| View previous topic :: View next topic |
| Author |
Message |
treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
|
| pin timing of 16F887 |
 Posted: Wed Jun 10, 2009 5:07 pm |
 |
|
CCS Ver 3.249 18F452/16F887 running at 18.432000MHz
I'm debugging why my LCD isn't working on port A.
Code runs OK with 18F452 but if I swap to 16F887 it doesn't.
Looking at pin A0 with scope the 18F452 makes a 30uS wide signal but the 16F887 is much smaller, 1.4uS. Can anyone tell me why?
| Code: | #include <18F452.h>
//#include <16F887.h>
#use delay(clock=18432000)
#use rs232(baud=1200,errors,xmit=PIN_C6,rcv=PIN_C7,parity=e,enable=PIN_C5,stream=CIM)
#use rs232(baud=19200,xmit=PIN_D7,invert,stream=DEBUG)
#case
#zero_ram
#define LCD_RS PIN_A0 //<-- oscope on this pin, other have simular width
#define LCD_E PIN_A1 //note no RW
#define LCD_DB4 PIN_A2
#define LCD_DB5 PIN_A3
#define LCD_DB6 PIN_A4
#define LCD_DB7 PIN_A5
#include "LCD.c"
//#include "flex_lcd.c"
//======================= Main ==============================
void main(void)
{
setup_adc_ports(NO_ANALOGS);
#define BEEP PIN_C0
#define RELAY PIN_C1
#define XMTHEN PIN_C5
output_low(BEEP);
output_low(RELAY);
output_low(XMTHEN);//turn off the TX_enable
//make sure we start with relays not activated
//===================== STARTUP SCREEN=====================//
fprintf(DEBUG,"Starting\n\r");
lcd_init();
while(1)
{
lcd_putc("\fHello There");
//fprintf(DEBUG,".");
}
}
|
..update ..
Tried a 16F877 and it works,.. but not 16F887 |
|
 |
PCM programmer
Joined: 06 Sep 2003
Posts: 21708
|
|
| Posted: Wed Jun 10, 2009 5:32 pm |
|
|
| Quote: | | CCS Ver 3.249 18F452/16F887 |
I just installed vs. 3.249 and I can't find the 16F88x files in it.
Did you add the 16F887 by yourself, using the Device Editor ? |
|
|
treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
|
|
| Posted: Thu Jun 11, 2009 7:56 am |
|
|
Yes. I used the 16F877A as starting point.. both have 8K words for programming and 256 data eeprom and portA at 5 and trisa at 0x85.
I'll try it again,... I seem to remember guessing at how to do something or another. I'm sure re-doing it will refresh my memory. |
|
|
treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
|
|
| Posted: Thu Jun 11, 2009 12:29 pm |
|
|
..update.. still can't fix it.
would a 16F877a hex programed onto the 887 work? at least for port A? |
|
|
PCM programmer
Joined: 06 Sep 2003
Posts: 21708
|
|
| Posted: Thu Jun 11, 2009 1:07 pm |
|
|
Part of the problem is likely the ANSEL and ANSELH registers in the
16F887. They power-up as all 1's, which sets much of Port A and Port B
as analog pins. If you just defined those register addresses with #byte
statements and then set both registers to 0x00 at the start of main(),
it might cure your problems.
| Quote: | | setup_adc_ports(NO_ANALOGS); |
Because you created the 16F887 with the Device Editor, there's no
guarantee that this line is writing to the correct registers. I would
delete this line and do it manually, as I suggested above.
Be aware that many of the built-in functions may not work correctly
with your created version of the 16F887. |
|
|
treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
|
|
| Posted: Thu Jun 11, 2009 1:31 pm |
|
|
| Got it working. Thanks! |
|
|
|
FAQ 
Search
Register
Profile 
Log in to check your private messages 
Log in
