hello, I'm looking for help on how to set up an Arduino to get two pieces of information from a cement silo system. Ultimately I'm trying to use a single channel hall effect sensor to pick up counts on the drive cog of the cement delivery auger, but id like to have the Arduino track time from the first signal or moment of rotation to when the cog stops turning. I'm doing this to calibrate a VFD motor that is on the silo to know how much powder is dispensed at different percentages and ultimately time- Lbs/count and counts/time. I know a fair amount when it comes to analog electronic, if it was something my grandpa would have dealt with I can usually figure it out. But this Arduino and code thing is new to me so id appreciate anyones guidance as I see using these types of devices very useful in my industry and id love to learn and get more familiar with them. To clarify, the data I'm trying to retrieve is counts or how many teeth on the cog went past the sensor and how long that cog was rotating for. initially I was just going to use a proximity sensor to a digital counter and do the math for the teeth of the cog and then take apart a digital stopwatch and solder in a signal to start the stop watch somehow. Then I realized the crux is how do I stop the timer. I'm assuming an Arduino can be coded to stop a timer at the last signal from my the sensor on the cog but that's me assuming. if you guys have any ideas, tips, or forums trying to do something similar send them my way.
I was thinking that setting up something that would see the sensor hasn’t picked up rotation in more than a few seconds or milliseconds and would record the last time of the sensor as it’s stop
Hi,
This article may be of interest, it shows how to time events etc.
https://www.instructables.com/Arduino-Timing-Methods-With-Millis/
So you have two separate problems, both of them with known solutions so it shouldn't be too difficult.
- Count pulses from your sensor and
- Keep track of how long you've been counting
#1 is simple. Configure an arduino input as a digital input and count transitions on that input. This will work up to ludicrous rotation speeds.
#2 requires more information -- are we talking second, hours or days of rotation to be tracked? How slowly does the auger turn? i.e., how will we know for sure that it's stopped rotating.
There's also another problem, which is how do you get this data to your VFD? You didn't say anything about that.
Summary: easy for arduino to do. Your biggest hurdle will be learning how to code.
Can you post a picture of the "cog"? How many teeth? How fast does it turn (RPM)?
NOTE: Hall sensors need magnets to trigger them.
Thank you, I’ll read through this and see what I can find.
I should have described more on what exactly I’ll be doing with this device. Ultimately it will be something I can use on different units so I’m wanting to package it to be transportable. The sensor will be help close to the cog using a magnetic dial indicator base and everything else will be packaged into a box that I’m hoping will have a screen for counts and time. Or may just have to have a hook up for a computer. Not sure yet. This unit will be free of any other operating components of the silo for now. So no info will be collected or sent to the VFD, control panel, or anything else. I’m trying to keep it simple so I can learn how to use these. What ever I come up with will be used only to calibrate the silos then removed for storage. The auger will rotate at a max speed of 180 rpm but will also spin slower to create different motor percentage blot points on a graph to get me the info I need. The time I will be needing is definitely seconds but maybe minutes depending on discharge rate of the auger. I only need enough cement powder out of the delivery auger to weight and then reflect that back to counts and time. Some where between 100lbs-150lbs. I’ll then do this multiple time to give me trials that I can check the deviation on and it will give me averages for counts and time to know #1 that the system is consistent and #2 how long the system need to run for a 29 ton load once I feel confident it’s consistent. I appreciate your response and hopefully that makes more sense what I’m doing, really I was just needing to check that an arduino would do what I need. I’m gonna get on learning code, if you have any resources or tools to us sent them my way!
This cog has 24 teeth, the max rpm will be 180. But I will also need it to spin slower. Maybe 20-40 rpm at its slowest. I thought Hall effect sensors already had a magnet with in and used ferrous materials to trigger them like cog teeth. That’s how I understood but I could be mistaken.
One concept you'll need is (appearing to be) doing more than one thing at a time. The 'blink without delay' example does that - IDE->file/examples/digital. Also search 'non-blocking' code.
One of many examples: Timer counter state change toggle FSM - all at once
Sensing a gear tooth is an application for an inductive prox switch.
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