I Want To Buy Some Design Help

[jeffnick]

> I'm a boater. When on the water, channels are designated by Aids to Navigation (markers). Colors and shapes of these markers are significant. For example, when returning from the ocean one would leave the red markers to the right in order to stay in the deep channel. I made a simple bicolor LED circuit for the boat that helps me remember which color goes on which side.



Now I have a crewmember who is color blind so I need to introduce shapes into the picture. I found a bicolor LED matrix that I would like to use:
http://www.mpja.com/prodinfo.asp?number=16784+OP
but I have absolutely no idea how to go about it.

I'd like to have an on-off-on switch that would be off in the middle and have the matrix display one or the other patterns depending on the position when on.


I'd like to run this on AA batteries.

OK, that's the goal, but because I'm forgetful and wouldn't remember to turn the thing off, I'd need new batteries each time I used it. Would it be possible to have a circuit that would turn the unit off after 60 minutes - unless the switch was returned to off, then back on in either direction. In other words a 60-minute timer that would be reset any time the unit was switched off and back on. And one more thing…to keep from looking at the unit and seeing it was off; a reminder that the timer was running out would be nice – like having the display flash on and off for the last 15 minutes?

Is this possible? What would the design cost?

[violin]

>

> I'm a boater. When on the water, channels are designated by Aids to Navigation (markers). Colors and shapes of these markers are significant. For example, when returning from the ocean one would leave the red markers to the right in order to stay in the deep channel. I made a simple bicolor LED circuit for the boat that helps me remember which color goes on which side.

Now I have a crewmember who is color blind so I need to introduce shapes into the picture. I found a bicolor LED matrix that I would like to use:
http://www.mpja.com/prodinfo.asp?number=16784+OP
but I have absolutely no idea how to go about it.

I'd like to have an on-off-on switch that would be off in the middle and have the matrix display one or the other patterns depending on the position when on.

I'd like to run this on AA batteries.

OK, that's the goal, but because I'm forgetful and wouldn't remember to turn the thing off, I'd need new batteries each time I used it. Would it be possible to have a circuit that would turn the unit off after 60 minutes - unless the switch was returned to off, then back on in either direction. In other words a 60-minute timer that would be reset any time the unit was switched off and back on. And one more thing…to keep from looking at the unit and seeing it was off; a reminder that the timer was running out would be nice – like having the display flash on and off for the last 15 minutes?

Is this possible? What would the design cost?

Hi. What you are requesting seems to be very achievable to me. However, it does mean the use of a microcontroller of a type. This will control the power to the matrix LED’s direction maker peripheral, via say an opto-coupler. It will also control the power to the 15min warning flash LED/s peripheral, again via an opto-coupler. My suggestion would be to use a 555 timer chip for this very purpose of a warning LED/s. Once the microcontroller timer program has reached the 60min designated cut-off time, it will then power-off all its peripherals and it will also power-down, placing itself into sleep-mode, again via the written program so as to achieve this saving on power consumption function. - To power-up the microcontroller can be easily achieved by simply resetting it, powering back on its direction maker peripheral. The position of the direction markers toggle switch will determine the LED markers pattern once powered back on. The LED warning flasher circuitry will not be powered-on until the timer program has reached the later stage of itself. The timer itself can be ether internally written or externally written, - for example using something like the DS1302/1307 RTC chip, the choice is yours. If you do opt for an external RTC chip as another peripheral to you intended application, - then you will also need to write into the program to power-off once its designated time has been reached. To power-off (against powering-down) the microcontroller at any time will require a manually controlled switch.

All this said, I am wondering in why such an important piece of navigational equipment as I understand it; has to have its power supplied by AA batteries as I don’t think its going to be a hand held piece of equipment. Is it?

Its cost: One suitable microcontroller with its discrete circuitry, - although it will need to be programmed with its appropriate code. One 555 timer chip and also to include its discrete circuitry and a (optional) RTC chip and again with its discrete circuitry. Can’t be more than £5 for all these bits, I would say, although pricing is not my speciality.

Regards

[violin]

>

Hi Violin,

Thanks for the encouraging reply. I only know the very basics of electrical circuits and this project is well above my level.

Hi. I felt it better to keep this reply “open” and not as only as Private Message as it can be beneficial to others who visit this forum as well as to your good self as you may get better advice than mine. I hope you don’t mind.

First off, the reason for the "AA" power is that I can/have put together the same display for 12VDC. Forgive the crude explanation but I don't know the terms you guys use.

OK you are running/intended to run everything from a 12vdc line, that’s fine. I guess rechargeable battery/s is not suited for this application so if they do go flat due inadvertently left on, they can always be re-charged.

I use a bi-color LED with 3 leads. I drilled #10 holes in a picec of plastic and mounted 10 LED's. I created 2 circuits by soldering wires to the leads of the LED's; one with the red triangle on the left and one with it on the right. The circuits are fed from a switch. I toasted my first attempt by connecting the LED's directly to the 12VDC. To get to the right voltage I put a very big resistor in the +12 and kept making it smaller until I got the LED's to light up without getting anything too hot. So now you're familiar with my trial and error skill level.

For a 12volt line I myself use just use three choices of resister values for a single LED circuit (or a 3 leg bi-colour -2 anodes 1 cathode), 1k for power consumption saving, 680R for power consumption saving and for LED brightness - and 470R for brightness only and not for a power consumption saving factor.

I would like to have one that is portable for temporary use on other boats and have made the single LED versions for that purpose (for those I use a 2 wire bi-color and just switch the direction of the current). I'd like to have the "AA" version more just because I think it's a nifty idea than for any practical purpose.

I am not sure in why you are using bi-colour LED’s,- as from your posted images and also from your description above I was under the impression that direction colour patterns were each separated from one and other (am I wrong on this) and bi-colour LED’s wouldn’t have any practical advantages in this particular application as you will not be making full usage of them, leaving one of the anode (3-legs) legs unconnected or not direction switching (2-legs) the current.

I've purchased kits to learn about these circuits but this stuff is beyond my ability to comprehend.

Which kits? Maybe I can assist you in further learning from them.

Anyway, would you, or someone you know, be interested in building a couple of these portable units for me? I'd be happy to supply the parts (if I'm instructed what to send) and pay up front for time. I could PayPal the money?

TX
jn

Myself I don’t know anyone of my level of experience (other than forum users) who would be able to take this project of this nature and myself I am so busy with my own projects so as to be able to have the time to take this on. It is also for this reason I felt it better to post your response to my reply within the forum.

Being retired, my time is divided between wife/dog/boating/tinkering. To give you an idea of one of my projects, look here:

Thanks for the link. I will take a look at it when I have a bit more time on my hands. Regards

[jeffnick]

> Thanks for the reply and I can understand that you're busy - I used to be in that position myself.

Anyone else out there who might be able to put this circuit together for me?

[jeffnick]

> Which kits? Maybe I can assist you in further learning from them.

I did an Cleveland Institute of Electronics course by mail back in the 70's. Couldn't get past the tuned tanks.
About a year ago I bought an Electronics Learning Lab from Radio Shack and could wire the 'beginners' circuits but never could understand how things worked, that's why I'm looking for help.

[violin]

> http://www.esr.co.uk/velleman/products/ ... inikit.htm

Maybe this easy to (MK128 Kitchen Timer Mini kit) build kit could be adpated to suit. it's just an idea.

[jeffnick]

> We have a motion detector LED light in the bathroom that runs on "AA" batteries. It had 6 white LED's. I replaced those 6 with 10 3 lead LED's and a switch wired so 7 of the LED's are lit at one time. The unit still functions with the motion detector circuit, but also has an 'on' selection. The picture is deceiving - these LED's are not really visible in the sunlight.



If I can figure out how to get the right LED's to light with the LED matrix in the first post, I'll use that instead of the individual LED's. I'd still like one that blinks before it goes out tho'.

And thanks for the link. I might have fun with something there.

[violin]

> Ah, from your photos of your infra red detector it is now clear to me in how you are utilizing the bipolar LED’s, for illumination direction pattern display.

If I can figure out how to get the right LED's to light with the LED matrix in the first post, I'll use that instead of the individual LED's. I'd still like one that blinks before it goes out tho'.

That’s seems simple enough since the matrix display fits your requirements. Just cut/jump out the individual LED’s (legs) that you don’t wish to be illuminated within your configuration.

You can always switch in and out (3-mode switching - flash, static on or static off) a 555 timer chip (astable mode) as stated previously for the purpose of blinking a particular LED at any particular time.

[jeffnick]

> I think I have the matrix thing figured out so I can wire the 2 circuits; bought a project board/box. I've also been studying up on the 555...still have a long way to go, but I'll keep at it. Some of the stuff in my Radio Shack kit make a little more sense now. If I take this project one step at a time, I might be able to make it work?

A lot of things now are powered by a USB cable. I've got a couple things that recharge batteries via the USB connection...my cell phone and a GPS module, both use 3.7V LI-ION batteries. I have many adapters for converting 12VDC into a power/charging source for the USB devices. I'm wondering about using one of these 3.7V batteries to power my display and using 12VDC from the cigarette lighter socket to charge the battery (or power the device).

What do you think about the idea of a rechargable battery via USB power? What kind of resistors would I need in that circuit for 7 of the LED's?
LED matrix specs

[violin]

> If you feel that the 7 LED’s current consumption won’t drain the battery too quickly, I don’t see any reason in not using 3.7v lithium-ion batteries for this particular project. Although you will need to keep in mind the 555-timer chips working voltage parameters – if considering using it for flashing/blinking a LED. I have always used 12volts supply for this particular chip. It will drop down further, but I will need to check on its specs to see how far and also if there is a low voltage one available.

I really have no opinion this or that way on battery charging via a USB port. Personally never had to call for this particular option in relation to battery charging with any of my applications.

The LED’s resister values will depend on the supply voltage rating taking in the consideration of current consumption against its brightness. I can give ideas but will need to be sure of the supply voltage rating first.