Help with indicator light - Page 1
Forum section: electronics / beginners

author: edb1984
author_rank: Contributor
timestamp: March 25, 2016, 10:24:44 am
content: Hi there!looking for a little help please - i have a greenhouse with a hydroponics system called dutch buckets - these run from a big tank of water and cycle the water throughout the greenhouse and it comes back to the tank via pipes etc.(For anyone interested here is a video of my system)Its an awesome system, as you theoretically dont need to remember to water the plants all that often - you just top up the tank with water and nutrients- the downfall is that if the tank runs low or you spring a leek in the pipes - the plants die fast as they are not in soil, they are grown in a mixture of clay pebbles.so i have a little electrical system to keep it topped up if it happened to spring a leek, or the water runs low.i have a float switch, a delay circuit and a pump thats connected to a rain water collection system and all powered by a 12V battery thats kept topped up with Solar power.If the float switch is activated then the delay timer will turn the pump on for 60 seconds then switch off.here is my question - if it were to top the tank up i would need to replace the nutrients in the water so i need to have a indication it had topped it up.what would i do to make a light / or buzzer turn on if it had been activated? so that when i went into the greenhouse a day or two later i would know there had been a problem?Thanks in advance for your help!Kind Regards

author: MK14
author_rank: Super Contributor
timestamp: March 25, 2016, 10:41:19 am
content: You could put a (lithium battery powered) electronic LCD counter module. Probably purchasable reasonably cheaply on ebay. Press its reset button, if it is non-zero.Connect it to count each pump activation.Check it is ZERO on each visit.Example: (may be missing reset ?)http://www.rapidonline.com/electrical-power/trumeter-7016-6-digit-lcd-counter-assembly-dimensions-29-4-x-22mm-51-8728

author: Seekonk
author_rank: Super Contributor
timestamp: March 25, 2016, 12:49:45 pm
content: Too bad you are not close by, sounds like a great project for a small micro. It could monitor everything, do automatic fill, run backup pump in a failure and have a limp mode in the event of any sensor failure.

author: MK14
author_rank: Super Contributor
timestamp: March 25, 2016, 12:56:01 pm
content: Another idea (RE: my original post).You could use a latching relay.The pump "activates" the latching relay.When you next visit, the latching relay will still be on, and it could be wired to a flashing LED (low power), or whatever you want (that doesn't run the battery down too quick).You would need to give it a reset switch.Example of a latching relay (£1.60 + vat. UK).http://uk.farnell.com/omron-electronic-components/g6su-2-dc3/relay-signal-dpdt-30vdc-2a/dp/1448191

author: rdl
author_rank: Super Contributor
timestamp: March 25, 2016, 01:13:47 pm
content: It would be good to know how many pumping events would need to be counted.A CD4026 with debounced input connected to a 7 segment LED would be good for up to 9 events. It should be able to be built for under $5 on some perf board. The LED display could be made "push to read" in order to conserve battery power.Example:http://www.edutek.ltd.uk/CBlox_Pages/Digit_Counter_single.html

author: Seekonk
author_rank: Super Contributor
timestamp: March 25, 2016, 01:40:44 pm
content: Sometimes we see the hardware instead of the application. I have an entire house run on a UNO (it was 5 years ago). Several solar array converters, refrigerator, two water heaters, some other stuff and a pump. Entire notification is two LED. A NANO board is only $2.50 shipped and you get a LED on board. If you can think of a alarm or protect method, it can be implemented. There is normal and not normal.