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555 bypass?

RichL

New Member
Hello, I'm new to this forum. I have a mini strobe light device that I purchased from Temu recently. It required the purchase of 4 per order. I had expected these to be an on/off device. It seems that only one of those lights works that way & the three others work off a vibration switch, so they shut off after about 8 seconds until you shake the light slightly - not what I want.

I am not 100% sure but I believe the ones wired to the vibration switch use a 555 timer chip (the chip is not labeled) I am looking for a way to convert them to an on/off like the other one. I tried to jump the vib switch but that doesn't work. Is there a way to jump out the 555 so that I can keep the lights from turning off and work of the switch as an on/off device?
strobe_01.jpg
strobe_02.jpg
 
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Not sure its a 555 timer chip as it is nominally in an 8 pin package.

Regards, Dana.
 
I would expect the chip to be a micro-controller, rather than a 555 - it's quite rare for 555's to be used in commercial equipment, it's mostly a hobbiest device. The function of the device will be in the controllers code, so it's probably not possible to alter the way it works.
 
Yes you are correct. I should have checked the pins first against a normal 555 IC and would have determined they do not seem to match and actually VCC & ground are connected opposite of normal 555 config. This is a controller IC or eeprom, possibly ATtiny202/402. My only option is to pull it and see if I can get a copy of the code, if not protected. More work than it's worth really.
 
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Yes you are correct. I should have checked the pins first against a normal 555 IC and would have determined they do not seem to match and actually VCC & ground are connected opposite of normal 555 config. This is a controller IC or eeprom, possibly ATtiny202/402. My only option is to pull it and see if I can get a copy of the code, if not protected. More work than it's worth really.

There's also a clue that the required support components for a 555 aren't there, of which a fair number are required.

It 'could' be an ATtiny, but just as easily it could be an 8 pin PIC, but more likely it's some cheap Chinese processor. But whatever it is, it's almost certainly going to be code protected - but without knowing (rather than guessing) what processor it is, you're not going to know if you're trying to read the wrong device. or if it's protected.

If the pin connections make sense for a Tiny, you could always remove whatever it might be, and write your code for a Tiny and fit that in it's place. Or just make your own strobe from scratch :D - as is obvious from the pictures, there's not much to it.
 
Thank you for the replies. I was hoping for a cheap & simple remedy to a simple situation, which is why I ordered these. I only needed 1 but they required a minimum purchase of 4. At least 1 does what I need it to do. I'm considering possibly reverse engineering the good one to see if a simple mod can be made to the other 3 lights otherwise it's far more work than I have time for right now, will toss them into the 'bored with free time' bin - thank you for the feedback.
 
It is possible to bypass the microphone sensor, which may be just a piezo ceramic cap with some ball bearings inside that create voltage when shaken. It just needs a low frequency Astable or Relaxation oscillator using CMOS Schmitt inverter &RC and a drive transistor, and current limiter R.

I love how they sand off the part numbers but you can see them with an angular light to see the depressions but not a normal or orthogonal view.



1685193727363.png



The leds are integrated smart LEDs with 8 pins and sensor inputs.
1685194922376.png


The relay is tiny
1685194944381.png


Pretty cheap for $2.48 CA, maybe mount it on the fender which may have lots of vibration or make it vibrate in the wind.

363097a1f72e9cc6206232b2e68eca84.jpg


There must be a way to create a continuous trigger, but not enough details to decipher. We. need signals or a reverse eng. schematic.

For those who have tried TEMU instead of EBAY or Amazon , will appreciate the service. I am impressed.


I suggest you shell out $14 and get a real strobe LED light

 
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