Advice on LCD display for Picaxe project.

[CDRIVE]

Constantine, you purchased a "SERIAL" LCD so how does that make any sense? That slave code for the AXE133 is intended to feed a bare LCD not a Serial LCD. Capice??

Sit tight. I'm going to post something for you to show you exactly what I'm talking about. It's sure to blow your mind! You're guaranteed to walk away realizing that you're making this more complicated than it is!

Chris

 

[CDRIVE]

I'm very tired over here, so I'm hitting the sack. Tomorrow morning I have to setup a new PC for my wife. I'm not looking forward to it as we don't work together well while messing with PC's.

Before I shut down I wanted to post this to let you sleep on what you see. I'll explain further tomorrow...If I'm still alive.
Chris

 

[HellasTechn]

Sir Chris, i am really, really sorry that i am getting you tired with this but please look here:
This LCD module is ment for use with Arduino not with Picaxe. Arduino use 2 wire communication for the LCD.
On the picture belos note J1, It has VCC,GND and also SDA, SCL as data transfer lines.

This will not work with a single line serial output from the Picaxe because they are for I2C serial communication which i dont know.

 

[CDRIVE]

I was tired because it was late when I posted that last night. Not because of your project. I like working on this.

OK, I think I see where the confusion is between the serial LDC you have and the one I used in my simulation. The model used in my simulation also uses a I2C buss. The main difference between your model and mine is that mine uses only a 3 pin input (VDD, VSS, RXD). It doesn't employ the fourth input (SCL) that you have. The SCL input on your model is a Clock input. According to the datasheet: Rx Data input is read on your SDA pin only after SCL switches High. You can read the complete description of the PCF8574T here..
http://www.ti.com/lit/ds/symlink/pcf8574.pdf
In particular read page 11, note 8. You will clearly see that the PCF8574 is not Arduino specific.

That said and from what I've gleaned from the PCF8574 datasheet you can't use the Axe133 wiring or code with your LCD. The Axe133 is a system of using a 18M2 to do the work that the PCF8574 does on your LCD. The alternative that you found using an 18M2 is just a user built version of the Axe133. It's intended to be used with a basic (parallel input) LCD.

This doesn't mean that you can't use your LCD though. You will need to create a program that follows the protocol described in the datasheet. The schematic won't look much different than the schematic I posted. It will be different only in that it will include an SCL pin. Of course I used a 08M2 to send the serial data because I really didn't need an 18M2 or 20M2 to merely send serial data.

One more note here. If you really wanted to use that 18M2 slave code with minimum pain you should have purchased a serial LCD with only 3 inputs (Vdd, RXD, Vss) because that's what the Axe133 and 18M2 slave code and circuit interface is equivalent too. Since your Chinese import was so cheap I don't think you're going to loose sleep over it though.

Chris

 

[HellasTechn]

One more note here. If you really wanted to use that 18M2 slave code with minimum pain you should have purchased a serial LCD with only 3 inputs (Vdd, RXD, Vss) because that's what the Axe133 and 18M2 slave code and circuit interface is equivalent too.

Such lcd display is not available on e-bay

Since your Chinese import was so cheap I don't think you're going to loose sleep over it though.

I have not

I will read the PDF you linked and get back to you. THANKYOU !!!

 

[CDRIVE]

I had no problem finding the datasheet for the MILFORD-2X16-BKP serial LCD that I used in my spice but haven't found a supplier. Even though Newark and Farnell supply the datasheet?!

I think? this is Greek. If it is you'll understand it. They're discussing the
MILFORD-2X16-BKP Serial LCD. Let me know.
http://kazus.ru/forums/showthread.php?t=54319

Chris

 

[CDRIVE]

Here's the datasheet..
http://www.farnell.com/datasheets/11357.pdf

Chris

 

[CDRIVE]

Constantine, what's the status of this project? Have you made any headway with your ebay GLCD? I ask because I have your PCF8574A spice model in my Picaxe-VSM library. With it I should be able to duplicate the I2C GLCD you have.

Chris

Chris

 

[HellasTechn]

Well i thought that since the Picaxe and the LCD works with I2C that is the way i will use it.

At the moment me and Ashley are preparing a code for an automatic dog feeder. This project requires the use of DS1307 RTC via I2C so when we finish the code we will add LCD support.

That is a good chance for my to learn how to use the I2c bus and should be fairly simple to interface with the LCD.