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jspencer
Joined: 22 Dec 2003
Posts: 57
Location: Boise, ID USA
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| drawing 2mA doing nothing |
 Posted: Tue Feb 14, 2006 3:32 pm |
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I'm using a 16F688 part and am having some issues getting the power consumption down when it is running, but not necessarily doing anything. I have a 10 sec delay and during that time it is drawing 2mA. The wierd thing is, that I have some chips that I programmed a couple of weeks ago (exact same hardware slightly different code) that are drawing a few hundred uA. I did a diff on the two versions and didn't see anything that should cause the change in current.
I am using a 32kHz crystal for Timer1 and 500kHz internal oscillator. I've shut everything off that I am not using and looked over the fuses a number of times with no luck seeing what I am doing wrong.
Any extra set of eyes would be helpful.
Thanks,
jspencer
| Code: |
#include <16F688.h>
#use delay(clock=500000)
// Will need to change to code protect
#fuses INTRC_IO
#fuses NOWDT
#fuses PROTECT
//#fuses NOPROTECT
#fuses NOMCLR
#fuses NOCPD
#fuses NOBROWNOUT
#fuses PUT
#fuses NOIESO
#fuses NOFCMEN
// External interrupt routine. PIN_A2 is the I/O line and is used for
// activation of the device
#int_EXT
EXT_isr() {
z = 0;
// This is bad and will need to be changed, but functional for now.
for (y=0;y<50;y++) {
if (input(PIN_A2)) {
z++;
if (z > 20) {
activated_flag = TRUE;
break;
}
delay_ms(5);
}
}
}
// Timer1 interrupt routine. Used for sleeping X amount of time and for
// counting how much time has elapsed while processing.
#int_TIMER1
TIMER1_isr() {
}
void main() {
init_routine();
// do rest of program.
}
void init_routine() {
int i_cnt;
// initialization of features
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_EXTERNAL|T1_DIV_BY_8|T1_CLK_OUT);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
setup_wdt(WDT_OFF);
setup_adc(ADC_OFF);
setup_adc_ports(NO_ANALOGS);
setup_oscillator(OSC_500KHZ);
port_a_pullups(FALSE);
//setup_low_volt_detect(FALSE);
init_ext_eeprom();
TCN75_init();
setup_one_shot();
enable_interrupts(INT_TIMER1);
enable_interrupts(INT_EXT);
enable_interrupts(global);
// Sets up INT_EXT to watch for the rising edge
ext_int_edge(L_TO_H);
SET_TRIS_A(0x04);
// A0 OUTPUT
// A1 OUTPUT
// A2 INPUT
// A3 OUTPUT
// A4 OUTPUT
// A5 OUTPUT
SET_TRIS_C(0x00);
// C0 OUTPUT
// C1 OUTPUT
// C2 OUTPUT
// C3 OUTPUT
// C4 OUTPUT
// C5 OUTPUT
// initial flashing sequence
for (i_cnt=0; i_cnt<2; i_cnt++) {
flash(0x04, 5);
delay_ms(150);
flash(0x02, 5);
delay_ms(150);
flash(0x01, 5);
delay_ms(150);
}
// reading 2mA during this delay.
delay_ms(10000);
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Tue Feb 14, 2006 3:51 pm |
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1. Is this for the PIC only, or the entire board ?
2. Is there a voltage regulator ? If so, what is the part number ?
3. Are all i/o pins set to a state such that no power will be drawn
by external circuits ? i.e., if you have a pull-up resistor on
a pin, set the pin to be an input, or a high-level output.
Don't set it to be a low-level output.
4. You've got a flashing routine in there. I would remove that
code for this test. Who knows what state those pins are left in ?
5. You're ending the code with a 10 second delay. As soon as the
delay ends, the PIC will execute a hidden SLEEP instruction
(put there by the compiler) and go to sleep.
I think you should either explicitly test it in sleep mode, or
test it in non-sleep mode. The test should not have a temporary
delay.
Either put this at the end of main():
or this:
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jspencer
Joined: 22 Dec 2003
Posts: 57
Location: Boise, ID USA
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| Posted: Tue Feb 14, 2006 4:09 pm |
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I only cut and pasted part of the code, so there is quite a bit that is not shown.
| Quote: |
1. Is this for the PIC only, or the entire board ?
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It is for the entire board, but the other components when not in use are only drawing 6-7 uA and when in use it is really low.
| Quote: |
2. Is there a voltage regulator ? If so, what is the part number ?
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There is no regulator, we are using a 3V coin cell.
| Quote: |
3. Are all i/o pins set to a state such that no power will be drawn
by external circuits ? i.e., if you have a pull-up resistor on
a pin, set the pin to be an input, or a high-level output.
Don't set it to be a low-level output.
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Only have one pull-up and it is a input.
| Quote: |
4. You've got a flashing routine in there. I would remove that
code for this test. Who knows what state those pins are left in ?
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The flashing routine always leaves the output pins in a low state, but this maybe where my problem is, as i have leds on 3 output pins on the port, but I just noticed that I am doing this: ouput_c(0x07) to flash all leds on the port, but it is also setting the other port pins to a low state.
| Quote: |
5. You're ending the code with a 10 second delay. As soon as the
delay ends, the PIC will execute a hidden SLEEP instruction
(put there by the compiler) and go to sleep.
I think you should either explicitly test it in sleep mode, or
test it in non-sleep mode. The test should not have a temporary
delay.
Either put this at the end of main():
or this:
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Again, just didn't paste all of the code, my bad. I do have a never ending while loop in main. In sleep mode I am drawing between 10 and 20 uA which is where I need to be.
I'll try the output thing, as that is one thing that I did change between revisions. I'm pretty sure that this is the problem.
Thanks for the extra eyes!
jspencer |
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jspencer
Joined: 22 Dec 2003
Posts: 57
Location: Boise, ID USA
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| Posted: Tue Feb 14, 2006 5:42 pm |
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Well, I've reduced it to this.
| Code: |
#include <16F688.h>
#use delay(clock=500000)
// Will need to change to code protect
#fuses INTRC_IO
#fuses NOWDT
#fuses PROTECT
//#fuses NOPROTECT
#fuses NOMCLR
#fuses NOCPD
#fuses NOBROWNOUT
#fuses PUT
#fuses NOIESO
#fuses NOFCMEN
//********************************************************************
// VARIABLE DECLARATIONS/INITIALIZATION
//********************************************************************
// loop counter variable
int i, x, y, z;
short ut1_flag = FALSE;
short ot1_flag = FALSE;
short b4_alert_flag = FALSE;
short memory_full_flag = FALSE;
short activated_flag = FALSE;
short tti_flag = FALSE;
//********************************************************************
// INTERRUPT SERVICE ROUTINES
//********************************************************************
// External interrupt routine. PIN_A2 is the I/O line and is used for
// activation of the device
#int_EXT
EXT_isr() {
z = 0;
for (y=0;y<50;y++) {
if (input(PIN_A2)) {
z++;
if (z > 20) {
activated_flag = TRUE;
break;
}
delay_ms(5);
}
}
}
// Timer1 interrupt routine. Used for sleeping X amount of time and for
// counting how much time has elapsed while processing.
#int_TIMER1
TIMER1_isr() {
}
//********************************************************************
// Function that initializes the PIC and takes care of all the house
// keeping and setup
// Parameters: 0
// @ returns - nothing
//********************************************************************
void init_routine() {
int i_cnt;
// initialization of features
//setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_EXTERNAL|T1_DIV_BY_8|T1_CLK_OUT);
setup_comparator(NC_NC_NC_NC);
setup_vref(FALSE);
setup_wdt(WDT_OFF);
setup_adc(ADC_OFF);
setup_adc_ports(NO_ANALOGS);
setup_oscillator(OSC_500KHZ);
port_a_pullups(FALSE);
//SET_TRIS_A(0x04);
//SET_TRIS_C(0x00);
enable_interrupts(INT_TIMER1);
enable_interrupts(INT_EXT);
enable_interrupts(global);
// Sets up INT_EXT to watch for the rising edge
ext_int_edge(L_TO_H);
}
//********************************************************************
// Main function
//********************************************************************
void main() {
// initialization of all the PIC features that are needed
init_routine();
while (1) {
output_high(PIN_C0);
delay_ms(200);
output_low(PIN_C0);
delay_ms(3000);
}
}
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Now this will work and draw only 200uA, but if I uncomment the SET_TRIS_A(0x04) and the SET_TRIS_C(0x00) statements the circuit draws 2mA.
EDIT***
There is something flaky going on as now it will work just fine. Getting stumped as to the issue.
***
Thanks,
jspencer |
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jspencer
Joined: 22 Dec 2003
Posts: 57
Location: Boise, ID USA
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| Posted: Wed Feb 15, 2006 3:56 pm |
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| Well, it was the output_c() call that I was making. The I2C lines are also on that port and I don't think it liked that much. |
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