Author Options:

Help about Pogramable intergrate circuit? Answered

hi everyone i need help on my rpm counter project..i had found a circuit that use lm2917 as frequency to
voltage circuit (2 output.-ve and +ve)...
now i need a pic that can compute the voltage to display onto the 8x2 lcd screen..
did someone know which type of pic that i should use?
could some one show me explain on how to pogram that circuit?
did someone have done this project that could share  a little knowledge to me?
i have a little knowledge in electronic..but i can understand english..thanks..



Best Answer 6 years ago

This is one of those koinkidinks... just before reading this headline i was reading this: http://dangerousprototypes.com/2012/01/18/using-micro-cs-built-in-libraries-to-drive-graphic-lcds/ (and it seems to be part of a series)

Now i realise you may want to "just" use a character display and not a full graphics but i thought the koinkidink-ness of this was like a sign so you get this url anyways ;-)

I hope it at least helps you in the right direction

thanks mh76dk for a very fast reply..actually i want to know what type of pic that i have to use..i.e icl 7107 or something else..can you suggest what type of pic that i can use?

A 7107 isn't a "PIC". To most here, PIC refers to a microprocessor.

As Skinnerz suggests, use a micro to measure the speed and drive the display. No extra ics, F to V chips etc are needed.

we meet again steveastrouk.. :) do you mean to use microprocessor just like the computer microprocessor?
is there another way that i cant use instead using the microprocessor.ie intergrated circuit? because with my budget..i dont have enough money to buy the tiny little micro thing..

If you are trying to build this on a budget, a microcontroller may not be the best option as you will also require a programmer (although once you have one, the chips are under £2 each). However, if you want to drive the LCD you will almost certainly need one.

Perhaps a better budget solution would be to get a counter IC, then a BCD to 7-segment converter, and use a 7-segment display instead of the LCD. If you use a 555 timer to reset the counter once every second, you will get the RPM on the display.

is there another option?like using the pic?is there a type of pic that ican use coz i would like to use lcd instead of pic for space reason..

If you really want to use a PIC, you will have to get a programmer, and write some code.

What exactly are the space requirements for the display? You should easily fit 4 or 5 7-segment digits in the same space as the LCD.

i have someone tht can pogrammed the pic..i just want to know what type of pic is hould use in my case..

If the programmer supports it, a 16F84, or a 16F84A is probably best, as it is fairly simple, and has a huge number of code examples and projects available online, including code to drive the LCD.

From the general comments and replies here, it seems you use the word PIC to mean something more general than most of us. I have almost no knowledge about LCD interfacing, and even less about analogue logic chips like a 7107 (it at least sounds like a analogue chip, without looking it up)

I notice some advice on doing it with 555's and Segment displays - those would probably be the cheapest alternative (and not require programming, uploading code to a chip (, debugging), and all that)

I could add that there is likely a handfull of other microcontrollers that would do the job aswell as PICs, some come with cheap (relatively) developmentboards, some boards even come with the LCD on it - so if you do not mind learning and spending a little money, choosing one of those could also work (i will not name any because the flamewars over this has a history of burning down datacenters, and i like instructables)

Anyways, from the emails ive gotten with comments, i think you can find a much simpler solution and cheaper than a programmable device from some of the more knowledgable people that posted them

(Im mostly good at writing a lot of text saying almost nothing, and im considering a career in politics - i just have a slight issue intimidating enough voters :( )

wait are you saing that a microprocessor is like this thing AVR ATtiny2313?
just like int this link below?

in this context, a microprocessor/microcontroller is exactly like that. a PIC is simply another brand (made by Microchip as opposed to Atmel for the attiny)

oo..missunderstanding..in thought micro-c and pic is diffrent function and product..it just a diffrend brand..is that right?..so in my case can you suggest what type of micro-c that i have to use?it still can be pogrammed just like pic right?

A number of PIC chips now have on-board ADC modules, which are fairly easy to use once the chip is set up properly.

Alternatively, why not just time rotation using the PIC, as it will be far easier to convert to a value to display.

As for writing to the display, you will save a lot of time and effort by using an LCD that conforms to the standard Hitachi driver (HD470?), and leave it in 8 bit mode.

You'll have to look up how to seperate the binary value for the RPM into individual decimal digits, but I suspect the simplest way is to subtract powers of 10 untill the zero bit is set.

in my thinking,i must have a some other circuit/pic that i can pogrammed to convert the value of voltage to code that make lcd display the output from the circuit..did you mean that i should use the pic that have ADC and already converted value for the lcd?
can you suggest the type of pic for my project..sorry i had very little knowledge in electronic ..thanks