Picaxe 08M chip with a Phil Anderson LCD#117 – 2400 Baud LCD

jmmorgan

New Member
I am trying to use a Picaxe 08M chip with a Peter Anderson LCD#117 – 2400 Baud LCD driver (http://www.phanderson.com/lcd106/lcd107.html). It is a very simple hookup with Serial out (Pin 0) connected to the serial input of the LCD#117 unit. The program is as follows:
Symbol i=B0
Pause 1000
High 0
For I =1 to 5
Pause 10
SEROUT 0, T2400, (“?f”) ‘ clear screen
Pause 10
SEROUT 0, T2400, (“Hello”) ‘Display hello
Next i

Unfortunately, my LCD output looks like this
Hell
ello
Hello
Helo
Ello

Does anyone have experience with this LCD driver and have any suggestion what is wrong.

Thanks
John
 

pha555

Senior Member
Symbol i=B0

High 0
Pause 1000

Top:
SEROUT 0, T2400, (“?f”) ‘ clear screen
For I =1 to 5
SEROUT 0, T2400, (“Hello”) ‘Display hello
Pause 1000
SEROUT 0, T2400, (“?n”) ' new line
Next i
Goto Top

Please give this a try.

Peter Anderson, http:www.phanderson.com/picaxe
 

john2051

New Member
Hi,
I had a similar problem with an 08m and an axe033 serial lcd.

In the end the only way I could resolve this was using "Calibfreq" to change the 08ms oscillator sllightly.

Regards..John
 

jmmorgan

New Member
I played around with the Calibfreq a little more and I got it to work. It takes a value of 1. Thanks for all the help.
John
 

John West

Senior Member
It may be that the pic internal frequency generating circuit is off a bit (or the picaxe is.) Sometimes there are timing problems with the LCD as well.

I use a ceramic resonator with the Anderson chip, whether it is deemed necessary or not, in order to be certain of where any synchronization problem might be occurring. (Not that any given ceramic resonator can't be suspect.)

Always keep in mind that communication synchronization is a two-way street, and either device can be the problem. Having one device that can be adjusted is a real benefit when working with other devices that cannot be.

I'll keep the calibfreq fix in mind for future reference. Good info. Thank you.
 

julianE

Senior Member
I played around with the Calibfreq a little more and I got it to work. It takes a value of 1. Thanks for all the help.
John
I too tried the LCD#117 and had similar issues, once i ran the calibfreq 1 command the LCD worked well. I am surprised that two different 08M's had the same issue and the same value change in calibfreq fixed it.

Would it be wise to use the resonator on the LCD#117 chip?

I have the circuit set up on a breadboard for testing, I think I'll make it permanent and give it a try with other picaxe chips.
 

John West

Senior Member
As long as a tweak of the picaxe freq solves the problem (reliably) I see no reason to add extra components. Although significant temperature changes might cause some frequency drift problems that a ceramic resonator might be more immune to.

Hard to tell without some experimentation.
 
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