Hi, for a class project we are trying to use an LK202-25-GW LCD to display some information sent out froma BS2 Stamp Microcontroller. We have had issues with the LCD only displaying garbage.
We tested it with a serial cable and using hyperTerminal, and it only displays garbage text, though it is consistent. We tried Hard Resetting the Baud rate, didnt change anything.
We have also used the provided BS2 code to try outputting text, and it outputs consistently, but the text isnot the right characters.
I read something about the fact that if it is set to TTL levels for the BS2, Hyperterminal will not work, but niether is working for us.
Any help anyone can provide would be greatly appreciated.
BTW, its revision 1.5
EDIT: Oh, and in case it matters, when we hook up the keypad, it doesnt respond to it at all (we centered it per the manuals instructions).
Problems using an LK202-25-GW
Hello bigred1521,
Thank you for your post. When connecting the BS2 Stamp to the LCD, the LCD needs to be set in TTL levels, unless there is a RS232 driver after the BS2. When the LCD is set to TTL levels, it will not work with Hyperterminal.
You mentioned that you tried hard setting the LCD, I wonder if you meant you tried what we call 'manual override' (section 1.7 of the manual). Manual override will reset the baud rate to 19200. If the LCD is set to RS232 right now, test with Hyperterminal again (of course set to 19200), The characters typed in Hyperterminal should display in the LCD.
Please let me know how things turn out.
Thank you for your post. When connecting the BS2 Stamp to the LCD, the LCD needs to be set in TTL levels, unless there is a RS232 driver after the BS2. When the LCD is set to TTL levels, it will not work with Hyperterminal.
You mentioned that you tried hard setting the LCD, I wonder if you meant you tried what we call 'manual override' (section 1.7 of the manual). Manual override will reset the baud rate to 19200. If the LCD is set to RS232 right now, test with Hyperterminal again (of course set to 19200), The characters typed in Hyperterminal should display in the LCD.
Please let me know how things turn out.
Raquel Malinis
Design and Development
Matrix Orbital
Design and Development
Matrix Orbital
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bigred1521
- LCD?
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- Joined: Thu Dec 01, 2005 7:21 am
We have no idea what it was set to when we got it (it had been in the lab, ha dbeen used once a year ago). So we did a "Manual Override" according to what the manual says, and it still wont work on either the BS2 or Hyperterminal.
Question though. If it is set to TTL levels, but the baud rate is now reset to 19200, does that mean it wont communicate with the PC because it is set to TTL levels, and it won't communicate with the BS2 because its Baud Rate isnt right?
Also, I know the commands to set the baud rate, so i can set it using the BS2 if thats possible (though I tried that before). One thing I do not know is how to turn on and off TTL levels.
Hopefully this helps.
Question though. If it is set to TTL levels, but the baud rate is now reset to 19200, does that mean it wont communicate with the PC because it is set to TTL levels, and it won't communicate with the BS2 because its Baud Rate isnt right?
Also, I know the commands to set the baud rate, so i can set it using the BS2 if thats possible (though I tried that before). One thing I do not know is how to turn on and off TTL levels.
Hopefully this helps.
Hi bigred1521,
On the LK202-25 borad, above the DB9 connector is the RS232 IC, and above it are 4 solder pads. From left to right, lets name the pads 1 to 4. If pads 1 and 3 are soldered, then the module is set to RS232. If the pads 2 and 4 are soldered, then it is set to TTL levels.
Again, if the LCD is set to RS232, try it out with Hyperterminal set at 19200, and do the manual override to make sure that the LCD will be the same as the Hyperterminal.
I am not quite familiar with the Stamp; I know we have a development board here and I see that it does not have an RS232 IC and therefore I conclude that it needs to talk to the LCD at TTL levels. Whether TTL or RS232, the baud rate must be the same inorder to communicate properly.
As per your question, if the LCD is set at TTL levels, it will NOT communicate with the PC (Hyperterminal); and if it is in RS232, the baud rate of the LCD has to match that of Hyperterminal inorder for them to communicate. With the Stamp, there should be a command to make its baud rate 19200.
To go from TTL to RS232 and back just means soldering-desoldering the pads I mentioned.
On the LK202-25 borad, above the DB9 connector is the RS232 IC, and above it are 4 solder pads. From left to right, lets name the pads 1 to 4. If pads 1 and 3 are soldered, then the module is set to RS232. If the pads 2 and 4 are soldered, then it is set to TTL levels.
Again, if the LCD is set to RS232, try it out with Hyperterminal set at 19200, and do the manual override to make sure that the LCD will be the same as the Hyperterminal.
I am not quite familiar with the Stamp; I know we have a development board here and I see that it does not have an RS232 IC and therefore I conclude that it needs to talk to the LCD at TTL levels. Whether TTL or RS232, the baud rate must be the same inorder to communicate properly.
As per your question, if the LCD is set at TTL levels, it will NOT communicate with the PC (Hyperterminal); and if it is in RS232, the baud rate of the LCD has to match that of Hyperterminal inorder for them to communicate. With the Stamp, there should be a command to make its baud rate 19200.
To go from TTL to RS232 and back just means soldering-desoldering the pads I mentioned.
Raquel Malinis
Design and Development
Matrix Orbital
Design and Development
Matrix Orbital
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bigred1521
- LCD?
- Posts: 3
- Joined: Thu Dec 01, 2005 7:21 am
Ok, I'll give this a try:
I'll resolder it to RS232 and See if it works in Hyperterminal (its already been manually reset, though I will probably do that again). If it is working then, then I will set the Baud Rate with the display program provided ont he website to 9600, then resolder it back to TTL and see if it is working on the BS2.
I'll resolder it to RS232 and See if it works in Hyperterminal (its already been manually reset, though I will probably do that again). If it is working then, then I will set the Baud Rate with the display program provided ont he website to 9600, then resolder it back to TTL and see if it is working on the BS2.