Hi there. i'm brand new here, and im sorry to say my fist post is asking for your help.

Im new to electronics (im only 16 ) so please excuse my stupidity.

Im trying to build a device with the following specs and was looking for some advice really:

counter to count between +40/-40 and have a chip that outputs to a vibrator when the counter is > a specified number. I need two seperate inputs for +1 and -1 aswell as a third button to reset the counter to 0. I dont necessarily need to display the count value, but i would be cool if i could.

Or if it would be easier, have the device reset to -12 (ish) and then have it vibrate when the counter reaches 0.

So far ive got word that im looking @ either

• * 74LS688 : 8-bit comparator with appropriate <, = or > outputs
  * 74LS192 : presettable up/down counter

but im really unsure how to implement either of these chips into a working peice of electronix. A little digging around on the internet has led me to believe i will need to use a PIC to do the when counter > x part.

So im really asking, am i heading on the right tracks here? and do you have any resources with examples of projects of this nature? could anyone help me build something like this step-by-step?

i know that you time is valuable but i would be eternally grateful if you could help me out!

thanks

 

hi,
If its a decimal count to +40 then a 74LS192 up/dwn 'decade' counter would be my suggestion, especially if you want to display the counter in the future.

When you say, +/-40 counters, do you mean a count upto a maximum of 40 and the ability to down count this counter to zero.?
Or
are you saying two separate counters, one counting up and the othe counting down.??? which dosn't sound right to me.

What range of specified 'vibrate' now values do you want to cover.?

You could do this project with logic ic's [74lS192] or a small PIC.

If you go the PIC route, you will have to write the program and also have the equipment to program the PIC..

What do you think.?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

i want it to be an integer count, so 1,2,3,4 etc.

what i mean is counter that can go from -40 through 0 to +40

so if it was at zero and i pressed the -1 button it would count down 1 to -1 and then if i pressed it again it would go to -2, then pressing the +1 button would take it back to -1.

i just want it to vibrate when the number is bigger than 12.

thanks for he;lping me clear that up a bit

 

hi,
Does this help.?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

it helps a lot, thankyou!

wondering how i should wire the 4 x LS192 ?

also would i need a specific logic gate for this or are they programmble chips?

thanks alot.

 

hi,
Look at this initial drawing.

It uses two 74LS192 decade counters.
Pushing the LOAD switch, preloads the counters with 40 decimal.
The +1 and -1 increment switches count up from 40 or down from 40.

The extra logic on the outputs of the LS192 would have to detect when,
count is 28 or less OR count is 52 or greater.

On detecting these limits a latch would be set and the 'vibs' activated.

Is this what you are looking for.?

Whats the purpose of this project..?

__________________
Eric
"Good enough is Perfect"

PIC tutorials:
Gramo's: www.digital-diy.net/
Bill's: www.blueroomelectronics.com/

 

this is fantastic thankyou very much for all this help.

Its going to be for a board game thing that one of my mates is making in his graphics GCSE.

I said i would try and help him with it because im really interested in getting good at electronics.