Wake up LCD !!

[ttbuddy]

Hi ttbuddy,
Could you check LM2936-3.3 output is 3.3V, I thought the Ic connect wrong way,also seem RB4 not connect to E LCD pin

Well I use a battery source of 9V (measured to be 8.6V)
and the output from the LM2936-3.3 strangely is 8.0V !!
EDIT:
I just found out that I got lm2936z-5 .....
but the output still over 5V ...
I think not much different between 3.3V and 5V as both LCD and PIC may consume ~5V.

 

[ericgibbs]

Well I use a battery source of 9V (measured to be 8.6V)
and the output from the LM2936-3.3 strangely is 8.0V !!
EDIT:
I just found out that I got lm2936z-5 .....
but the output still over 5V ...
I think not much different between 3.3V and 5V as both LCD and PIC may consume ~5V.

hi,
If you have had 8V to the PIC and/or LCD they just maybe damaged.

 

[ttbuddy]

hi,
If you have had 8V to the PIC and/or LCD they just maybe damaged.

Well ... i will test the PIC and LCD soon ...
PIC is still manage to write, read and erase ....
and the LCD i will try with my friends ....

EDIT:
By the way ... the diagnostic test successfully shows 0123456789 on the LCD .....
So i think nothing wrong with the PIC and LCD....

And I'd tested on my project as well.....i finally saw this appear:
**broken link removed**

Thanks ericgibbs, five0, and mister_e so much.
Reputation given.

Well I also not sure what happened actually ... i will figure it out ...

 

[Sajen]

Hi

I need to make one voltmeter using JHD162A LCD display. Can you guide me

 

[klein_wang]

Hello ,I am the new guy for this forum , we are LCD manufacturer in China . Any questions about LCD product ,please contact with me , we are willing to tell what we know .

 

[Sajen]

Hi,

Hi,

I need to build a voltmeter using JHD 162A LCD with HD44780U driver or any other suitable driver. Please help me on it.

 

[ericgibbs]

Hi,

Hi,

I need to build a voltmeter using JHD 162A LCD with HD44780U driver or any other suitable driver. Please help me on it.

hi,
If you read thru this thread you should find enough information to start your project.
The thread has wiring diagrams and programs.

 

[ttbuddy]

hi,
If you read thru this thread you should find enough information to start your project.
The thread has wiring diagrams and programs.

Well...i think this thread is more on wattmeter ... hehe
Oh by the way, seems like although i have the characters appear on my LCD, the wattmeter is not yet fully functioned as i tried to connect a resistor of 1K as the load, it doesnt sense anything to me! Well, i use the 1 Ohm as my shunt resistor.

Thanks if can help.

By the way, to ASM experts, may i know what data is contained for each of the 4 data buses connected to the LCD?
Urgent help needed....as i needed to decode it on the other module...thanks

 

[ericgibbs]

Well...i think this thread is more on wattmeter ... hehe
Oh by the way, seems like although i have the characters appear on my LCD, the wattmeter is not yet fully functioned as i tried to connect a resistor of 1K as the load, it doesnt sense anything to me! Well, i use the 1 Ohm as my shunt resistor.

Thanks if can help.

By the way, to ASM experts, may i know what data is contained for each of the 4 data buses connected to the LCD?
Urgent help needed....as i needed to decode it on the other module...thanks

hi,
As you are using only 4 wires for the data connections to the LCD from the PIC, the data/commands have to be sent as two 4 bit nibbles.

The command codes are written with a command write code and the data [ displayed characters] are ASCII.

Two other wires are required for the RS and Enable lines, sometimes a third wire is used for the RW line.
Depending upon the LCD type a Contrast pot maybe required.

This is a good reference and also Nigels tutorials.
**broken link removed**

 

[ttbuddy]

hi,
As you are using only 4 wires for the data connections to the LCD from the PIC, the data/commands have to be sent as two 4 bit nibbles.

The command codes are written with a command write code and the data [ displayed characters] are ASCII.

Two other wires are required for the RS and Enable lines, sometimes a third wire is used for the RW line.
Depending upon the LCD type a Contrast pot maybe required.

This is a good reference and also Nigels tutorials.
**broken link removed**

Well, thanks so much for the reference. At least I found something useful. By the way, beside the character set and the instruction set for the driver, there is ASM code which is used to drive the driver right? Based on the ASM code here, may I have some clue on what is being sent to the driver before the character is being displayed? Is the code to drive the driver or it holds the actual ASCII characters? I am using 16x2 LCD,
As I will connect this two data buses to another module, so without the driver, will I get the characters as well? Thanks

 

[ericgibbs]

Well, thanks so much for the reference. At least I found something useful. By the way, beside the character set and the instruction set for the driver, there is ASM code which is used to drive the driver right? Based on the ASM code here, may I have some clue on what is being sent to the driver before the character is being displayed? Is the code to drive the driver or it holds the actual ASCII characters? I am using 16x2 LCD,
As I will connect this two data buses to another module, so without the driver, will I get the characters as well? Thanks

Im not sure exactly you are asking, but a summary may help.
After power up, the LCD ic HD44780 MUST be initialised to the type of data ie 4 or 8 bit, also number of rows, fonts, cursor setting and the shift action.

If this is done correctly, you can write and ASCII data character to the LCD and it will display it on the top row, first column.

Writing another ASCII data char will display on the 2nd column and so on.

If you want to write a particular location on the LCD, you write a command code setting the coordinates
ie, line address and offset from column number one.

Control codes can be use to clear the screen, home the cursor, select the row etc.

Why dont you post your code, with comments, so that we can determine the area thats causing you a problem.

 

[ttbuddy]

OK, so beside the initialization of the LCD, basically that two 4-bits lines from PIC are used for ASCII character display? Means if i connect to the IO of another module, it will display the character via Hyper Terminal for example? The code is here. Really appreciate for the help.

 

[ericgibbs]

OK, so beside the initialization of the LCD, basically that two 4-bits lines from PIC are used for ASCII character display? Means if i connect to the IO of another module, it will display the character via Hyper Terminal for example? The code is here. Really appreciate for the help.

Hyper term and a LCD are totally different animals, they are not compatible.

If you want the PIC to talk to the Hyper term you need a UART routine in the PIC.

 

[Nigel Goodwin]

That code doesn't include the LCD code, it's in a separate file and linked as an INCLUDE file.

But why are you messing with that fairly involved code for a wattmeter when you want to make a simple voltmeter?.

My tutorials already do all you need.

 

[ttbuddy]

Hyper term and a LCD are totally different animals, they are not compatible.

If you want the PIC to talk to the Hyper term you need a UART routine in the PIC.

Erm...ok i make it like this:
Basically at first I was having my watt meter connected to the LCD.
But because my project is on automatic meter reading like, so instead of connecting to the LCD, now i make use of the 2 pins from the PIC and connect to the digital IO of a module (which contains antenna for data transmission). Then it sends to the base, from the base i have it connected to my PC using the USB. So i was wanting to know the type of data i can have over the hyper terminal at the computer.

 

[ttbuddy]

That code doesn't include the LCD code, it's in a separate file and linked as an INCLUDE file.

But why are you messing with that fairly involved code for a wattmeter when you want to make a simple voltmeter?.

My tutorials already do all you need.

Erm...I am doing watt meter by the way, sorry as i am in the stage of learning.
Here is the LCD include file:

 

[ericgibbs]

Erm...ok i make it like this:
Basically at first I was having my watt meter connected to the LCD.
But because my project is on automatic meter reading like, so instead of connecting to the LCD, now i make use of the 2 pins from the PIC and connect to the digital IO of a module (which contains antenna for data transmission). Then it sends to the base, from the base i have it connected to my PC using the USB. So i was wanting to know the type of data i can have over the hyper terminal at the computer.

What format does the RF module expect as an input, the HyperTerm is RS232 on a PC.????

 

[ttbuddy]

What format does the RF module expect as an input, the HyperTerm is RS232 on a PC.????

Well, here is what expected for the IO input (pin17-20):
**broken link removed**
For the Hyper terminal, it is using the USB interface.
P/S: I am connecting to pin 17~20 from the pic:
**broken link removed**

 

[ericgibbs]

hi,
For the type of PIC you are using the UART is the best option to communicate with the RF Module.
You require a RS232/UART routine in the PIC program.

 

[ttbuddy]

hi,
For the type of PIC you are using the UART is the best option to communicate with the RF Module.
You require a RS232/UART routine in the PIC program.

Erm... thanks again.
Did you mean UART connection made to pin 2 or 3?
So the normal connection to pin 17~20 is in vain?
Sigh .....

Is UART routine needs lots of modification to the PIC?
Sorry again as I am weak in ASM programming.

So i need any interrupt service routine alike codes?

        ; 8-bit asych mode, high speed uart enabled
        movlw    0x24   ; BRGH=1  20=BRGH=0
        movwf    TXSTA

        ; Serial port enable, 8-bit asych continous receive mode
        movlw    0x90
        bcf      STATUS,RP0
        movwf    RCSTA