I am trying to create a way to more accurately measure product usage. I have variable speed augers dumping out material, DC motor drives the auger voltage range between 6-14V DC if I recall correctly.
What I am looking to do is have the voltage imputed to the board (indicating the flow rate), Then have how long its on that voltage recorded and turned in material use in pounds. So I will be needing some sort of display with it. Would like to have a way to stand alone calibrate it for different materials (Feed at different rates). Needs to keep counting up through multiple on off auger cycles, Then have a way to reset to do it again.
This is all way over my head and I am definitely looking for help on this and to know whether or not this is even feasible based off the arduino. Any and all input / help is greatly appreciated.
What voltage and current rating are the auger motors? If more than 5V and ~40mA, you need a motor driver shield.
Timing how long a specific PWM value is applied to the drive pin will only give you an approximate measure of the material moved. How accurate are you trying to be? +/- 10%? +/- 2%?
Hi, what you are trying to do is called "dosing" and measuring motor load will not give you an accurate measure of mass flow, apart from material, auger height and angle will influence load.
You need to measure the speed of the auger directly, this will give you a better reading of mass flow.
PaulS:
What voltage and current rating are the auger motors? If more than 5V and ~40mA, you need a motor driver shield.
Timing how long a specific PWM value is applied to the drive pin will only give you an approximate measure of the material moved. How accurate are you trying to be? +/- 10%? +/- 2%?
Then have a way to reset to do it again.
That would be a switch.
Defiantly going to need a shield then, Motors are at least 12V 50 amp (I'll have to check actual specs).
I am aware that it won't be 100% accurate, Not sure how far off it will be though. My guess is that it will be a lot closer than looking in the hopper and guessing at how much came out.
TomGeorge:
Hi, what you are trying to do is called "dosing" and measuring motor load will not give you an accurate measure of mass flow, apart from material, auger height and angle will influence load.
You need to measure the speed of the auger directly, this will give you a better reading of mass flow.
Tom........
I'm assuming actual accuracy is going to depend on a lot of different factors if I go with just the raw voltage applied to the motors correct? I was hoping to stay with raw voltage to keep this simpler and keep more delicate sensors out of harms way (near the augers).
79mb:
What I am looking to do is have the voltage imputed to the board (indicating the flow rate), Then have how long its on that voltage recorded and turned in material use in pounds. So I will be needing some sort of display with it. Would like to have a way to stand alone calibrate it for different materials (Feed at different rates). Needs to keep counting up through multiple on off auger cycles, Then have a way to reset to do it again.
Most of that seems feasible, but the relationship between motor voltage (or maybe pwm duty cycle?) and mass flow rate is likely to be difficult to work out accurately - the more accuracy you're asking for, the harder it will be to achieve. If you just want to know '30 minutes at full speed represents about 500 Kgs' type of accuracy then that ought to be easy enough, but this strikes me as the sort of approach that could easily end up with you struggling to get the results accurate enough to be useful. If there are any other options for determining flow rate - for example, measuring auger revolutions - that would give you a much better solution.
If you have a fixed set of materials to choose from then I'd pre-set the device with the calculation parameters for each material and use a rotary selector switch or similar to select the current material.
A push button to reset the counter would be very easy to implement. It might make sense to zero the counter if you change the material selection, too.
There are lots of ways to add a display to an Arduino. LCD shields are available which mount directly to the Arduino and include some push button switches which would give you an easy solution.
