Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

Battery Charger - Led Blink Problem

Status
Not open for further replies.
O

Okada

Banned
Advanced Member level 4
Joined
Jun 16, 2016
Messages
1,159
Helped
129
Reputation
252
Reaction score
129
Trophy points
63
Activity points
0
Hi

I am making a simple Battery Charger using PIC12F675. All registers are configured properly. I have used mikroE Timer Calculator to generate 250 ms Timer1 interrupt code. I need to blink the green Led three times at 500 ms when the device starts but it is only blinking once. I don't know what is the problem. I spent 4 hours trying to figure out the problem but not able to find it.

I am attaching mikroC PRO PIC project and Proteus file.

The code inside the timer routine in ISR has two nested if() conditions and if I comment the inner if() condition then Green Led blinks at 500ms continuously.
 

Attachments

  • 12V Battery Charger.rar
    28.1 KB · Views: 125

Here is the code.

Code C - [expand]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75

#define ON  1
#define OFF 0
 
sbit Relay at GP1_bit;
sbit Mosfet at GP2_bit;
sbit Charged_Led at GP4_bit;
sbit Charging_led at GP5_bit;
 
unsigned char my_flags = 0;
unsigned char state_counter = 0, led_blink_counter = 0, led_blink_count = 2, led_blink_delay_counter = 0, led_blink_delay_count = 3;
double mains_voltage = 0.0, previous_mains_voltage = 0.0;
 
sbit control_relay_and_mosfet_flag at my_flags.B0;
 
//Timer1
//Prescaler 1:4; TMR1 Preload = 3036; Actual Interrupt Time : 250 ms
//Place/Copy this part in declaration section
void InitTimer1() {
    T1CON = 0x21;
    TMR1IF_bit = 0;
    TMR1H = 0x0B;
    TMR1L = 0xDC;
    TMR1IE_bit = 1;
    INTCON = 0xC0;
}
 
void Interrupt() {
    if((TMR1IE_bit) && (TMR1IF_bit)) {
      //Enter your code here
      if(state_counter == 0) {
         if(++led_blink_counter == led_blink_count) {
             Charging_Led = ~Charging_Led;
             led_blink_counter = 0;
 
             if(++led_blink_delay_counter == led_blink_delay_count) {
                  state_counter = 1;
                  led_blink_delay_counter = 0;
                  TMR1IE_bit = 0;
                  control_relay_and_mosfet_flag = 1;
             }
         }
      }
      
      TMR1IF_bit = 0;
      TMR1H = 0x0B;
      TMR1L = 0xDC;
    }
}
 
void main() {
 
    asm clrwdt
    OPTION_REG = 0x8F;
 
    CMCON = 0x07;
 
    ANSEL = 0x51;
    ADCON0 = 0x80;
 
    TRISIO = 0x01;
    GPIO = 0x00;
 
    Delay_ms(100);
 
    state_counter = 0;
    control_relay_and_mosfet_flag = 0;
 
    InitTimer1();
 
    while(1) {
 
          asm clrwdt
 
    }
}
 

What for you checking this flag?
Code: 
if(([COLOR="#FF0000"][B]TMR1IE_bit[/B][/COLOR]) && (TMR1IF_bit))
 

TMR1IE_bit is Timer1 Interrupt Enable bit and TMR1IF_bit is Timer1 Interrupt flag bit.

In the code if below if() condition is commented

Code: 
if(++led_blink_delay_counter == led_blink_delay_count) {

}

then Charging_Led (Green Led) blinks at 500 ms interval continuously which is correct but if the above if() condition is uncommented then it has to stop after blinking 3 times but it is stopping after blinking 1 time.
 

TMR1IE_bit, once cleared in the ISR, is not set again which bars the ISR to act endlessly.

Code: 
#define ON  1
#define OFF 0

sbit Relay at GP1_bit;
sbit Mosfet at GP2_bit;
sbit Charged_Led at GP4_bit;
sbit Charging_led at GP5_bit;

unsigned char my_flags = 0;
unsigned char state_counter = 0, led_blink_counter = 0, led_blink_count = 2, led_blink_delay_counter = 0, led_blink_delay_count = 3;
double mains_voltage = 0.0, previous_mains_voltage = 0.0;

sbit control_relay_and_mosfet_flag at my_flags.B0;

//Timer1
//Prescaler 1:4; TMR1 Preload = 3036; Actual Interrupt Time : 250 ms
//Place/Copy this part in declaration section
void InitTimer1() {
    T1CON = 0x21;
    TMR1IF_bit = 0;
    TMR1H = 0x0B;
    TMR1L = 0xDC;
    TMR1IE_bit = 1;
    INTCON = 0xC0;
}

void Interrupt() {
    if(([COLOR="#FF0000"]TMR1IE_bit[/COLOR]) && (TMR1IF_bit)) {
      //Enter your code here
      if(state_counter == 0) {
         if(++led_blink_counter == led_blink_count) {
             Charging_Led = ~Charging_Led;
             led_blink_counter = 0;

             if(++led_blink_delay_counter == led_blink_delay_count) {
                  state_counter = 1;
                  led_blink_delay_counter = 0;
                  [COLOR="#FF0000"]TMR1IE_bit = 0;[/COLOR]
                  control_relay_and_mosfet_flag = 1;
             }
         }
      }
      
      TMR1IF_bit = 0;
      TMR1H = 0x0B;
      TMR1L = 0xDC;
    }
}

void main() {

    asm clrwdt
    OPTION_REG = 0x8F;

    CMCON = 0x07;

    ANSEL = 0x51;
    ADCON0 = 0x80;

    TRISIO = 0x01;
    GPIO = 0x00;

    Delay_ms(100);

    state_counter = 0;
    control_relay_and_mosfet_flag = 0;

    InitTimer1();

    while(1) {

          asm clrwdt

    }
}
 

As I understood from the code, led_blink_delay_counter reaches led_blink_delay_count value after 3 led toggles (0->1->0->1), but not after 3 blinks, which is in fact 6 toggles.
Try to increase led_blink_delay_count.
 
  • Like
Reactions: Okada

    O

    Okada

    Points: 2
    Helpful Answer Positive Rating
Timer interrupt is for 250 ms

Code: 
if(++led_blink_counter == led_blink_count) {

makes Charging_Led to blink at 500 ms Interval

This

Code: 
if(++led_blink_delay_counter == led_blink_delay_count) {

condition is executed when after 3x 500ms interrupts and so it has to stop at count 3.


Altaero is right. I have to increase the count from 3 to 6. It works now. Thanks Altaero.
 
Last edited:

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top