LED light design

[ankanphukan]

Hello,
I am working on designing a led strip which must operate in the following manner:
Blink—> Blink—>Blink—>Fade ON.

Is there any possible way to achieve this without using any microcontroller IC?

Please help me out !!

Thank you in advance.

 

[Chalo]

Hello,
I am working on designing a led strip which must operate in the following manner:
Blink—> Blink—>Blink—>Fade ON.

Is there any possible way to achieve this without using any microcontroller IC?

No. Maybe you can find one with its own microcontroller that does what you want, but there will be a microcontroller of some kind.

 

[ankanphukan]

No. Maybe you can find one with its own microcontroller that does what you want, but there will be a microcontroller of some kind.

Thank you so much for your input. I will definitely have a look into it.

 

[amberwolf]

There are already devices out there to do this sort of thing:

brake light flasher unit - Google Search

you'd have to check which ones actually do the complete operation you want, but I've seen some that do.

If you really want to do it yourself:

The only easy way I can think of is using an MCU of some type, PWMing an MCU output to the LED driver chip or transistor, etc. You can probably even find open-source projects like on arduino.cc / github / etc that have code for various parts of it you can borrow.

You could do it with a complicated discrete-logic version, but it would be more power hungry and much larger and harder to design and troubleshoot--and if you decided later to have it work differently, you'd have to redesign it instead of changing a few lines of code.

A smaller and slightly less complicated version would use an ASIC but that's not really any different from programming an MCU...and you'd have to learn how ASICs work, have their dev environment and setup hardware, etc. Much easier to use an MCU.

 

[glennb]

Sounds like a homework problem.

Anyway, totally not my thing, but I imagine it’d be a achievable with analog components if you separated the tasks and ran parallel strips with one providing the blinking and the other the fading.

 

[ankanphukan]

There are already devices out there to do this sort of thing:

brake light flasher unit - Google Search

you'd have to check which ones actually do the complete operation you want, but I've seen some that do.

If you really want to do it yourself:

The only easy way I can think of is using an MCU of some type, PWMing an MCU output to the LED driver chip or transistor, etc. You can probably even find open-source projects like on arduino.cc / github / etc that have code for various parts of it you can borrow.

You could do it with a complicated discrete-logic version, but it would be more power hungry and much larger and harder to design and troubleshoot--and if you decided later to have it work differently, you'd have to redesign it instead of changing a few lines of code.

A smaller and slightly less complicated version would use an ASIC but that's not really any different from programming an MCU...and you'd have to learn how ASICs work, have their dev environment and setup hardware, etc. Much easier to use an MCU.

Thank you so much. Actually recently I saw a video where a guy had achieved it using an IC, but I could not figure out what was the IC that was being used. The circuit board was pretty small and I could only see a small IC, with almost the same form factor as the 555 timer.

That made me wondering how can I achieve that. I believe we can not achieve it using the 555 timer as the output pin will continuously give high and low signal.

 

[ankanphukan]

Sounds like a homework problem.

Anyway, totally not my thing, but I imagine it’d be a achievable with analog components if you separated the tasks and ran parallel strips with one providing the blinking and the other the fading.

Thank you for your input.

 

[amberwolf]

Thank you so much. Actually recently I saw a video where a guy had achieved it using an IC, but I could not figure out what was the IC that was being used. The circuit board was pretty small and I could only see a small IC, with almost the same form factor as the 555 timer.

That made me wondering how can I achieve that. I believe we can not achieve it using the 555 timer as the output pin will continuously give high and low signal.

You'd need more than just a 555 and associated passive parts. You would probably need at least two to create the three pulses, and then other control logic to stop the pulsing after three, then further logic and analog parts to fade it out. The 558 quad timer chip might work but I don't know that you have all the pins on it you need access to; might take two 556s. Using one for PWM control of a bigger transistor to modulate the LED current would be easiest if not using a dedicated driver chip, but it's still a lot more parts than just the MCU and a PWM-controlled LED driver chip.

Using the latter, you could use the ATTiny (TinyAVR) or Arduino Nano and "dead bug"-wire the driver chip in if it doesn't need a PCB-plane heatsink; I doubt it would cost much more than $10 for all the parts to do it depending on where you order from (almost certainly cost more in shipping)

IIRC the ATTiny comes in a small 8pin DIP like the 555, if not there's surely a 16pin version with more I/O, the small one is less than a dollar for the bare chip, maybe a couple bucks for a tiny USB-dongle-PCB version. The Nano is only the size of the board out of an older USB data storage thumbdrive, and might be easier to write code for (or find code that does what you want), probably costs a buck or two. I have never explored the AT-series directly, but seen plenty of projects that use it including for lighting. IIRC there is an LED battery meter project here somewhere that uses one to flash a single LED to provide battery SoC.

 

[ankanphukan]

You'd need more than just a 555 and associated passive parts. You would probably need at least two to create the three pulses, and then other control logic to stop the pulsing after three, then further logic and analog parts to fade it out. The 558 quad timer chip might work but I don't know that you have all the pins on it you need access to; might take two 556s. Using one for PWM control of a bigger transistor to modulate the LED current would be easiest if not using a dedicated driver chip, but it's still a lot more parts than just the MCU and a PWM-controlled LED driver chip.

Using the latter, you could use the ATTiny (TinyAVR) or Arduino Nano and "dead bug"-wire the driver chip in if it doesn't need a PCB-plane heatsink; I doubt it would cost much more than $10 for all the parts to do it depending on where you order from (almost certainly cost more in shipping)

IIRC the ATTiny comes in a small 8pin DIP like the 555, if not there's surely a 16pin version with more I/O, the small one is less than a dollar for the bare chip, maybe a couple bucks for a tiny USB-dongle-PCB version. The Nano is only the size of the board out of an older USB data storage thumbdrive, and might be easier to write code for (or find code that does what you want), probably costs a buck or two. I have never explored the AT-series directly, but seen plenty of projects that use it including for lighting. IIRC there is an LED battery meter project here somewhere that uses one to flash a single LED to provide battery SoC.

Ohh thats a cool idea. Let me explore a bit more. I will keep you updated. Thank you so much.