EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: bbjunkie on October 06, 2013, 06:21:58 pm
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Hi!
I'm currently thinking of building a "Bilge Counter" for my boat. Basically a simple (to those that know how) circuit that counts how many times the bilge pump comes on in my boat when im away from the marina.
While I have basic electronics knowledge, I do not have the knowledge to design such a circuit. I have tried google, and other forums but have been unable to locate a circuit that will do what I want.
Basically, I need the following:
2 or preferably 3 digit counter that will increment by 1 every time it receives a voltage from the bilge pump circuit which could be as low as 10v and high as 14.5v counter must not increase again until the voltage has gone back to zero for at least 5 seconds
7 segment display or 16x2 LCD display
If LCD Display then a timer to allow illumination of said display for a preset number of seconds.
Button to allow counter to be reset
extremely low current draw (hence thinking of LCD over 7 segment) thoughts?
Either built from scratch, or a shield for Arduino, however my coding skills only go as far as basic PHP!
Hints & Tips would be very much appreciated!
Cheers for now, and keep up the great work Dave - been a viewer since episode 40 something!
Pete
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Simple...easy...done...
Power an Arduino directly from that 10-14.5v from the pump circuit.
Arduino powers on, waits a few seconds just in case it's a 'spike', increments a counter by one, saves that number in EEPROM, spit that number out the serial lines say once per second.
Bilge pump shuts off, Arduino shuts off (and that's why it waits a couple seconds before incrementing that counter in case there's a 'spike' when the pump shuts off).
Hook up a PC to read the number...but you don't want to do that.
So, hook up a simple serial backpack or 7 segment LED, whatever you want, literally thousands of sketches already out there for doing this. When it's got power, it displays the number. But, it'll be one count too high when you get to reading it because you have to power it on to see it, so subtract one from that number. Have another push button set up to reset that number to zero or short a couple pins together on the Arduino itself.
Whatever works. Not that difficult.
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As Skimask said, or....
You could look into a 7-segment solution also since you already considering a button for "lighting" the display.
I.e. if you use 74HC160 and 74HC4511 (1 for each digit you need) you can use the BLANKING_INPUT pin on the 74HC4511 to control if the display should be lit when a button is pressed or the engine is running. The power consumption will be minimal with the displays off.
It's also possible to disable counting in the 74HC160 when the engine is running (counting the waves) if that's needed.
You can filter the counter input with a RC network to smoothen the counting.
Remember that these inputs needs to be limited to Vcc, typical 5V, which is what you should supply the 74HC's with.
The benefit of using a microcontroller is that you can add-on other things later if you want.
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Just use something like this unit. Only costs £9-15.
http://www.ebay.co.uk/itm/JDM11-6H-6-Digits-Display-Electronic-Counter-Relay-Control-DC-24V-/190837314719?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2c6eca549f (http://www.ebay.co.uk/itm/JDM11-6H-6-Digits-Display-Electronic-Counter-Relay-Control-DC-24V-/190837314719?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2c6eca549f)
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Just use something like this unit. Only costs £9-15.
24v not 12, continuous LED display - too much power. No 5 second de-bounce.
Yeah something 'like' that would do, if you can find something different enough from that in all the right ways. Cheap chinese crap from ebay hardly ever has sufficient information to know what it really does although searching the web might turn up more if you are lucky.
If the OP wants to know how much his boat is leaking (or filling up with rainwater or whatever) then I would have thought measuring how long the bilge runs for would be as if not more useful than how often it ran. There are a lot of cheap hour meters, mechanical or with battery powered LCD display. Most only have 0.1 hour resolution.
This one is 10-30v, mechanical with about minute resolution. Just wiring it across the pump might do the job.
http://www.ebay.co.uk/itm/Grasslin-Hour-Meter-/281178497178 (http://www.ebay.co.uk/itm/Grasslin-Hour-Meter-/281178497178)
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Get something similar to this
http://www.ebay.co.uk/itm/Electronic-Digital-5-Digit-Ring-Tally-LCD-Counter-W-R1BO-/130869969452?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item1e7875422c (http://www.ebay.co.uk/itm/Electronic-Digital-5-Digit-Ring-Tally-LCD-Counter-W-R1BO-/130869969452?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item1e7875422c)
and connect the coil of a read relay or relay to the motor and the relay contacts across the button.
:-+
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Not quite what you ask for but I am happy with this http://www.maxmon.co.uk (http://www.maxmon.co.uk) (tracks humidity in the boat, loss of power, etc.) Made in the UK too.
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Thanks guys for some real good thinking outside the box ideas.
I've got my hands on an Arduino Uno and written a basic script that will read value from eeprom on power up, flash a LED that number of times, then increment the count and write the new value.
It is my intention to add an eeprom reset button before fitting it in the boat.
Should do the job, and I may even add some other cool features like voltage monitoring and a GSM shield to SMS me if anything goes wrong.
Alternatively I will keep it simple and put it on a basic ATTiny45 - not decided yet!
Thanks again for the suggestions
Pete
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buy this and a pencil and paper
connect and have fun
http://www.surpluscenter.com/12-VDC-6-DIGIT-COUNTER-NOT-RESETTABLE/edp_no=26999/shop.axd/ProductDetails (http://www.surpluscenter.com/12-VDC-6-DIGIT-COUNTER-NOT-RESETTABLE/edp_no=26999/shop.axd/ProductDetails)
everything else can go wrong
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why does it seem that any problem now a days is always fixed by "throw a microcontroller in there"??
a very simple solution can be had for this wih a simple counter/timer circuit with a signal from the pump creating a rising edge for a clock signal to advance the counter by one.
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You could even use a mechanical quartz wall clock with a second hand.
Remove the quartz circuit and drive the coil with a simple transistor monostable.
Set the second hand to 12, the other hands to 12 and there you have your counts in real time :-DD
So 5 minutes and 10 seconds past 12 would be 310 starts :-+
:)
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a quick 2 seconds search gives one example:
http://4.bp.blogspot.com/-RWE57ZBsbic/T9EyfDDtySI/AAAAAAAAACU/cUuLnzFLM9c/s1600/two-digit-counter+schematic.jpg (http://4.bp.blogspot.com/-RWE57ZBsbic/T9EyfDDtySI/AAAAAAAAACU/cUuLnzFLM9c/s1600/two-digit-counter+schematic.jpg)
a 74hc926 offers a quick 1 chip solution with a 4 digit display.