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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Problems reading PORTB inputs |
 Posted: Wed Nov 10, 2004 11:42 am |
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Connected to RB6 and RB7 are Normally Closed (NC) switches. So normally, RB6 and RB7 should be reading GND, and when the switches are set both should be reading +5V. However, when we read the PORTB register, setting the switch on RB7 actually sets bit 6 of register PORTB instead of bit 7, and setting the switch on RB6 does nothing. What is going on? Here is our complete program. It is actually five separate files but I've put them into one file so I could post it... I have comments where each file ends and begins.
We are using PIC16F627A
Our compiler is the PCW Compiler, IDE version 3.30, PCB version 3.155, PCM version 3.155, and PCH version 3.155
| Code: |
/*************************************************/
// THIS IS A SEPARATE FILE - AUTOSENSOR.H
#include <16F627A.h>
#use delay(clock=4000000)
#fuses INTRC_IO,NOWDT
/************ END AUTOSENSOR.H **************/
/**************************************************/
// THIS IS A SEPARATE FILE - PROJECT_DEFS.H
// Buttons --- BT = Button
#define BT_RET_Pushed !input(PIN_A0)
#define BT_RET_NOT_Pushed input(PIN_A0)
#define BT_EL_Pushed !input(PIN_A4)
#define BT_EL_NOT_Pushed input(PIN_A4)
#define BT_TURN_Pushed !input(PIN_B1)
#define BT_TURN_NOT_Pushed input(PIN_B1)
#define BT_POWER_Pushed !input(PIN_B0)
#define BT_POWER_NOT_Pushed input(PIN_B0)
//LEDs
#define Motion_LED_On output_high(PIN_A7)
#define Motion_LED_Off output_low(PIN_A7)
#define Raised_LED_On output_high(PIN_A3)
#define Raised_LED_Off output_low(PIN_A3)
#define Travel_LED_On output_high(PIN_B2)
#define Travel_LED_Off output_low(PIN_B2)
//Limit Switches --- LS = Limit Switch
#define Down_LS_SET input(PIN_B3)
//#define Down_LS_NOTSET !input(PIN_B3)
#define END_LS_SET input(PIN_B6)
//#define END_LS_NOTSET !input(PIN_B6)
#define START_LS_SET input(PIN_B7)
//#define START_LS_NOTSET !input(PIN_B7)
//Motor Controls
#define Enable_On output_high(PIN_A6)
#define Enable_Off output_low(PIN_A6)
#define Phase_On output_high (PIN_B5)
#define Phase_Off output_low (PIN_B5)
//Puts entire system to sleep
#define Sleep_Off output_high (PIN_B4)
#define Sleep_On output_low (PIN_B4)
/************ END PROJECT_DEFS.H **************/
/****************************************************/
// THIS IS A SEPARATE FILE - DEBOUNCE.C
void debounce(void)
{
delay_ms(250);
while(BT_POWER_Pushed || BT_EL_Pushed)
delay_ms(20);
}
/************ END DEBOUNCE.C **************/
/****************************************************/
// THIS IS A SEPARATE FILE - MOTOR.C
/******* Motor Truth Table ***********
Phase Enable Sleep Function
----- ------ ----- --------
1 1 1 Forward
0 1 1 Reverse
X 0 1 Brake
X X 0 Sleep Mode
*****************************************/
void motor_CCW(void)
{
Motion_LED_On;
Phase_On;
Enable_On;
}
void motor_CW(void)
{
Motion_LED_On;
Phase_Off;
Enable_On;
}
void motor_STOP(void)
{
Motion_LED_Off;
Enable_Off;
}
/************ END MOTOR.C **************/
/*************************************************************
MAIN PROGRAM
*************************************************************/
#include "AutoSensor.h"
#include "project_defs.h"
#include "debounce.c"
#include "motor.c"
#ZERO_RAM
boolean POWER_ON = FALSE; //Power button
/************************************************************
Interrupt Function
************************************************************/
#int_EXT
EXT_isr() {
debounce();
if(POWER_ON)
POWER_ON = FALSE;
else
POWER_ON = TRUE;
if (POWER_ON) //Power On
Sleep_Off;
else
Sleep_On; //Puts everything to sleep
}
/************************************************************
Main Function
************************************************************/
void main() {
Sleep_On;
port_b_pullups(TRUE);
setup_counters(RTCC_INTERNAL,WDT_2304MS);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_comparator(NC_NC_A1_A2);
setup_vref(FALSE);
enable_interrupts(global);
enable_interrupts(INT_EXT);
while(TRUE){
while (POWER_ON)
{
// if neither button is pushed, Brake
if (BT_TURN_NOT_Pushed && BT_RET_NOT_Pushed)
motor_STOP();
// if Turn is pushed, rotate counterclockwise
while (BT_TURN_Pushed)
{
if (END_LS_SET)
motor_STOP();
else
motor_CCW();
}
// if RETURN is pushed, rotate clockwise
while (BT_RET_Pushed)
{
if (START_LS_SET)
{
motor_STOP();
Raised_LED_On;
}
else
motor_CW();
}
}
/***********************************************************
Sleep Mode
setting PIN_A2 high gives lowest sleep current
***********************************************************/
setup_comparator(NC_NC_NC_NC); // disable comparator
output_high (PIN_A2);
#ASM
SLEEP
NOP
#ENDASM
output_low (PIN_A2);
setup_comparator(NC_NC_A1_A2);
}
}
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Wed Nov 10, 2004 12:47 pm |
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| Quote: |
#fuses INTRC_IO,NOWDT
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change to:
#fuses INTRC_IO,NOWDT,NOLVP,NOPROTECT
Humberto |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Wed Nov 10, 2004 12:51 pm |
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| Are you using an ICD to read PORTB? |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Wed Nov 10, 2004 12:55 pm |
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that wasn't it. But thanx anyway Humberto
Last edited by Sensor on Wed Nov 10, 2004 1:01 pm; edited 1 time in total |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Wed Nov 10, 2004 1:00 pm |
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To Marks question....
We are using the MPLAB ICE 2000, with MPLAB version 6.60. We are reading the register PORTB under special function registers in MPLAB v6.60. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Wed Nov 10, 2004 1:03 pm |
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| I would check the hardware. |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Wed Nov 10, 2004 1:07 pm |
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We think we exausted that possibility but we can do that again. The last physical connection (RB7) going into the emulator will behave as expected. i.e it WILL go high when we set the switch, but the PORTB register does not correspond to that, namely it registers it as a RB6 change.
Also the Input change on RB6 does register on the last physical connection to the emulator, but when we read the PORTB register, no changes are registered. |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Wed Nov 10, 2004 1:10 pm |
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| Have you tried a real chip? Its possible that the emulator pod is bad. |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Wed Nov 10, 2004 1:14 pm |
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We have not tried a real chip yet. However I want to mention this though:
If we do a simple command | Code: | | output_high(PIN_B7); |
we DO see a change in the register, namely it does go high on RB7 |
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Mark
Joined: 07 Sep 2003
Posts: 2838
Location: Atlanta, GA
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| Posted: Wed Nov 10, 2004 1:16 pm |
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| The input buffers are different from the outputs. You can blow em up (inputs) and the outputs still work okay. |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Wed Nov 10, 2004 1:19 pm |
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| is there any way to verify that |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Wed Nov 10, 2004 2:24 pm |
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IMO you must reduce your code to minimum, at least to the level were you
feel confidence with the hardware, software and tools you are using.
Just an input switch and an output LED.
| Code: |
while(TRUE)
{
if (END_LS_SET)
Led_OFF;
else
Led_ON;
}
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Then and only when the hardware does what you coded, you have a real case to post
the results or behaviour, meanwhile you are playing with "virtual" inputs and outputs.
HTH,
Humberto  |
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Sensor
Joined: 04 Nov 2004
Posts: 33
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| Posted: Mon Nov 15, 2004 10:54 am |
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@ Mark
and everybody else...
Thanx. It turns out that our emulation kit is defective. We did sucessfully program the real chip and it is behaving as expected.
Thanx again for all of your help |
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