Interfacing LCD display with PICAXE

W

westaust55

Moderator
To answer your questions in reverse order:

1. 16x2 means a display with two rows each having 16 discrete characters. A discrete character display has small separation gaps between characters and differs from a gLCD (graphic LCD) display which typiclaly has a higher resultion but takes more effort in terms of conenctions and program to display characters. gLCD's can also display images (B&W on simpler types and colour of more expensive ones)

2. The display you provide a link to as a parallel interface LCD display whuich is fairly typical. This needs a minimum of 6 outputs from a PICAXE chip to interface directly between the PICAXE and LCD

Some further information:
There are various companies that sell either complete LCD kits or backpacks to enable one to use a single serial output from a microcontroller such as the PICAXE.
Rev Ed sell the AXE033 and AXE133 kits.
Sparkfun and others also sell serial interface kits either as a “Backpack” interface only or a kit with the interface and LCD..
 
hippy

hippy

Ex-Staff (retired)
The LCD appears to have a parallel interface so it should be possible to interface to a PICAXE but they normally require a minimum of six control lines or external hardware to provide the control lines. There appears to be no datasheet for that display so it's impossible to say what its actual requirements are.

We would recommend the AXE133 or AXE133Y for connecting to an 08M2 -

www.techsupplies.co.uk/AXE133
www.techsupplies.co.uk/AXE133Y

16x2 means there are two lines on the display which can display 16 characters per line.
 
W

westaust55

Moderator
If you wish to proceed with a PICAXE 08M and a basic parallel LCD as per your link you will need some form of interface.

Rev Ed sell the FRM010 chip for UK£4-00 (+postage) which can handle the requirements for you.
See here: http://www.picaxe.com/docs/frm010.pdf
and: http://www.techsupplies.co.uk/epages/Store.sf/en_GB/?ObjectPath=/Shops/Store.TechSupplies/Products/FRM010


If you change to a 28X1 then you will have 8 pins predefined as outputs and can re-allocate some port C pins as well as outputs if your project needs more outputs.
With any PICAXE chip having sufficient pins, that is at least 6 outputs no interface chips is needed for a parallel connection.

The difference:

If you use an LCD with a serial input, not only do you only need just 1 PICAXE output, but you can use the inbuilt SEROUT command for the serial comms to the LCD.

If you use a parallel interfaced LCD you need to add your own subroutine to pass the characters (as data) to the LCD display. There are plenty of example subroutines posted on this forum to copy from.

Keep in mind that a few folks do seem to come to grief initially trying to get parallel interfaces working.
That Hobby-2-go and many E-Bay LCD offerings do not indicate which controller protocol it uses. Most use the Hitachi HD44780 protocol for commands but not all.
 
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