FearOfTheDark's Modified Light for the 10th Annual BLF/OL Contest

I am so happy that another BLF competition has started. :sunglasses:
I have a project that I have been putting off for a long time. So I hope the competition will give me the necessary motivation to start (and complete) it soon.

One of my favorite headlamps (Nitecore HC90) was destroyed by water ingress which caused corrosion on the circuit. I tried to fix it without success. I also contacted the manufacturer and asked to buy spare parts but they no longer have spare parts for this discontinued model.

Since I love this flashlight and don’t want to throw it away, I decided to build a new circuit that would support the three RGB LEDs as well as the main white LED.
I don’t believe that I will be able to restore the magnetic slide switch, but I want to maintain the stepless ramping for the white LED.

For those who are not familiar with the model, here is a brief description from the Nitecore website:

The corroded board and some of my tries to fix it :

Final look and video from the stairs

View post on imgur.com

Looks like a good project FearOfTheDark. :+1:

Maybe you could implement linear dimming work with a slide potentiometer.

This is a good idea but it will not be waterproof and water caused this whole mess in the first place :slight_smile:

I have completed the board with the positive pole and a microswitch.

Instead of the USB charging socket, I inserted a switch boot. Under the boot, I placed a board with an electronic switch on one side and a spring on the other. I had to sand the board so that it would sit exactly in place like the original board.

The work on the circuit board: I sawed and sand the Protoboard to fit exactly like the original one


Continuing the work on the board: adding a copper contact for the negative pole (lamp body)

Soldering the 8 current regulators to the Protoboard:

These 8 thin wires are part of the next step I started working on but haven’t finished yet and will share next time…

Wow. I wasn’t expecting this!

I believe this will be good :+1:

Thanks guys.
Hope it will be good.

“Dead bug” soldering the MCU (The wires may be familiar to you):

:slight_smile: :+1:

Nice work so far, can’t wait to see the finished product. What firmware are you going to use? Anduril for the stepless ramping?

Thanks, I wrote my own FW.
Actually that’s why I only started making progress with the HW in the last few days, I was busy writing the code.
I did not find any existing FW for controlling four LEDs (RGB+W)

I haven’t updated on my progress in the last few days because after soldering almost the whole circuit I couldn’t get it to work :frowning:
I had to desolder all components and wires and repeat everything, step by step, until I realized that the problem is probably with the current regulators.
I couldn’t figure out which of the components is defective so I will replace them all.

Very frustrating. I’ve run into that and now am certain to test the operation many times as assembly progresses. Keep up the good work. :slight_smile:

So it turns out I was just unlucky twice and two defective regulators managed to get into my component pool. I have to stop ordering components from AliExpress :person_facepalming:

After I replaced all the regulators I encountered the same problem again - changing the PWM did not affect the LED and it illuminates constantly in low brightness , even with a cycle time of 0.

I turned to the BLF experts for help, but the solutions they offered me did not solve the problem:
I added a capacitor to filter the noise on the ATtiny’s voltage and even lowered the ATtiny’s frequency.
Unfortunately, lowering the frequency to 128KHz locked the ATtiny to burn and before I realized it, I changed to my second ATtiny and destroyed it too.

I was very desperate because I had no more ATtinys left to replace and I was already considering abandoning the project.

Finally, after some online research, I found a tip to change the frequency of the ISP’s clock and I was able to burn to the ATtiny again but I still haven’t solved the problem with the regulators.

I decided to desolder all the regulators from the circuit again and check them one by one until I found the faulty component and threw it away.

After all this struggle I soldered the working regulators back to the circuit for the third time and now it finally works properly.

Frankenheadlamp! Love it. Can’t wait to see how this turns out.