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colesha
Joined: 09 Jan 2012
Posts: 45
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| RTOS with LCD for 16F887, LCD shows nothing |
 Posted: Sat Feb 08, 2020 2:39 pm |
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Hello,
I am trying to learn RTOS with pic 16f887 and i want to display some
characters on the LCD, but the LCD won't show anything. Below is the code:
| Code: |
#include <16F887.h>
#device ADC=10
#use delay(clock = 4000000)
#include <Flex_LCD420.c>
#fuses NOMCLR, NOBROWNOUT, NOLVP, INTRC_IO
#use fast_io(C)
#use rtos(timer = 0, minor_cycle = 50ms)
#task(rate = 250ms, max = 50ms) // 1st RTOS task (executed every 250ms)
void led1(){
output_toggle(PIN_C4);
}
#task(rate = 500ms, max = 50ms) // 2nd RTOS task (executed every 500ms)
void led2(){
output_toggle(PIN_C5);
}
#task(rate = 750ms, max = 50ms) // 3rd RTOS task (executed every 750ms)
void led3(){
output_toggle(PIN_C6);
}
#task(rate = 1000ms, max = 50ms) // 4th RTOS task (executed every 1000ms)
void led4(){
output_toggle(PIN_C7);
}
#task(rate = 1250ms, max = 50ms) // 5th RTOS task (executed every 1250ms)
void led5(){
output_toggle(PIN_D1);
}
void main()
{
lcd_init();
setup_oscillator(OSC_4MHZ); // Set the internal oscillator to 4MHz
output_C(0); // All PORTC register pins are zeros
set_tris_C(0);
printf(lcd_putc,"RTOS Test");
delay_ms(1000);
rtos_run();
}
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temtronic
Joined: 01 Jul 2010
Posts: 9225
Location: Greensville,Ontario
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| Posted: Sat Feb 08, 2020 3:37 pm |
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Does the LCD module function properly without the RTOS code ?
IE, the classic 'Hello World" program run ??
You should post which 'LCD' you're using.
Have to confirmed the wiring from PIC to LCD module IS the same as the default in the driver ?
Does the PIC actually run the '1Hz LED' program ?
I know it's not the driver as I use it and 4x20 LCD modules for past few years !
Jay |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19504
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| Posted: Sun Feb 09, 2020 1:19 am |
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General comment.
Always configure the chip _before_ loading things.
So:
| Code: |
#include <16F887.h>
#device ADC=10
#fuses NOMCLR, NOBROWNOUT, NOLVP, INTRC_IO
#use delay(clock = 4000000)
//First configure the chip
#use fast_io(C)
#use rtos(timer = 0, minor_cycle = 50ms)
//Now setup the port and RTOS
#include <Flex_LCD420.c>
//Next include the LCD & any other code
//Then the rest of the program.
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Historically you had to do this. The compiler now is more flexible on
letting things be done out of order, but it is still 'better' to work in this
order.
Now I repeat Temtronic's questions. Always get things working one
step at a time. Does the chip run and talk to the LCD?. There is no point
in starting trying to use the RTOS, until you have got the chip actually
working first. Test your LCD is working first.
Then a general comment. Have you got current limiting resistors on
the LED's?. These are required (not optional), and if missing or too small
will physically stop the chip running.
Your RTOS code posted will work. If it doesn't flash the LED's something
is wrong in the chip connections or the code to make the chip work,
not with the RTOS.... |
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PrinceNai
Joined: 31 Oct 2016
Posts: 479
Location: Montenegro
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| Posted: Sun Feb 09, 2020 5:30 am |
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Does the LCD turn on when you apply the power? You can see something changes on the LCD when you do it. I had some modules with + and - terminals reversed. The other thing I can think of is the contrast, maybe it works, but you just can't see it. And the last: you do use 5V power supply? On 3,3V those things mostly don't work. You haven't mentioned the LED's. Do they work as expected?
Samo |
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colesha
Joined: 09 Jan 2012
Posts: 45
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| Posted: Sun Feb 09, 2020 7:06 am |
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Sorry for the delay in response,
Sorry i didn't mention, I am running it on Proteus. The LCD displays well when i load a different code without the rtos.
The LEDs are working perfectly well as per the task assignment. I even tried using the 2x16 LCD but still the same. When i try to do a debug in Proteus, the code responsible for the display is skipped and goes directly to the rtos_run() line.
I have rechecked the code and i tried eliminating some lines below the LCD_init() and i found out that
| Code: |
setup_oscillator(OSC_4MHZ); // Set the internal oscillator to 4MHz
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was the issue. The new code is this:
| Code: |
#include <16F887.h>
#device ADC=10
#fuses NOMCLR, NOBROWNOUT, NOLVP, INTRC_IO
#use delay(clock = 4000000)
#use fast_io(C)
#use rtos(timer = 0, minor_cycle = 50ms)
#include <Flex_LCD420.c>
#task(rate = 250ms, max = 50ms) // 1st RTOS task (executed every 250ms)
void led1(){
output_toggle(PIN_C4);
}
#task(rate = 500ms, max = 50ms) // 2nd RTOS task (executed every 500ms)
void led2(){
output_toggle(PIN_C5);
}
#task(rate = 750ms, max = 50ms) // 3rd RTOS task (executed every 750ms)
void led3(){
output_toggle(PIN_C6);
}
#task(rate = 1000ms, max = 50ms) // 4th RTOS task (executed every 1000ms)
void led4(){
output_toggle(PIN_C7);
}
#task(rate = 1250ms, max = 50ms) // 5th RTOS task (executed every 1250ms)
void led5(){
output_toggle(PIN_D1);
}
void main()
{
lcd_init();
[b]/*setup_oscillator(OSC_4MHZ); // Set the internal oscillator to 4MHz*/[/b]
output_C(0); // All PORTC register pins are zeros
set_tris_C(0);
printf(lcd_putc,"RTOS Test");
delay_ms(1000);
rtos_run();
} |
The question is if i eliminate the setting of of the setup_oscillator(OSC_4MHZ) in the main, will it have any adverse effect on the performance?
Thanks for the responses, all were helpful. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19504
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| Posted: Sun Feb 09, 2020 8:00 am |
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Forget Proteus.
Read the 'sticky' at the top of the forum.
Proteus gives significant problems when you try to do anything at all
'complex' in terms of program flow.
Understand. It does not reliably work.
Change your clock settings to:
| Code: |
#include <16F887.h>
#device ADC=10
#fuses NOMCLR, NOBROWNOUT, NOLVP, INTRC_IO
#use delay(INTERNAL= 4000000)
#use fast_io(C)
#use rtos(timer = 0, minor_cycle = 50ms)
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This ensures the code does configure the oscillator to 4MHz.
The setup_oscillator is then not needed. |
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temtronic
Joined: 01 Jul 2010
Posts: 9225
Location: Greensville,Ontario
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| Posted: Sun Feb 09, 2020 8:35 am |
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well NOW we KNOW the problem.....
Proteus....
it's been busted, broke, nonfunctional for years...... |
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colesha
Joined: 09 Jan 2012
Posts: 45
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| Posted: Mon Feb 10, 2020 11:31 am |
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Thanks very much for the advice.
Let me purchase the components and set it up and forget about Proteu.s |
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