We have already seen till now how we have constructed our project in PCB .
Liquid filler at this point needs calibration.
In this article we will discuss the calibration method.
The first step is to dimension correctly the RG resistor.
From the weight sensors article we already know that :
a) For a 1Kg load cell we are going to need Gain=1,07421875/0,005473=196 for a 1.1V arduino reference analogReference(INTERNAL); So we need a Rg=312 Ohm.
b) For a 20Kg load cell we need a Gain = 3925 for a 1.1V arduino reference analogReference(INTERNAL);
So we need a Rg=15 Ohm.
In the last two articles we have worked on the breadboard.
We have seen that the circuit worked well so we need to construct it in PCB and then calibrate it.
We will start with the KiCad schematic file and then we will see the PCB layout.
Then we will construct a weight board with the load cell installed on it.
Once done with this step then we should be able to calibrate the device.
The calibration will be discussed in a next article.
In the first part of liquid filler we have made the user interface.
LCD buttons and circular menu were made.
Now it is time to add the relay and the weight sensor.
We will keep working on our breadboard.
In this article we will see how to connect the relay then our load cell amplified by the INA125 and lastly the modified code from the last time.
Liquid filler will be our first complete project here at hw2sw! 😎
We have made a series of articles that we will use in order to reach our goal.
Liquid filler is exactly as its name says, an really cheap but accurate liquid filling machine.
We need to auto-fill bottles with a certain capacity (50 up to 8500gr).
This arduino based project will permit to fill all containers with a certain, user defined, weight limit.
So the machine works on weight base and not on volume, flow or pressure base like other fillers.
Other than the machine you see in the photo, you need a weighting board that the bottle will sit on and a gravity feed valve that is piloted by liquid filler.
The present solution will weight containers up to 8,5 Kg.