In this adventure the Arduino Hero Toolbox has a run in with a different kind of meter than it is used to…
The antagonist of this story rises as a Hartmann & Braun type portable 60 ampere gauge. Looking inside we find the meter mechanism and a fairly large coil. The coil consists of four double wires with 16 loops each.
The antagonist is of the type Moving Iron. Moving iron meters are non-linear, require a lot of power and are difficult to get accurate. A real bad guy. First step is to replace the coil with one with more windings, so less current is needed. Another appearance of the 3D printer (from another universe) prints the two parts of the coil. Model for that is on GitHub repository. Time for our Arduino Hero Toolbox to step in! Counting the turns made by Ms. Windy the converted sowing machine is right up his sleeve.
DISASTER! The carefully hotglued base for the coil comes apart during winding! Luckily C.A. Glue does a better job, and winding soon resumes. Extra space in the base of the original gauge is needed to house the new coil, so fierce grinding ensued.
Next step is to put it together, and to change the plate. Some clonestamping zero’s out later, and a new plate is born. The plates are also on the GitHub repo.
A mounted plate is finished. But the Arduino Hero Toolbox has no time to rest. He needs the help of some components to drive the new setup. Locating these in the
leftover parts bin asteroid belt of the planet BOX, he gets to work to determine the correct PWM values corresponding to values on the plate.
A very professional looking calibration table follows. Arduino code is on GitHub repo. After that a helpful bystander in the form of the Iduino ME110 moisture sensor is called in. Together with the Arduino and helper parts they try to see if they can get the gauge under control.
Unfortunately here the helpful separates it’s legs from it’s brain. With the help of a sharp-eyed onlooker a piece of oak is transformed to a new pear of feeler legs, and quickly united through electric cable to the other half. A perf board is snatched from a
drawer asteroid flying by.
The antagonist is put back into it’s place and surrounded by it’s original prison. With the arduino inside it controlling it’s every movement. That ought to teach him! Even though, either the plant is alive, or the meter is trying to escape….