Help Talking to LCD

Started by bsom21122 April 25, 2006
Well, I've gottan a few of thise LCD's from DOntronics in Australia
and I'm trying to get them to talk to my BasicX's but I'm not having
good luck.

I've tried Com1 and Com3, but I have been unable to get the screen to
respond. If I use my Parallax USBtoSER, the screen works great. I'm
stumped. I've used the serial LCD's from Parallax, et al. before, but
this screen is more complicated. When I read the PDF for the screen
before I purchased it, it looked like a piece of cake, but this is the
first time I've tried to use the BasicX's serial port functions. I
know I'm probably screwing up something easy.

Can anyone out there take a look at the document for this LCD screen
and give me some insight or possibly point out something I'm doing
wrong? It is located at:

http://www.dontronics.com/pdf/uLCD%20Users%20Manual.pdf

Thanks in advance...

//bsom
Do you have the 1K resistors between your RX and TX lines?

At power up you need to wait for 1000ms, then send a "U"
or chr(55) to the LCD so it can auto detect the baud rate.
Now you can send normal serial commands.

Chris

----- Original Message -----
From: "bsom21122"
To:
Sent: Monday, April 24, 2006 8:01 PM
Subject: [BasicX] Help Talking to LCD
>
> Well, I've gottan a few of thise LCD's from DOntronics in Australia
> and I'm trying to get them to talk to my BasicX's but I'm not having
> good luck.
>
> I've tried Com1 and Com3, but I have been unable to get the screen to
> respond. If I use my Parallax USBtoSER, the screen works great. I'm
> stumped. I've used the serial LCD's from Parallax, et al. before, but
> this screen is more complicated. When I read the PDF for the screen
> before I purchased it, it looked like a piece of cake, but this is the
> first time I've tried to use the BasicX's serial port functions. I
> know I'm probably screwing up something easy.
>
> Can anyone out there take a look at the document for this LCD screen
> and give me some insight or possibly point out something I'm doing
> wrong? It is located at:
>
> http://www.dontronics.com/pdf/uLCD%20Users%20Manual.pdf
>
> Thanks in advance...
>
> //bsom
>
Thanks, but what you said is almost verbatim from the manual. I've done
what the manual says without success. I'm looking for things which may
seem obvious to others but are missing or ill-explained in the manual.

My best guess is that something is not right with my signal ground. I
*think* the signal ground for the Com1 or Com3 serial should be Pin4,
right? I've got Pin4 tied to the ground pin on the screen. Could the
fact that I am powering the BasicX and the screen from two different
power sources play a role in this?

//bsom
Chris wrote:
> Do you have the 1K resistors between your RX and TX lines?
>
> At power up you need to wait for 1000ms, then send a "U"
> or chr(55) to the LCD so it can auto detect the baud rate.
> Now you can send normal serial commands.
>
> Chris
Usually, reading the manual is something most people haven't tried : )

Providing that you have a common ground what you have should work.
The only other thing I can think of is maybe you need to use inverted logic.
If that's the case then you would be forced to use com3.
Chris
----- Original Message -----
From: "bsom"
To:
Sent: Tuesday, April 25, 2006 7:18 PM
Subject: Re: [BasicX] Help Talking to LCD
> Thanks, but what you said is almost verbatim from the manual. I've done
> what the manual says without success. I'm looking for things which may
> seem obvious to others but are missing or ill-explained in the manual.
>
> My best guess is that something is not right with my signal ground. I
> *think* the signal ground for the Com1 or Com3 serial should be Pin4,
> right? I've got Pin4 tied to the ground pin on the screen. Could the
> fact that I am powering the BasicX and the screen from two different
> power sources play a role in this?
>
> //bsom
> Chris wrote:
>> Do you have the 1K resistors between your RX and TX lines?
>>
>> At power up you need to wait for 1000ms, then send a "U"
>> or chr(55) to the LCD so it can auto detect the baud rate.
>> Now you can send normal serial commands.
>>
>> Chris
>