Introduction and Assistance - Page 1
Forum section: electronics / beginners

author: Navyguy
author_rank: Newbie
timestamp: February 03, 2025, 02:52:11 pm
content: Good DayMy name is John and I am looking for some assistance on an extremely simple project, but I don’t have the expertise in (so it might as well be brain surgery to me LOL!). I am a Master Electrician and have some experience in electronics, but it is more of a troubleshooting level (changing blown resistors, transistors, installing MOV, etc.) and I have no experience at the design side of things.I am looking to create some flashing LED circuits that will fit into a very small foot print for a volunteer 3D project I am working on. They would have to be powered by a small flat cell battery and have a tiny on / off control.I have looked at a 555 timer with a breadboard and have access to numerous components, so I am also thinking that they may be too big for my application. I am thinking I might have to flash some sort of eprom to literally fit this into a thumbnail sized footprint with the battery and on / off being accessible.Hopefully this is the right place for assistance.As a sample of what I am looking for:White LED = 1 "Quick Flash" (approximately .25 seconds), "off" (approximately .25 seconds),1 Long Flash (approximately .5 seconds and then off and repeat (each cycle is 6 seconds).I have attached a pictorial of what I am trying to explain also.CheersJohn

author: PGPG
author_rank: Frequent Contributor
timestamp: February 03, 2025, 07:15:47 pm
content: Quote from: Navyguy on February 03, 2025, 02:52:11 pmNowadays in many cases most flexible solutions you get by using microcontrollers.When in Mouser I restricted microcontroller list to those having 2,3 or 4 I/O lines I got list of 127 microcontrollers in SOT23-6, USON8, DFN8, UDFN8 and some bigger 8 pin packages.Many microcontrollers can run with their internal RS oscillator not needing any external frequency source.Quote from: Navyguy on February 03, 2025, 02:52:11 pmFor such times with NE555 you will probably be needing relatively big capacitors while in microcontroller you will just use its timer to count needed times.

author: Navyguy
author_rank: Newbie
timestamp: February 03, 2025, 08:05:18 pm
content: Thanks for the reply @pgpg.I am literally looking for a "thumbnail" sized circuit board that would basically fit into the base of a water bottle (2.5") and about 1" in height. This is why I am thinking some sort of ROM that can be flashed as I am evening thinking that the 555 timer chip may be too large to fit into the base.I will search the items you suggested and take a look. Perhaps one of them will be small enough so I can attach that to a circuit board along with a 5v flat battery and a on / off button switch.Thoughts?CheersJohn

author: pcprogrammer
author_rank: Super Contributor
timestamp: February 03, 2025, 08:30:46 pm
content: You can use an Attiny85 module like this:https://www.aliexpress.com/item/1005006291031546.html, or the MCU in its bare form.This is a microcontroller that has everything in it that you need. You can program it with the use of the Arduino IDE and an USBASP:https://www.aliexpress.com/item/1005006827605143.htmlJust programming a ROM as you suggest won't work, because then you would need a clock and an address generator and what ever to step though the blink pattern in your ROM.To play with something first get yourself an Arduino Nano:https://www.aliexpress.com/item/1005006387336449.htmlDownload the Arduino IDE (https://www.arduino.cc/en/software), and look on the net for some tutorials on how to blink a led. There are plenty examples to be found online.The links to Aliexpress are random picks and you might be able to find better deals or more reliable sources. The are to show you what you can be looking for

author: Navyguy
author_rank: Newbie
timestamp: February 07, 2025, 04:53:11 pm
content: This seems like a fantastic idea. It appears from the photos at least it will be small enough to fit where I need / want it to go.I have never used any of this stuff before, so I might be asking for more assistance.Thanks to everyone for the replies. If it actually works, I will post an update.CheersJohn

author: PGPG
author_rank: Frequent Contributor
timestamp: February 07, 2025, 05:19:27 pm
content: Quote from: Navyguy on February 03, 2025, 08:05:18 pmIn 90s I was using NE555 in DIP8 case (the biggest one NE555 is manufactured) as my car immobiliser. Generator based on it was assembled in big Jack plug (detector mounted in transistor ignition circuit). In big Jack there is about 1cm of space.Quote from: Navyguy on February 03, 2025, 08:05:18 pmIC cases I have mentioned (SOT23-6) are about 3mm x 3mm size.