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Connecting two-YMC-KS CFA634 to pc

er__carlos20

New member
I changed the power connections connect only the J2 now 1 and 3, instead of 1a negative to positive 2 and 3, the only change we noticed is that now, when the backlighting is only connected by RS232, and when I connect or changing programs or open corrects ports, it is when turned on, if not shut down, but I still get the display shows something more than the blinking cursor,

What solutions can give?
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... the only change we noticed is that now, when the backlighting is only connected by RS232, and when I connect or changing programs or open corrects ports, it is when turned on, if not shut down, but I still get the display shows something more than the blinking cursor...
I do not understand what you mean. Can you try to say it differently, and maybe the translator will give a better result.
 

er__carlos20

New member
sorry, i try in my english .

lcd is On when J2- 1 and 3 and rs232 are connected and ports opened.
when ports are closed or programs descativated lcd is off

before lcd is on when J2 1,2, and 3 are connected , with or without rs232,

but i cannot display any screen I choose only cursor

I hope you understand better
 
lcd is On when J2- 1 and 3 and rs232 are connected and ports opened.
when ports are closed or programs descativated lcd is off
Yes, J2-1&3 supply LED power to backlight.
Port opened = supply power to controller chip via RS232 DTR or RTS signal.
before lcd is on when J2 1,2, and 3 are connected , with or without rs232,
Yes, because J2-2 supplies power to controller chip, so RS232 power is not needed.
but i cannot display any screen I choose only cursor. I hope you understand better
So there is still a communication problem. The serial signal is either not reaching the display, or the baud rate is wrong.

Look at the data sheet file, on page 29 which shows the jumper and switch locations. Please post here what the jumper and switch settings you have.

When the display is first applied power, what is printed on the screen? Please post here what text the screen shows at power on.
 

er__carlos20

New member
i have two lcds

1 is 1 off, and 2 on = 9600bd
2 is 1 off , and 2 on = 9600bd

the main screen from lcd 1 is the eeprom test
and the main screen of lcd 2 is the logo of crystalfontz,
 
the main screen from lcd 1 is the eeprom test
and the main screen of lcd 2 is the logo of crystalfontz,
That is not enough detail information. I want to check what baud rate is shown on the screen, and that it matches what the switches are set to. I wonder why both LCD do not show the same boot screen.

Also, you did not say how the jumpers are open/closed. You want to know why I ask this? I suspect your PC serial port is not sending because the CTS and DSR signals are not enabled. To enable these signals, jumpers JPC and JPD would need to be closed (or you could jumper pins 4-to-6 and 7-to-8 on your serial cable).

This could easily be verified if you had test equipment; otherwise it is trial-and-error to find the problem.
 

er__carlos20

New member
the screen is different because they use the bootsetup and load default settings eeprom, only an LCD.

baud rate shown on the screen are the same as the connector indicates when the display change to 19200 sample 19200 and when is 9600 sample 9600.

the last part you said about the jumpers do not understand very well. is on the plate where I would talk on the cable or rs232 where we should check


edit:

When you say: you could jumper pins or 4-to-6 and 7-to-8 on your serial cable

means that I have to solder a wire between two pins and put them together? or that I should swap the positions of the wires and the pin 4 to pin 6 and pin 6 pin 4?
 
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the screen is different because they use the bootsetup and load default settings eeprom
Before this, you said you tried to use the boot setup program, and you said the display did not respond. I don't understand how you change the boot screen if you have no communication.
When you say: you could jumper pins or 4-to-6 and 7-to-8 on your serial cable means that I have to solder a wire between two pins and put them together? or that I should swap the positions of the wires and the pin 4 to pin 6 and pin 6 pin 4?
Solder a wire from pin 4 to pin 6 and also another wire from pin 7 to pin 8. Do not swap the pins.

Instead of soldering the wires to pins, you can solder the jumpers on the rear of the board, JPC and JPD. That will provide the same result.
 
USB LCD Displays - Graphic and Character LCDs with a Keypad

er__carlos20

New member
I also understand and change the home screen,

and cables should be in the two connectors??? or do one of the sockets is enough?

I mean, 4 and 6 wire and cable 7 to 8 in a single plug, or the same operation x2
 
I also understand and change the home screen
If you can change the home screen, then there is no communication problem, and no reason to continue with this thread.
... and cables should be in the two connectors??? or do one of the sockets is enough? I mean, 4 and 6 wire and cable 7 to 8 in a single plug, or the same operation x2?
Just 1 plug. But if you solder the JPC and JPD on the board then it can work for any cable.

If you can change the home screen, there is no reason to do this.
 
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