, first the measurements.

plantsensor-current-1

I could do the measurements using the oscilloscope and not only measure the static current consumption, but the current consumption over time. The graph shown in the diagram, is the reading of if the sensor does one single measurement and flashes the LED.

The range of the device for the µA region is limited to 1250µA with the 3V coin cell I use, so the current consumption of the LED is way out of range. This is no problem, because  is very easy to measure this much larger current using the multimeter. I did not measure it yet properly, but it will be 20mA or less, therefore I just assume the worst – 20mA for this part.

plantsensor-current-2

Now I can do a rough estimation of the real power consumption. Without the LED flash, it is just 56µAs (this is ~15nAh). With a single flash, it is much higher with 956µAs (~0.26µAh). Using these values, I can easily calculate the battery life for normal operation.

µCurrent Gold

This simple device just converts the measured current into a voltage, which can easily measured using a multimeter or as I did, using a oscilloscope.

lucky-resistor-1

The clever design of this device reduces the burden voltage into the µV range (10-20µV). Read all details about the device here:

µCurrent Gold

In a few days I will publish the 3rd part of my article, with details about the PCB prototype and the start of the final design.

If you have any questions, corrections or miss some information, please do not hesitate to leave a comment below.

Leave a Reply Cancel reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Stay Updated

Join me on Mastodon!

Top Posts & Pages

  • Storage Boxes System for 3D Print
  • Event-based Firmware (Part 1/2)
  • Build a 3D Printer Enclosure
  • Yet Another Filament Filter
  • Circle Pattern Generator
  • Circle Pattern Generator
  • Real Time Counter and Integer Overflow
  • Projects
  • Logic Gates Puzzle 11
  • Units of Measurements for Safe C++ Variables

Latest Posts

  • Better Bridging with Slicer Guides2023-02-04
  • Stronger 3D Printed Parts with Vertical Perimeter Linking2023-02-02
  • Logic Gates Puzzle 1012023-02-02
  • Candlelight Emulation – Complexity with Layering2023-02-01
  • Three Ways to Integrate LED Light Into the Modular Lantern2023-01-29
  • The 3D Printed Modular Lantern2023-01-17
  • Rail Grid Alternatives and More Interesting Updates2022-12-09
  • Large Update to the Circle Pattern Generator2022-11-10

Categories

  • 3D Printing
  • Build
  • Common
  • Fail
  • Fun
  • Learn
  • Projects
  • Puzzle
  • Recommendations
  • Request for Comments
  • Review
  • Software
Copyright (c)2022 by Lucky Resistor. All rights reserved.
 

Loading Comments...