Recommend LCD for use with 08M

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tariq_niazi

New Member
Greetings,

I am new to using LCD's with PICAXE's. I was searching online and found some really cheap HD44780 based LCD's. But I am not sure if the 08M is able to handle those or not. I have seen plenty of examples with 18x and above PICAXE's. Can anyone recommend any LCD that will work with 08M as I got many of them.

By the way here is the link for LCD's I found that I think are pretty cheap: http://411techsystems.com/html/lcd__s.html

- TKN
 
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rodmcm

Member
You need at least 6 outputs for to drive the LCD, so best to use 3 from the 08m to drive a shift register 74HC595 for five of these and the other from the O8M to drive the enter input to the LCD
 
W

westaust55

Moderator
Most bare/basic LCD modules utilise a parallel interface. This involves 8 bits for data and at least control signals. Many of these do allow transfer of the data in 4-bit nybbles with two data transfers per byte.
Even in the 4-bit data transfer mode you will need at least 6 IO pins to operate a standard parallel interface type LCD.
The other method which is far more economical of PICAXE IO is the serial interface method. This involves data being sent serially (asynchronously) via a single PICAXE output pin. The serial interface is a separate board that is connected to the standard LCD module.
The Rev Ed AXE033 is one such serial interface system and comes in a kit with a 2 line x 16 character LCD display.
I think that PH Anderson also makes a serial interface board. Have a look at his website.
IMHO, for a PICAXE 08M the serial interfaced LCD module is the only way to go.
Finding the serial interface board on its own will be more difficult than finding the LCD moduel although still not hard to locate.
 
B

BrendanP

Senior Member
Oately electronics LCD driver works well with picaxe and a lot of different LCD configurations. I've used it a lot. Might be a copy of Prof Andersons.
 
M

marcos.placona

Senior Member
A quick search (on google) for P H Anderson will return his website. There you will be able to find a serial module for less than a fiver, and with that you can interface with parallel LCD's via serial line.

I've been just using parallel with 4 bits (6 outputs), but heard about some people using PH Anderson's modules with great success.
 
M

MPep

Senior Member
2-wire LCD interface

Hi guys,
Elektor Electronics magazine had a circuit in their May 2008 edition that would suit. It only used 2 wires, data and clock, into a 4094.

The only problem, as previously mentioned, will be a lack of code space! With only 256bytes available, I would seriously doubt that you could do everything you want. In fact, to do initialisation and then transfer data, you will most certainly hit the 'ceiling' before all of this is done.

The 18X would be a much better choice.
 
M

Mycroft2152

Senior Member
marcos.placona said:
A quick search (on google) for P H Anderson will return his website. There you will be able to find a serial module for less than a fiver, and with that you can interface with parallel LCD's via serial line.

I've been just using parallel with 4 bits (6 outputs), but heard about some people using PH Anderson's modules with great success.
Click to expand...
As Marcos mentioned, PH Anderson's driver chip is definitely a winner. It is the easiest way to add a single wire seroal interface to an LCD. Using this chip leaves all the programming space open for your own program.

You can get the chip and a well designed pcb at Wulfden for only $9.

http://wulfden.org/k107/order.shtml

They work great, I have 3 of them!

Myc
 
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marcos.placona

Senior Member
MPep said:
Hi guys,
Elektor Electronics magazine had a circuit in their May 2008 edition that would suit. It only used 2 wires, data and clock, into a 4094.

The only problem, as previously mentioned, will be a lack of code space! With only 256bytes available, I would seriously doubt that you could do everything you want. In fact, to do initialisation and then transfer data, you will most certainly hit the 'ceiling' before all of this is done.

The 18X would be a much better choice.
Click to expand...
Hey, that sounds interesting. Is there anything published online with this sort of information?
 
hippy

hippy

Technical Support
Staff member
When I saw the Elektor article it seemed to be Myke Predko's 2-Wire LCD Interface without any credit given ...

http://www.rentron.com/Myke1.htm

My own take on that for the PICAXE is at ...

http://www.hippy.freeserve.co.uk/picaxe2l.htm

Some people have had luck with it, others have had to tweak things or go to three control lines. I've never built one myself so don't have any practical experience. The code there uses 85 bytes of an 08M's memory (33%).
 
M

MPep

Senior Member
You may be able to buy the article/edition on-line. Don't know sorry.

@Hippy,
I haven't studied Myke Predko's version as I wasn't aware of it.
I do, only now, recall seeing this method on your site. Just never put the 2 together.

The example code listed in the article appeared rather large. I haven't used it myself.
 
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