Continue to Site

Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

7555 pulsating led

Status
Not open for further replies.

MrDEB

Well-Known Member
designing a Statue of Liberty lapel pin for the 4th of July 2023'
have two similar schematics for a pulsating led (white 3mm led) but the capacitors are electrolytic caps that are larger than 3mm in diameter (have only 1/4 inch height restriction. THINKING of maybe using a titanium cap or? need to order parts but the capacitor size?
both of the schematics are basically the same.
 

Attachments

  • Schematic_7555#2_2023-03-11.png
    Schematic_7555#2_2023-03-11.png
    196.9 KB · Views: 274
Can that chip run on a 6V (or some arbitrary) battery voltage without problem?
Does that generate the ramp up and down that the TS wants?
Code can produce ramp, linear or log (eye has log response), or whatever.

Chip timing accuracy 4% or so, no fat cap needed, flash rate consistent.
No initial rate inaccuracy due to sloppy electrolytic cap tolerance.
85027.jpg


Chip can run 2V to 6 V. or use reg.....a zener and a R to reg power. Or TO92 3 term
regulator.

And of course we can put it to sleep easily.....and we have more pins and A/D,
could add low battery signaling for the LED to warn user.....

All is good......


Knight
 
Last edited:
Post a pic of what you have, eg. mBlock....

Board for dev would be UNO or Nano. That can then be used to program the
ATTINY85 as well.


Regards, Dana.
 
Come on guys. You should recognize the futility of everything stated above. (6000 posts will verify this.)







Just use a self-flashing LED. Battery. Power. Done. White self flashing LEDs are 4 cents at Tayda. Yellow are 3 cents, with the advantage of a lower Vf.





 

Attachments

  • Screenshot_20230311_122203_Edge.jpg
    Screenshot_20230311_122203_Edge.jpg
    124.8 KB · Views: 206
Of course this is one consideration for flash rate accuracy :

How often does flashing light trigger seizures?


Generally, flashing lights between the frequencies of five to 30 flashes per second (Hertz) are most likely to trigger seizures. In order to be safe, the consensus recommends that photosensitive individuals should not be exposed to flashes greater than three per second.

Regards, Dana.
 
I downloaded the Mblock but it looks like all graphics.
I downloaded the windows version
Yes it is all graphic block IDE. It gens code as you construct blocks.

Then uses Arduino programmer to program board. You can of course use
its generated code in Arduino and further mod that in C/C++ should you so
choose. But once you do additional mods outside of mBlock you would have
to keep track of mods if you continue to use mBlock in further code development.
"Normally" one would not use that approach, just stay using mBlock.

If you want to program chip, eg. to use in actual proto, the ATTINY family, you can
use the board as an ISP for the chip.


Regards, Dana.
 
most anything can go WRONG.
I want to use the 7555 as the LM3909 are $$$
yes, a pic would be easier but the cost is a factor.
I could just have the LED light up but there goes the WOW! factor
These lapel pins are 30mm x 110mm and 1/2 inch thick. The circuit is sandwiched between 2 -1/8" plexiglass with a 1/4" cavity for the circuitry.
You've already got a PIC programmer, so where does the cost come from? - and as you'd like to use an LM3909 then you're only wanting a flashing LED anyway, no need to mess about with trying to fade it. However, it could easily be done with PWM from a PIC anyway.

From RS Components (now just RS) a PIC16F18313 is £1.53+VAT, it's 8 pin, and vastly more capable than you need.

A few lines of C (using the free XC8 compiler) is all you need to flash an LED - plus the setup code of the chip, which can be created entirely by the MCC.

Something crude like this:

C:
#define ondelay 200
#define offdelay 500

while(1)
{
    RA0_SetHigh();
    __delay_ms(ondelay);
    RA0_SetLow();
    __delay_ms(offdelay);
}

Simply set the ondelay and offdelay defines to the number of ms you want.

One 8 pin PIC, one resistor, one LED - as simple as that.
 
Note mBlock has a rich library of extensions that can be added to its block
library (see below the add button at bottom

1678615662739.png


24 pages of these addons :

1678615749764.png


Note, depending ion extension, in Chrome browser you may have to set Windows security to
allow import of the extension. thats a one time setup.


Also some extensions board specific.

Also keep in mind many GUI IDEs like mBlock all with their own twists,. Like Snap4Arduino,
Tuniot (fastest way to bring up a server or client I know of), Scratch and its variants, Flowcode,
Visuino, Ardublock....NodeRed.....

Also ATTINY, many variants, down to 51 cents, but not sure how many can be used with
mBlock. I generally use a Nano or Uno board, then try programming a much smaller device
than what is on those boards, to see if it will handle the code generated in terms of memory, etc...



Regards, Dana.
 
Last edited:
You keep pushing this block coding but I haven't seen any examples?
Sounds like bloat ware to me, or is it?

Mike.
MIT major proponent, Scratch and it has several spinoffs, use your browser and
google block "programming language", google produced 218,000,000 hits.....

Google also working on it, Blockly.....

The idea behind block programming is to remove the rigid constraints imposed by
C and C++ from user. And address visual learners. Not perfect, neither is C or C++.
Kids in 6'th grade programming robots with it. My grandson has done some simple
stuff with it both in school and with me. His school started him age 7 I think. And
it allows users to look at C/C++ generated, a bridge.......

Post on these various websites and ask how many downloads, not a precise answer
but certainly one more datum of usage.......

You keep pushing this block coding but I haven't seen any examples?

Post # 14 I showed links to 2 applications. Here is one for web work :

Note I keep seeing people pushing PIC, when they could be using an SOC that has
logic level elements, DSP, 20 bit DelSig, SAR, OpAmps, Mixers, routable, custom user generated
onchip components as well, LUTs, Display......but I know folks in my profession, who never
emerged from the vacuum tube era. To be human is to be imperfect. :)


Regards, Dana.
 
Last edited:
after reading all the suggestions as well as post#27 as well as contemplating different ideas I might go with the flickering led as per post#27 but I need to research the LEDs at Tayda (I need 3mm not 5mm LED)
one solution is to put the 5mm LED in series with the 3mm led and now you have a flickering 3mm LED.
 
Post an example.
LINKS TAKE YOU TO EXAMPLES

DO YOU WANT FILES, GO TO RESPECTIVE BLOCK LANGUAGE SITE AND DOWNLOAD THEIR
EXAMPLES, OR TO THEIR USER GROUPS.

OR DUPLICATE THE SCREEN SHOT BLOCK EXAMPLES IN THE LINKS I POSTED FOR YOU AND FORUM TO CLICK ON.
 
Status
Not open for further replies.

New Articles From Microcontroller Tips

Back
Top