Reading a flowmeter with an Arduino or other MCU
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- Posts: 184
- Joined: 16 years ago
Has anyone done any work on reading a flowmeter with an Arduino, PIC, etc? I'm assuming it's some kind or analogue pulse that would need to be read, so would I need to feed the flowmeter into a comparator before the Arduino?
Any help would be appreciated.
Any help would be appreciated.
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- Posts: 184
- Joined: 16 years ago
Whoops; I did a search first and came up with nothing, but straight after I found this
Gicar flowmeter signal
This looks like I could use PulseIn() as described at http://arduino.cc/en/Reference/PulseIn
I would still like to hear from anyone else who has already done this.
Gicar flowmeter signal
This looks like I could use PulseIn() as described at http://arduino.cc/en/Reference/PulseIn
I would still like to hear from anyone else who has already done this.
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- Posts: 15
- Joined: 17 years ago
hello,
I never finished the home made flow meter electronics, and as my machine gets turned on and off every day it would loose the settings anyway, so I wasn't too motivated.
as I understand it you want to connect an off the shelf flow meter to a home-brew controller.
if you want to use this flow-meter you'd have to get the voltages right for a PIC or similar, ie. 5 v or less
as the standard flow meters work on 18v or thereabouts, you might have to put in a reed switch or similar to switch a lower voltage supply. or do something with resistors to lower the voltage.
I do still think that the flow-meter sinks the voltage from the controller, but as I never got to the bottom of this I cannot say for sure.
Hope this helps.
I never finished the home made flow meter electronics, and as my machine gets turned on and off every day it would loose the settings anyway, so I wasn't too motivated.
as I understand it you want to connect an off the shelf flow meter to a home-brew controller.
if you want to use this flow-meter you'd have to get the voltages right for a PIC or similar, ie. 5 v or less
as the standard flow meters work on 18v or thereabouts, you might have to put in a reed switch or similar to switch a lower voltage supply. or do something with resistors to lower the voltage.
I do still think that the flow-meter sinks the voltage from the controller, but as I never got to the bottom of this I cannot say for sure.
Hope this helps.
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- Posts: 184
- Joined: 16 years ago
Well as a first step, I think I'll set up a test bed with a pump and a flowmeter and put a scope on the flowmeter and see what I get.
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- Posts: 304
- Joined: 15 years ago
If you are just trying to get a standard flow meter to work with a Arduino I think I can help. I have attached a circuit that is used by both Digmesa and Gicar. Essentially there is just a hall effect sensor close to the impeller blade inside the meter. The impeller has he magnets on it. Every time a magnet passes the Hall Effect Sensor it closes.
If you place the corret resistor in the circuit (to limit the current to the micro) then you an use any of the rated voltage. Gicar uses the transformer voltage (usually 9 or 12V). If you want to see what it does on a scope I can probably take a little video.
EDIT: whoops here is the lin for the documentation
http://www.digmesa.com/digmesa/upload/p ... F01_GB.pdf
BIll C
If you place the corret resistor in the circuit (to limit the current to the micro) then you an use any of the rated voltage. Gicar uses the transformer voltage (usually 9 or 12V). If you want to see what it does on a scope I can probably take a little video.
EDIT: whoops here is the lin for the documentation
http://www.digmesa.com/digmesa/upload/p ... F01_GB.pdf
BIll C
- dsc
- Posts: 1166
- Joined: 17 years ago
Hi guys,
always thought it acts like a simple switch, but without the need to debounce it, so it should be fairly simple to count the 'ticks'. You can try (compare to a normal input) and hook it up to an interrupt pin, just make sure you don't do much in the interrupt itself, otherwise you might miss some edges.
Regards,
dsc.
always thought it acts like a simple switch, but without the need to debounce it, so it should be fairly simple to count the 'ticks'. You can try (compare to a normal input) and hook it up to an interrupt pin, just make sure you don't do much in the interrupt itself, otherwise you might miss some edges.
Regards,
dsc.
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- Posts: 184
- Joined: 16 years ago
Yeap, that's the way I'm going at the moment. I've just got the interrupt working on a pulse, wo I'll use the circuit BillC provided (thanks Bill) to link it up. Thank goodness the Arduino supports interrupts and hardware timers.
- CRCasey
- Posts: 689
- Joined: 15 years ago
Just a suggestion, but a opto-isolator in there will prevent any strange voltages from crossing the two circuits. And since most isolator chips work open drain you can use a voltage on the downstream side that your micro controller is compatible with.
-Cecil
-Cecil
Black as the devil, hot as hell, pure as an angel, sweet as love-CMdT, LMWDP#244