LED Sequensing or chasing

[Angus0071]

I have built a control panel to turn on and off pumps, open and close valves and measure water levels in various tanks. I'm using an arduino Mega, relay boards and float switches to do this but now want to add some bling to the panel itself.... The panel is displayed graphically with a diagram of valves, piping and tanks and tank level gauges using red, yellow and green leds. What I want to do is place green leds every 1 inch on each line representing the pipe and when the valve for that pipe is open and water is flowing, I want to show the leds traveling or chasing each other down the pipe on the panel. How can I get this to work? Keep it simple please..... I have multiple pipes with different quantities of leds on each... More than one pipe can be flowing at a time.

Is what I have in mind not worth the effort!!! Should I settle for solid green or solid red........

 

[AnalogKid]

You can pile more code into the Arduino and add an output decoder/driver, or build a relatively simple chaser circuit.

1. Is the LED pattern one direction only?
2. What are the color and power requirements for the LEDs? For example, a typical small green LED needs a minimum of 2.1 V and 10-20 mA for reasonable brightness.
3. Are any of the chaser LEDs on without chasing?
4. How many circuits?
5. How many LEDs per circuit?

A simple chaser is a 555 astable oscillator driving a CD4017 Johnson Counter. Up to 10 LEDs, one direction only, not very bright unless you use high brightness/high efficiency LEDs rather than 10-cent jellybean parts. Next step, add beefier transistors to drive the LEDs. These can come in an array of 7 or 8 to a chip, saving a lot of parts connections.

The second circuit on this page is the basic approach:
http://e-project4u.blogspot.com/p/led-projects.html

Here is another version with up to 16 outputs and greater output current drive:
http://www.elektroniksforkids.com/projects/view/PRO118/LED-Chaser-16LED.php

ak

 

[Angus0071]

I found the 10 led chaser as a very cheap kit on ebay. Is there a possibility of putting 3 leds in parallel with each of the 1-10? Would this burn out the IC? Even if I could put two leds in parallel for each of the 10, I could run a string or one circuit of 20 leds, 1 to 10 and then 1 to 10 again in a string. I would need a chaser board for every circuit in this case....

 

[AnalogKid]

I found the 10 led chaser as a very cheap kit on ebay. Is there a possibility of putting 3 leds in parallel with each of the 1-10? Would this burn out the IC?

Impossible to say without a link to the kit...

Even if I could put two leds in parallel for each of the 10, I could run a string or one circuit of 20 leds, 1 to 10 and then 1 to 10 again in a string. I would need a chaser board for every circuit in this case....

There are several ways to go. If the operating voltage of the kit is 9 V or 12 V, then you can put multiple LEDs in series on each output and adjust the current limiting resistor.

If the goal is to have one chaser circuit driving several lines of LEDs, and enable one or more lines at a time, that is not a big deal modification but it will require some more parts. What is telling the chaser to go or not go? Outputs from the Arduino? Or do you want the chaser to examine an output already doing something else and determine if it should activate?

ak

 

[Audioguru]

I make bright chasers with the high speed Cmos iC the 74HC4017. Its maximum allowed output current is 25mA and it works with a supply from 3V to 6V.

If LEDs are connected in parallel then they must have matched forward voltages or else the one with the lowest voltage will hog all the current and soon burn out and the other ones will be dim or will not light until the lowest voltage one burns out.

 

[Angus0071]

You can pile more code into the Arduino and add an output decoder/driver, or build a relatively simple chaser circuit.

1. Is the LED pattern one direction only?
2. What are the color and power requirements for the LEDs? For example, a typical small green LED needs a minimum of 2.1 V and 10-20 mA for reasonable brightness.
3. Are any of the chaser LEDs on without chasing?
4. How many circuits?
5. How many LEDs per circuit?

A simple chaser is a 555 astable oscillator driving a CD4017 Johnson Counter. Up to 10 LEDs, one direction only, not very bright unless you use high brightness/high efficiency LEDs rather than 10-cent jellybean parts. Next step, add beefier transistors to drive the LEDs. These can come in an array of 7 or 8 to a chip, saving a lot of parts connections.

The second circuit on this page is the basic approach:
http://e-project4u.blogspot.com/p/led-projects.html

Here is another version with up to 16 outputs and greater output current drive:
http://www.elektroniksforkids.com/projects/view/PRO118/LED-Chaser-16LED.php

ak

1) Yes, light pattern is only in one direction
2) Small green led or a small RGB so I can display solid red when off and tracing green when on. I can handle the solid red! lol
3) My plan was to have all green chasing, but maybe I should have every third steady and the others chasing so I can minimize the number of chasing LEDs. Maybe try to get down to ten or under chasing so I can use a cheap sequencer board for each circuit.
4) I have 10 circuits, but 6 of them are 5 leds or less so I can use one sequencer for two circuits.
5) The leds per circuit can vary between circuits and also can be adjusted by spacing and maybe keeping every third steady..... Right now I have it drawn up to have 28 in the longest leg, however I can easily double my spacing and make every 3rd steady to reduce that to 10.

 

[Angus0071]

I make bright chasers with the high speed Cmos iC the 74HC4017. Its maximum allowed output current is 25mA and it works with a supply from 3V to 6V.

If LEDs are connected in parallel then they must have matched forward voltages or else the one with the lowest voltage will hog all the current and soon burn out and the other ones will be dim or will not light until the lowest voltage one burns out.

Would you have a schematic you could share?

 

[Angus0071]

Impossible to say without a link to the kit...


There are several ways to go. If the operating voltage of the kit is 9 V or 12 V, then you can put multiple LEDs in series on each output and adjust the current limiting resistor.

If the goal is to have one chaser circuit driving several lines of LEDs, and enable one or more lines at a time, that is not a big deal modification but it will require some more parts. What is telling the chaser to go or not go? Outputs from the Arduino? Or do you want the chaser to examine an output already doing something else and determine if it should activate?

ak

Outputs from the arduino are driving relays, so that's what I planned on using as the control for the leds as well.

 

[Audioguru]

Would you have a schematic you could share?

The e-project4u.blogspot.com link in post #2 stole my 6V Chaser project using higher voltage coloured LEDs from my project I posted at www.electronics-lab.com . At electronics-lab I also posted a 3V Chaser project using low voltage red LEDs. Two or four AA alkaline battery cells power them continuously for 3 months. The voltage of each cell is 0.7V when the LEDs become too dim but the chasers are still running.
Here is the schematic of my 6V Chaser: