Thanks for that Steve.
I'll start with 200ohms. Just to double check that goes to the anode pin 15 right?
Dave (Mr Windy).
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Thanks for that Steve.
I'll start with 200ohms. Just to double check that goes to the anode pin 15 right?
Dave (Mr Windy).
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It does not matter, 15 or 16.
Dave
Always wear safety glasses while programming.
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Finaly managed to find five minutes to connect the back-light up using a 150ohm
resistor, however:
Before connection I had 4 lines of text. Then I connected the back-light which came on a nice blue colour but the text vanished. I then disconnected the back-light,the text didn't reappear, reloaded the program still no text (with or without the back-light on). I then loaded the program into my other 16F684 with the same outcome
Could it be the DATAUS number again?
Or something more worrying.
Dave
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Hmmm, from where do you pull the current for the backlight and is that supply rated/capable of supplying the current? Measure the voltage as you turn on the backlight and see if it sags.
Do you have a PAUSE at the beginning of the program to allow the LCD to boot up properly before writing to it? Something like PAUSE 1000 or whatever....
/Henrik.
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Hi Henrik
I've measured the voltage, it doesn't blip from 4.6v, even when the back-light is switched off - on.
I added the pause.Still no text showing.
Here's the program:
DaveCode:ANSEL = %00000000 'Disable analog select so ports work as digital i/o. CMCON0 = %00000111 'Disable analog comparators. TRISA = %00000000 'Set PORTA as OUTPUT. PORTA = %00000000 'Set PORTA pins all low. TRISC = %00000000 'Set PORTC as OUTPUT. PORTC = %00000000 'Set PORTC pins all low. DEFINE LCD_DREG PORTC 'PORTC.0 WILL CONNECT TO DB4, PORTC3 TO DB7 DEFINE LCD_DBIT 0 DEFINE LCD_RSREG PORTC DEFINE LCD_RSBIT 4 'PORTC.4 CONNECT TO LCD PIN4 DEFINE LCD_EREG PORTC DEFINE LCD_EBIT 5 'PORTC.5 CONNECT TO LCD PIN6 DEFINE LCD_BITS 4 DEFINE LCD_LINES 4 DEFINE LCD_COMMANDUS 2000 DEFINE LCD_DATAUS 75 DEFINE OSC 4 MAIN: PAUSE 1500 LCDOUT $FE,1,"*Hello WORLD*!" LCDOUT $FE,$C0,"I't WORKS!" LCDOUT $FE,$94,"I't WORKS!" LCDOUT $FE,$d4,"Oh dear it stopped!" GOTO MAIN
Last edited by LEDave; - 22nd April 2010 at 18:29.
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Hi Dave,
Try adding a LED to an unused pin and blink it a few times at start-up. Just to verify that the PIC is still actually executing code. Are you using an extarnal crystal or are you running on the internal oscillator?
If it appears to not executing code and you're using an external source for the osciallator then check and double check that.
/Henrik.
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Hi Henrik,
Will do.Try adding a LED to an unused pin and blink it a few times at start-up. Just to verify that the PIC is still actually executing code.
Internal oscillator.Are you using an extarnal crystal or are you running on the internal oscillator?
It does seem strange that the PIC wrote the test lines to the LCD then stopped when the back-light was fired up. It would be nice if it were something not too serious.
Dave
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Hi Henrik,
I've added the LED and pause to the program and no (unless I've made another mistake) the LED doesn't blink,so program not / stopped running? Program doesn't 'run' with the back-light turned off either.
Here's the code:
DaveANSEL = %00000000 'Disable analog select so ports work as digital i/o.
CMCON0 = %00000111 'Disable analog comparators.
TRISA = %00000000 'Set PORTA as OUTPUT.
PORTA = %00000000 'Set PORTA pins all low.
TRISC = %00000000 'Set PORTC as OUTPUT.
PORTC = %00000000 'Set PORTC pins all low.
DEFINE LCD_DREG PORTC 'PORTC.0 WILL CONNECT TO DB4, PORTC3 TO DB7
DEFINE LCD_DBIT 0
DEFINE LCD_RSREG PORTC
DEFINE LCD_RSBIT 4 'PORTC.4 CONNECT TO LCD PIN4
DEFINE LCD_EREG PORTC
DEFINE LCD_EBIT 5 'PORTC.5 CONNECT TO LCD PIN6
DEFINE LCD_BITS 4
DEFINE LCD_LINES 4
DEFINE LCD_COMMANDUS 2000
DEFINE LCD_DATAUS 75
DEFINE OSC 4
MAIN:
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 1500
LCDOUT $FE,1,"*Hello WORLD*!"
LCDOUT $FE,$C0,"I't WORKS!"
LCDOUT $FE,$94,"I't WORKS!"
LCDOUT $FE,$d4,"Oh dear it stopped!"
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 500
HIGH PORTA.5
PAUSE 500
LOW PORTA.5
PAUSE 50
GOTO MAIN
Last edited by LEDave; - 22nd April 2010 at 19:52.
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Well I changed the LCD_DATAUS n from 75 to 150 and the led fired up on PORTA.5, still no text on the LCD though.
Dave
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I would not think DATUS would cause the LED not to work...
Have you adjusted the contrast POT after connecting the back light? Maybe it is just washed out ?
Dave
Always wear safety glasses while programming.
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Hi mackrackit,
Yes, I've even disconnected the back light but can't see any text now, it hasn't reappeared.Have you adjusted the contrast POT after connecting the back light? Maybe it is just washed out ?
Dave
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I've cracked it...........!!!.....Yippeee.
PIN 5 onto LCD from PIC loose R/W.
Henrik, mackrackit, really sorry to have caused a problem.
The display looks great, bright but not too bright and the text is as clear as clear.
Dave
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If I only had a dime for everytime something like that has happened to me
Dave
Always wear safety glasses while programming.
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If I only had a dime for everytime something like that has happened to me
I don't think it'll be my last either...
Really pleased it's going though.
So a good place to start and get a grip / understanding of LCD display characters would be that link you posted earlier:
Interfacing an LCD with a project opens up so many possibilities, be it just instructions right through to displaying live information. I suspect it's not going to be easy but I'd like to get a grip on LCD's: They're seriously...
Dave
Last edited by LEDave; - 22nd April 2010 at 22:40.
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Yes, that link will show you how to do custom characters.
You will also want to look in the manual about how to place a normal character anyplace on the display along with different things that can be done with the cursor.
Dave
Always wear safety glasses while programming.
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I'm on it....
See you tomorrow.
Dave
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I had a go at loading a couple of custom characters with no success, so I thought I'd make my name move across the screen. Here's a part of the program.
The trouble is, on the third line down of the LCD (first square) my name also appears there. Could I when trying to load a custom character have inadvertently done something to the CGRAM setting? I then thought maybe it's the cursor so I turned that off with no joy, name moves across the screen still and also 1'st square third line.
Nice work on the website by the way.Code:MAIN: pause 1000 LCDOUT $FE,$0C 'Cursor off PAUSE 50 LCDOUT $FE,1," *" pause 500 LCDOUT $FE,1," *D" pause 500 LCDOUT $FE,1," *DA" PAUSE 500 LCDOUT $FE,1," *DAV" PAUSE 500 LCDOUT $FE,1," *DAVE"
Dave
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Part of the problem might be the 21 spaces on a 20 character screen??
Post you custom character code and we will see whats up.
Dave
Always wear safety glasses while programming.
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Hi mackrackit,
Oh dear, I can't even count up to 20 now
I've been working on my HEX today, maybe that explains it
Working a treat now thanks, 'again'.
It's not mine it's Darrel Taylor's, from that link you posted. It's the battery symbol.Post you custom character code and we will see whats up.
DaveCode:MAIN: PAUSE 500 LCDOUT $FE,$78,$06,$0f,$0f,$0f,$0f,$0f,$0f,$00 GOTO MAIN
Last edited by LEDave; - 23rd April 2010 at 22:37.
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The LCDOUT character stuff place at the beginning of your code, in the variable area.
Then in your loopCode:LCDOUT $FE,$40,$06,$0f,$0f,$0f,$0f,$0f,$0f,$00 'This is the first character #0 'The first place in the RAM is $40 'The next character would start with $48 VARS DEFINES ...
Code:MAIN: PAUSE 500 LCDOUT $FE,1,0 'First character LCDOUT $FE,1,1 'Second character if you have one GOTO MAIN
Dave
Always wear safety glasses while programming.
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Cheers mackrackit,
Things slowly starting to filter through. I'll have a look tomorrow.
I love the old LCD though, cracking.
Dvae
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Hi mackrackit,
Well I managed to get the program to do what I wanted it to do, namely run through four custom characters then place the four custom characters one in each corner of the display ( program code below).
All the info to do this was found within the LCD link you postedworks, what does the 128 part of it mean? I guess it must relate to LCD position HEX 0000 DDRAM Address for a 4 Line LCD but can't relate that to a CGRAM character position.Code:Row1 CON 128
Dave (lovin his LCD).Code:ANSEL = %00000000 'Disable analog select so ports work as digital i/o. CMCON0 = %00000111 'Disable analog comparators. TRISA = %00000000 'Set PORTA as OUTPUT. PORTA = %00000000 'Set PORTA pins all low. TRISC = %00000000 'Set PORTC as OUTPUT. PORTC = %00000000 'Set PORTC pins all low. DEFINE LCD_DREG PORTC 'PORTC.0 WILL CONNECT TO DB4, PORTC3 TO DB7 DEFINE LCD_DBIT 0 DEFINE LCD_RSREG PORTC DEFINE LCD_RSBIT 4 'PORTC.4 CONNECT TO LCD PIN4 DEFINE LCD_EREG PORTC DEFINE LCD_EBIT 5 'PORTC.5 CONNECT TO LCD PIN6 DEFINE LCD_BITS 4 DEFINE LCD_LINES 4 DEFINE LCD_COMMANDUS 2000 DEFINE LCD_DATAUS 150 Row1 CON 128 Row2 CON 192 Row3 CON 148 Row4 CON 212 DEFINE OSC 4 LCDOUT $FE,$40,$02,$06,$1a,$1a,$1a,$06,$02,$00 'FIRST CHAR 0 (Battery) LCDOUT $FE,$48,$06,$0f,$0f,$0f,$0f,$0f,$0f,$00 'Second CHAR 1 (Speaker) lcdout $FE,$50,$1F,$11,$15,$17,$17,$15,$11,$1F 'Third CHAR 2 (Copywrite) lcdout $FE,$58,$00,$0a,$0a,$00,$00,$11,$0e,$00 'Fourth CHAR 3 (Smiley) MAIN: PAUSE 500 LCDOUT $FE,1,0 'First character pause 1000 LCDOUT $FE,1,1 'Second character pause 1000 lcdout $FE,1,2 'Third character PAUSE 1000 lcdout $fe,1,3 'Fourth Character pause 1000 LCDOUT $FE,Row1+0,0 'Places CHAR 0 Top LHS of display. PAUSE 250 lcdout $FE,ROW1+19,1 'Places CHAR 1 Top RHS of display. PAUSE 250 LCDOUT $FE,Row4+0,2 'Places CHAR 2 Bottom LHS of display. PAUSE 250 LCDOUT $FE,Row4+19,3 'Places CHAR 3 Bottom RHS of display. PAUSE 4000 GOTO MAIN
Last edited by LEDave; - 25th April 2010 at 20:06.
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Each position on the display has a number for an "address".
By adding to the constant you can place the character anyplace you want on the display.Code:Row1 CON 128 = $80 Row2 CON 192 = $C0 Row3 CON 148 = $90 Row4 CON 212 = $D0 'All first position on each of the lines
First line third position from the left would be
$83 or 131
Setup a loop adding to the constant and see if you can make something scroll.
Dave
Always wear safety glasses while programming.
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Ah right (penny drops)
Mmm, I'll see what I can do.Setup a loop adding to the constant and see if you can make something scroll.
Dave
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I'm still working hard on this........!
I know what I need to do to get this to work (on paper as it were, I think I do anyway). I'm reading and GQQGLing like made to find and learn the programming skill I need to make it work.
If I can't crack it tonight I'll have to ask, tick, tick, tick....must dash.
Dave
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Well I did try.......
It was getting the LCD to output B0 as a DEC number (LCD location for the smiley) rather than just B0 that foxed me. I tried DEC B0 and a few other things ("."B0..."B0") but still no good. I think (and hope) I was on the right lines though.
Here's my attempt:
DaveCode:BO VAR BYTE 'BYTE 0 Sets position for CHAR 128...+19 LC var byte 'Loop_Count Counts 0 to 19 'positions' across display LCDOut $FE,$60,$00,$0a,$0a,$00,$00,$11,$0e,$00 'Smiley Face Pause 500 MAIN For LC = 0 TO 19 PAUSE 500 LET BO = 128 + LC 'Start at LCD Top LHS then add 1 to move across display LCDOUT $FE,1,B0,0 'Output the 'Smiley Face' at location B0 PAUSE 500 Next LC GOTO MAIN
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Reallllllly close
Made a couple smal changes
But there is still one small problem...Code:LCDOut $FE,$40,$00,$0a,$0a,$00,$00,$11,$0e,$00 'Smiley Face For LC = 0 TO 19 PAUSE 500 LET BO = 128 + LC 'Start at LCD Top LHS then add 1 to move across display LCDOUT $FE,1 LCDOUT $FE,BO,0 'Output the 'Smiley Face' at location B0 PAUSE 500 Next LC GOTO MAIN
I will leave that for you
Dave
Always wear safety glasses while programming.
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Well I compiled it and it ran........
Mmm, I've looked and looked and I can't see one. Was it from the original brief where you said use a CONSTANT and I've used a VARIABLE?But there is still one small problem...
Quick question. In the program you made the change of address from $60 to $40, that's because the Custom characters are given memory addresses $40.....$78 (Char 0 - 7) and they must be sequential right? In other words I had Character '0' at address $60 which was a mistake.
Also having the:
Simply clears the display on every loop so the next increment of LC moves the character along one and clears the previous character.LCDOUT $FE,1
Dave (Oop's what's next?)
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OOPPSS! Now I am the one that can not count. I have a 16x4 I use for testing. It would work for you 20x4 display.Originally Posted by LEDave
Yes, your were calling the wrong address.Quick question. In the program you made the change of address from $60 to $40, that's because the Custom characters are given memory addresses $40.....$78 (Char 0 - 7) and they must be sequential right? In other words I had Character '0' at address $60 which was a mistake.
Simply clears the display on every loop so the next increment of LC moves the character along one and clears the previous character.Can not have a character location after it, only display commands. But for spped you can do this, (a snippet from,,)Code:LCDOUT $FE,1
Code:LCDOUT $FE,1,"THE TEMPERATURE",$FE,$C0,"IS: ",DEC TRESULT,$FE,$90,"BAD READS ",DEC BCSI will get back to you with somethingDave (Oop's what's next?)
Dave
Always wear safety glasses while programming.
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Thanks for that mackrackit, a great help.
As and when mackrackit, we're all busy.I will get back to you with something
Dave
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Had to look over what we have done so far.
Serial
LCD
Some program flow.
Input from a switch
How about remembering something?
Let's say you have some parts moving along a conveyor and you want to count how many parts have passed by a certain point. But the problem is when the machine is turned off and then turned back on the counting starts back at zero and you want total parts counted for a week.
You can use the push button to simulate when a part passes by and have a WORD size variable increment each time the switch is activated and that value displayed someplace (serial or LCD).
To save the value for when the machine is turned off and on you will need to save the value to EEPROM and read from the EEPROM when the machine is started again. Place that value into the counting variable to continue counting from where it left off.
Another problem that can be addressed later is the EEPROM only has 1,000,000 write cycles so if the EEPROM is written to each time a part passes depending on how fast things are moving you could wear out the EEPROM in a matter of weeks.
So a shut down sequence is needed to only write to the EEPROM at shut down. This is not hard for scheduled shut downs but can be a "trick" for power failures.
For now you can have the value written to The EEPROM each time the variable is incremented.
Are you still using a 16F684 ?
Dave
Always wear safety glasses while programming.
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I'm a carer, I know a thing or two about remembering.....How about remembering something?
Yes still with the 16F684, do I need a more suitable chip?Are you still using a 16F684 ?
Just an aside here, I was looking at in the RS catalogue the other day, they have a PICKit2 for a good price. Is this the next one up for me? Or should I stick with the PICkit1 for now?
http://uk.rs-online.com/web/search/s...duct&R=0149613
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The 16F684 is fine for now. It all depends on what you need to do. More I/Os, memory, built in hardware? But for learning the small ones are good.
I am a big fan of the PicKit2 so if you can get one at a good price do so. But for now the PicKit1 is fine for the parts you are using. It is just very limited parts wise.
What do you have in mind to do with all of this? Home automation/monitoring?
There is so much that can be done with the "small" parts and they can be made to share information they may be all you need.
Dave
Always wear safety glasses while programming.
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You know I really don't have a direct answer to that one. I've got a couple of small projects in the offing (I'll tell you about them later) and some ideas.The thing is, it's almost unlimited in what you can do! For me right now, it's about building a sound knowledge base, plus it's really absorbing, fascinating, I love it.What do you have in mind to do with all of this? Home automation/monitoring?
Dave
Last edited by LEDave; - 27th April 2010 at 16:47.
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Hi mackrackit,
I've been busy working on the last assignment....
Quick question. Would the code (below) output the value of B_P onto my LCD? B_P is a VAR WORD. I've used DEC1 as I only want to test the output with a couple of button presses (if that makes sense).
DaveCode:LCDOUT $FE,1 LCDOUT $FE,DEC1 B_P
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Well... what did you get on your display?
Code:B_P = 12345 LCDOUT $FE,$C0,DEC1 B_P 'Displays 5 LCDOUT $FE,$C0,DEC2 B_P 'Displays 45 LCDOUT $FE,$C0,DEC3 B_P 'Displays 345 LCDOUT $FE,$C0,DEC4 B_P 'Displays 2345 LCDOUT $FE,$C0,DEC5 B_P 'Displays 12345 LCDOUT $FE,$C0,DEC B_P 'Displays 12345
Dave
Always wear safety glasses while programming.
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Hi mackrackit,
Really sorry for the late reply, has been one of those days today.
I've got a couple of small problems with LCD / Counting at the moment, nothing I shouldn't be able to fix by now so please bear with me. If I can't get it going soon I'll have to ask.
Dave
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Days???Really sorry for the late reply, has been one of those days today.
I have been having one of those weeks
Dave
Always wear safety glasses while programming.
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Hi mackrackit,
Lol..... Nice to know I'm not alone, you do have my sympathy though.I have been having one of those weeks
Here's what I thought was a silly question, now I'm not so sure it is:
When you declare a VAR WORD, I thought that the value would automatically be set at zero, now I'm not so sure it is. Do you have to have to re-set it to zero before you start a count program or is it zero already?
I know it's Friday tomorrow but I hope your week gets better.
Dave
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Sometimes it will be zero at power up but you never know.
You can use CLEAR, in the manual
or
VAR_IN_QUESTION = 0
Not a stupid question at all
Dave
Always wear safety glasses while programming.
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