Is it possible to reuse an existing led circuit

[virii]

Hi,

I found a LED strip that I havn’t used for years and it can be controlled with IR.
I wondering if I can re-use the board and add an ESP8266 D1 Mini to it, theres no need for IR so atleast I can use the 5v pins to powering the ESP.

Board: EC-LED-21A
LED: Unknowed
IC1: t24c02a
IC2: Unmarked

I know it’s not so much information but I think I should give it I try and ask if somebody else have any success with it or if I just should skip that idea and use the ESP with mosfet.Also if someone know what type of LED this is would be greatful.

[virii]

Something went wrong with the picture upload from iPhone and I didn’t manage to delete the post.
Attachment will come when I have access to my computer later today.

[missdrew]

Thats an RGB LED strip, you can use 3 MOSFETs to drive the 3 colours. You need to 'sink' the current to light the LEDs.

[david_2018]

A google search shows the t24c02a to be a 256 byte EEPROM.
The other chip would presumably be the controller, too bad it is not marked.

The board already has three transistors of some type for driving the LED strip, can you read the numbers on those? I cannot quite make it out in the picture.

If you are good at soldering small parts, remove the two ICs and wire the D1 Mini into the pre-existing transistors. Resistors may be needed, hard to tell without knowing what type transistor is being used.

WIth that type of LED strip, all you can control is the color and brightness of the entire strip, the LEDs are not individually addressable.

Be careful if you want to supply power from that board to the D1 Mini, it may not actually have 5 volts even though there are markings for 5V.

[virii]

david_2018:
A google search shows the t24c02a to be a 256 byte EEPROM.
The other chip would presumably be the controller, too bad it is not marked.

The board already has three transistors of some type for driving the LED strip, can you read the numbers on those? I cannot quite make it out in the picture.

If you are good at soldering small parts, remove the two ICs and wire the D1 Mini into the pre-existing transistors. Resistors may be needed, hard to tell without knowing what type transistor is being used.

WIth that type of LED strip, all you can control is the color and brightness of the entire strip, the LEDs are not individually addressable.

Be careful if you want to supply power from that board to the D1 Mini, it may not actually have 5 volts even though there are markings for 5V.

Thanks just the answer/help I looking for.

The 3 transistors is marked ”x2” so maby a SOT-23

[Grumpy_Mike]

so maby a SOT-23

An SOT-23 is just the size of the package the transistor is in. It is not the transistor.

See Arduino Code | RGB LED Strips | Adafruit Learning System

[Paul_B]

david_2018:
Resistors may be needed, hard to tell without knowing what type transistor is being used.

You mean base resistors for BJTs? Not needed for FETs. The strip already contains the current controlling resistors for each three series LEDs.

[virii]

I have now manage to connect the strip with ESP and it work to control it (ESP Home on Home Assistant)
But it only work when powering the ESP thru USB.

I use a multimeter on the 5V pin and G (6) and it´s 4.83V on the strip controller.
As fast as I connect the ESP 5V->5V and G->G it drops to around 1.4V and the ESP don't start.

Without ESP it's:

1. 6.79V
2. 6.79V
3. 6,79V
4. 0.69V
5. 4.83V 6 4.83V
   With ESP 1. goes up to ¨~12V and 6. drops to ~1.4V

Any idea?

[virii]

To answer my on question.

It look like it use zener diode for converting 12v to 5v

It works good for circuit up to 70mA (was used for IR) and D1 mini use ~100mA at startup.

Will use a LM7805 instead

[Paul_B]

virii:
Will use a LM7805 instead

With capacitors.