AXE033 Display Problem

V

vk3gjm

New Member
Hi Guys,

I know this is a old thread, but the AXE033 serial display is frustrating. Let me explain.

To set the scene, I am using it with 20x2 on C.7 default internal clock.

I write the first line "hello", this is OK.

Move cursor to the start of at line 2 position 1, write "world", this fails at 192. If I increment line 2 position from 192 one position up to 193 and it writes "world" at the second position.

This is frustrating me, as I need to start "world" at 192 not 193.

If I use 192 for the second line the display is effectively blank, but you can see faint LCD activity that is not readable.

pause 500
serout c.7,n2400,("hello") ;as an example
pause 1000
serout c.7,n2400,(254,192) ;Move to the start at line 2 position 1
pause 1000
serout c.7,n2400,("world")

don't worry about the delay values, this was to try and understand if longer display serial write time is needed!

Does anyone have more insight to this simple problem?

Regards

Gerald
 
N

nick12ab

Senior Member
vk3gjm said:
I know this is a old thread, but the AXE033 serial display is frustrating. Let me explain.
Click to expand...
Then why did you post in it? The AXE033 has nothing to do with the Spark Fun serial LCD.

vk3gjm said:
If I use 192 for the second line the display is effectively blank, but you can see faint LCD activity that is not readable.
Click to expand...
The entire LCD or just the bottom line? Do you see the faint LCD activity continuously or just while 'world' is being written to the LCD then it goes blank?
 
E

eclectic

Moderator
@Gerald.

I've just tried your program from post #1.
(20X2 and AXE033 old model).

It works.

What happens when you try this program?
Code: 
pause 1000  

serout c.7,n2400,(254,1)  

pause 500

 serout c.7,n2400,(128,"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")
e
 
V

vk3gjm

New Member
Hi e,

A starts at second position of the first line and the second line starts at 1st position.

By removing (128,"abc.......Z)

a starts at the first line position 1 and O is at line 2 position 1.

Regards

Gerald
 
V

vk3gjm

New Member
Sorry about that.

I meant to write the following.

serout c.7,n2400,(128,"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ")

The main issue is, at least on the AXE033 module, 254,192, change a new line to line 2 position 1 does not work. However when you add the long string it does start at line 2 position 1.

I cannot help but feel there may be an error in the physical hardware I have, possibly the code in the PIC that takes in serial and drives the HD display.

Getting back to my initial post, I simply cannot get the following to work, although it should:-

pause 500
serout c.7,n2400,("hello") ;as an example
pause 1000
serout c.7,n2400,(254,192) ;Move to the start at line 2 position 1
pause 1000
serout c.7,n2400,("world")

You have tried it using a PICAXE 20x2 and AXE033, so I am confused also, as the code above is simple. Even a Mate had a look and confused him equally.

Regards

Gerald

VK3GJM
 
V

vk3gjm

New Member
Hi Rick,

+5V with less than 5mv ripple from a low noise linear power supply.

I have also tried at +5.2. Each are equal.

I will try i2C next.

Eclectric,

Yes the display works, eg line 2 pos 1 isn't dead.

I am just writing to picaxe support HQ.

Regards


Gerald

VK3GJM
 
Technical

Technical

Technical Support
Staff member
vk3gjm said:
I cannot help but feel there may be an error in the physical hardware I have, possibly the code in the PIC that takes in serial and drives the HD display.
Click to expand...
We agree there is a fault somewhere, but with thousands and thousands of AXE033 in the wild it is unlikely to be the firmware!

We think you have a faulty LCD, or faulty connection to the LCD. There is nothing wrong with your code. Send it back to us and we'll take a look.
 
V

vk3gjm

New Member
Hi All,

Mystery solved.

My AXE033 command for line 2 position 1 is (254,190). A far cry from the documented command of (254,192).

Regards

Gerald

VK3GJM
 
Technical

Technical

Technical Support
Staff member
Please can you a post a picture of your AXE033 and the brand of LCD fitted on it. Something strange here, as 192 is the standard.
 
V

vk3gjm

New Member
Hi Technical.

Yes I don't believe it either. It is what it is.

I cannot tell you the brand, the marking is a QA Pass sticker with several numbers such as:-

FECC7602E
GRNNYBW-66LE 1564.

Anyway it's working for now. I will purchase another display and try that to ensure AXE033 PIC image is not at fault.

Regards

Gerald
VK3GJM





HP-849x PICAXE project(VK3GJM).jpg
 
N

nick12ab

Senior Member
As the problem only seems to happen when rs is low, you should make a test program to find out if only location 192 is affected or not. The test program should clear the display, write a single character to the display (starting with location 128), pause for a second so you can see where the character is, then repeat but with the next character location.

Do all displayed characters work as well? No need to try this in all locations but if you try to display character 192, does that character get displayed (check the datasheet if available for a character map), or does something different get displayed?
 
V

vk3gjm

New Member
Hi Hippy and others,

Just moved onto another more urgent project.

I will try memory mapping and provide results. Might be in a week though.

Although the AXE033 serial display I have gave me grief, it works well in the project.

Also impressed with the lookup table I have implemented. As a matter of exploring, I may even try an EEPROM lookup as suggested.

The next task is a 28x2 and drive a 4x16 or 2x20 display via control lines.

Regards

Gerald
VK3GJM
 
You must log in or register to reply here.
Top