LCD help, think I''ve done something wrong but not sure!
Archiver
Posts: 46,084
Hello, I was wondering if anyone could help?
I have just got my hands on the blue and white LCD 20 X 4 from
Parallax. It is the LK204-25-WB.
I hooked it up to my serial port and modified a power connector to
the correct pin out and with 5V. I connected the ground of the power
supply to the ground of the serial cable. The screen turns on and I
get the flashing cursor in the top left of the screen. Perfect.
Looks really good by the way!
The problem comes when I try to send data to it. I tried the Matrix
Orbital Tester Online software that came with it.
When I write the word "test" and send it to the module the result on
the screen is "QSt||"
I have tried it on the Com 1 and Com 2 port and tried 2 different
straight through cables. The port setting for both is 19200 baud rate
and no flow control. I have tried it with software flow control as
well, with the same result. If I try hardware flow control
everything slows down on my PC.
I have checked the jumper settings on the board and have also tried
everything at 9600 baud with exactly the same result.
I then tried to just type in the box at the top of the Matrix Orbital
Tester Online which I assume gives a real time display on the LCD of
whatever you type. The results were as follows:
Typed: Output:
Q w
7 d
Z )
1 g
G ¥
I have also found that the following commands have the following
results:
8 Clear Screen
x Backspace
X Line Feed.
One more thing is that when typing data to the LCD it displays it
first on line 1 then line 3 then 2 and then 4.
Is this correct?
The backspace and line feed work as expected (Lines 1,2,3 then 4) but
every other key will follow the 1,3,2,4 sequence.
It looks to me that the data is being corrupted or mis-interpreted in
some way.
I have also tried the a reset procedure but this has made no
difference.
I have also tried to control it via Hyper term but every time I tried
to connect, Hyper term just crashed as though there was a COMMS
error. I tried to connect another serial device to the serial port
and that worked fine.
I have got a sneaky feeling that I have overlooked something silly
but at 3:30 this morning the coffee and curry powered brain finally
gave up!
Can anyone help? Is it something I am doing wrong or could it be
that there is a fault with the LCD?
TIA
/A
I have just got my hands on the blue and white LCD 20 X 4 from
Parallax. It is the LK204-25-WB.
I hooked it up to my serial port and modified a power connector to
the correct pin out and with 5V. I connected the ground of the power
supply to the ground of the serial cable. The screen turns on and I
get the flashing cursor in the top left of the screen. Perfect.
Looks really good by the way!
The problem comes when I try to send data to it. I tried the Matrix
Orbital Tester Online software that came with it.
When I write the word "test" and send it to the module the result on
the screen is "QSt||"
I have tried it on the Com 1 and Com 2 port and tried 2 different
straight through cables. The port setting for both is 19200 baud rate
and no flow control. I have tried it with software flow control as
well, with the same result. If I try hardware flow control
everything slows down on my PC.
I have checked the jumper settings on the board and have also tried
everything at 9600 baud with exactly the same result.
I then tried to just type in the box at the top of the Matrix Orbital
Tester Online which I assume gives a real time display on the LCD of
whatever you type. The results were as follows:
Typed: Output:
Q w
7 d
Z )
1 g
G ¥
I have also found that the following commands have the following
results:
8 Clear Screen
x Backspace
X Line Feed.
One more thing is that when typing data to the LCD it displays it
first on line 1 then line 3 then 2 and then 4.
Is this correct?
The backspace and line feed work as expected (Lines 1,2,3 then 4) but
every other key will follow the 1,3,2,4 sequence.
It looks to me that the data is being corrupted or mis-interpreted in
some way.
I have also tried the a reset procedure but this has made no
difference.
I have also tried to control it via Hyper term but every time I tried
to connect, Hyper term just crashed as though there was a COMMS
error. I tried to connect another serial device to the serial port
and that worked fine.
I have got a sneaky feeling that I have overlooked something silly
but at 3:30 this morning the coffee and curry powered brain finally
gave up!
Can anyone help? Is it something I am doing wrong or could it be
that there is a fault with the LCD?
TIA
/A