Matrix user forums

Hello,
I have an E-block (i.e. LCD board, EB-005-00-3). I am building a circuit for micrcontroller in the bread board and I am trying to use it. I have attached a picture for you to see. One can see there are 16-pins outside. I think I can use these pins for connecting this LCD board in a breadboard circuit. Can anyone help me to find data sheet for this board?

Hi Kalim!



Here you can find all about this: http://www.matrixmultimedia.com/product ... PHPSESSID= Look under Resources All kind of datasheets.


Best regard


Jorgen

Thanks a lot!!

somehow I could not find it from this website.

Hi Kalim
Not sure if your aware but if you look at the top right of the forum screen next to logout theres a link to the main matrix siteclick on it then click the eblocks icon, then click the circuitboards icon and you can then select the eblock you need then the pdf for that eblock

Regards
Dazz

Dazz,
I have seen that. Thanks again. Correct me if I am wrong, I have looked at the data sheet and found following information:

1. According to page 7 of data sheet, if I move jumper from default to Patch, I can use P1 side pins (i.e. BIT0, BIT1, BIT2, BIT3, RS and E) for connecting this LCD board with microcontroller in breadboard.
2. I have to connect powersupply in J1 port.

If you have any suggestions, please let me know. I do not want to fry the LCD board.

Hello,

Yes if the patch system jumper is in the patch setting then you can simply wire across your signals. Ensure that the +V and GND signals are also brought across to the screw terminals. As long as +V and your microcontroller I/O is 5V or less you shouldn't have any issues. Also keep in mind the cable lengths cannot be too long. If they are longer then say 20cm then you will start to get transmission line problems such as reflections which will stop the display working correctly.

Very good advice regarding length. I will keep this information in mind. Thank you!!

I have couple of questions although I am not sure this is the right forum or not.

1. I tried to connect a keypad in port A (I am using PIC16F877A). I found last two rows could not be connected. When I connect port B, everything (all column and row) connects fine. Why?
2. In order to connect keypad (4 x 4), do I have to use resisters from column/row to ground, or I can simply connect to any ports?

Any suggestions will help.

Hello,

On the 16F877A the port pins RA4 cannot source current and RA6 and RA7 do not exist. Therefore you cannot use the Keypad on PortA.

Ports B, C and D should all work ok.

If you refer to the schematic for the EB014 in the E-block datasheet then it will show you how this keypad is wired up and therefore how you can create a 4x4 keypad.

Thanks!! I understand.

One more question in this area. When I used port B for keypad input. Does it have internal pull up resister? If there is an internal pull up, I do not need to add external resistor in the breadboard.
I am adding a picture of keypad connection here. I have changed many times from row to column, column to row. Nothing worked. Sometimes, I saw few dot/symbol/unrecognizable symbol appears in receiver side LCD.

Any suggestions will be appreciated.

Hello,
I have made some progress on this project (i.e. serial data transfer). I have tested keypad and LCD panel. Both of them work fine. You can watch youtube link here:

http://youtu.be/fEMW8hGGJdY

But main program that I am trying to develop is still not working. Let me explain what I am trying to do. I am reading keypad from transmitter side. And want to read and display that data on receiver side.I wrote one program to read keypad value and transmitt using RS232 and another program to read transmitted data and display value in LCD pannel. So, basically there are two circuits and I connected them from pin 25 (in transmitter side) with pin26 (in receiver side).

I have attached both file here for you to see. Please let me know if you can help you.

Hi Kalim!

I don´t know if you want to read the value from the keypad or the number on the top of the bottom of the keypad But I have made some changes in your program. I have not done test "in real world". But it should now show the value from keypad in the display. Hope it work´s.

Best regard

Jorgen.

Jorgen,
Thanks for your time and for your post. I actually found that in my transmitter side, microcontroller was not sending anyting in pin25 (Tx). So, I made changes there and finally solved the problem of serial data transmission. You can see the link here: http://youtu.be/S4A_3iyDJdg