PICAXE 014M and LCD AXE133Y

peg

Member
Good morning

I am really struggling with LCD display. I have linked the H3 to AXE117 to the PICAXE B3 ouput pin and unable to get display. It is downloading. When I started I had the factory settings on display but now nothing. Got seperate voltage supply (4.5V ) to AXE117 and to LCD display. I am using flow chart option and selected B3 on LCD icon.
Thanks
 

Jack Burns

New Member
Hello and welcome to the forum.

Possibly a few different issues going on...

You no longer get the LCD start message, so this sounds as though you may have overwritten the PICAXE firmware code on the backboard of the LCD display.
Re-install the firmware directly to the jack socket on the back of the LCD.

Note: The firmware code is currently configured for an LCD, so if you’re using an OLED display then you need to change a couple of lines before re-programming the backboard.

This is the bit that needs changing, although you still have to program the PICAXE backboard with the full firmware code.

Code:
; ********************************************
; Note you must uncomment just one of these two options
; depending on whether you have an LCD or OLED module
;#define use_OLED
#define use_LCD
; ********************************************

So after changing the lines starting with #define, the OLED definition will become..
Code:
; ********************************************
; Note you must uncomment just one of these two options
; depending on whether you have an LCD or OLED module
#define use_OLED
;#define use_LCD
; ********************************************

To use the LCD you then write code which only needs to be downloaded to the 14m2, and that will have one of its outputs connected to the LCD H2 connector along with power and ground. See page 2 of the following document for further information.
https://picaxe.com/docs/axe133.pdf

Note: You MUST use an output directly from the 14m2 and NOT from the ULN2003A output. These are the connections between the 2 chips on the AXE117.
 

marks

Senior Member
For some 4.5v supply is too low to drive the logic controller of the LCD
it Vary's slightly with temperature which may explain why it works sometimes.
A 5.0v regulated supply is typically recommended.
 

peg

Member
Thank you - Yes I am using the pin outs directly from 14M2 - also check my power supply just 4.15V. Now do I try getting into school to pick up batteries lying on my desk and risk setting off all the alarms :)
 

peg

Member
Thank you everyone .Yes indeed the problem was I was using 2 power supplies 1 for PICAXE and one for LCD display but as you pointed out I had not linked the 0V of LCD to PICAXE. All working well now
Thanks again
 
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