Pic12f675 + Pcf8574 + Lcd

[Bostjan]

Hello !

This is my first post here. I'm asking if it is possible to drive a standard 16x2 lcd via PCF8574 I2C I/O expander with PBP code directly.
I've done V and A meter with 2 channel ADC in PIC12F675 (0-50V, 0-5A) and I was thinking to output measured data on the LCD. The problem is the small number of I/O pins on the PicMicro. My idea is to use the I2C port expander. This type of controlling the LCD I saw on the net but was implemented in C programming language.
Any help will be apriciated !

[J. Mark Wolf]

I have used the PCB8574 extensively and I see no reason why it won't work.

It's a little convoluted and will be a little slow because you'll have to send an entire message to the PCF8574 just to wiggle one of it's output pins, etc.

You may want to consider the EDE702 chip, can't remember the supplier, do Google search) it's basically a smart LCD serial interface chip for just a few bucks. I think they're also available at JDR and/or Jameco.

[Acetronics2]

Hi, Bostian

No problem to do it ... a french speaking electronics magazine ( Elektor or Electronique pratique ...i'll look for, if you want ) has already published that idea ...

Just a bit boring sending bytes to the LCD, a bit slow also, but works perfectly.

Alain

PS: Note I2C LCDs are sold ready to use on the market ...

[Bostjan]

Thanks for your answers. I wish to use PCF because I have some. Can you give me some further info because I'm just trying to get into PicMicro programming. In short I'm a real beginner. I dont won't the finished code but just explanation in a few step by steb guide how to deal with my problem. I understend the operation with clasic conection LCD to PIC but I dont understend what data I have to send to PCF for making work the LCD. Please remember that I'm a begginer (mechanical engeneer) who wants to learn!

Thanks again for your help

[Acetronics2]

Hi, Bostjan

I Finally got it ...

Elektor magazine project 030060 ... see their site in the netherlands for an English version.

Alain

[Bostjan]

Thanks! I will look to this project.

[bbarney]

it's sept. 2003, let me know if you can't find it

[PJALM]

I found it here:

http://www.elektor-electronics.co.uk/Default.aspx?tabid=28&year=-1&month=-1&art=50459&group=Microcontrollers&PN=On&SearchText=#

But you have to pay to download the PDF.

[Bostjan]

I will try to find it in the local library. If I cant find it it is possible to obtain the article from you ?

Cheers

[bbarney]

Let me know ok
bbarney

[PJALM]

I don't have the article, I was also interested so I tried to search for it but that was all I could find. If I do find it I will post it here.

[mahatia]

Hello every body! I am a student, and I am trying to build a digital clock by using PIC12F675 as a microcontroler, one PCF8574, RTC DS1307, and one LCD 16x2 with mikroc langage. Have anyone some solution to program it? any help is apreciated! thank you very much! I need it a lot! I don't know how should I do! I must use these electronik components.

[Scampy]

Hello every body! I am a student, and I am trying to build a digital clock by using PIC12F675 as a microcontroler, one PCF8574, RTC DS1307, and one LCD 16x2 with mikroc langage. Have anyone some solution to program it? any help is apreciated! thank you very much! I need it a lot! I don't know how should I do! I must use these electronik components.

So why post on a forum that supports PicBASIC Pro ?

MikroElectronica have the own forums supporting their programming languages including MikroC - I would suggest you search their website or post on their forum for advice more suited to the hardware and programming environment you are using