PIC16F886 (and 18F2620) with TSMP4138 and NEC code

[pekka1234]

I have tried to get NEC IR code with four different IR transmitters.
Samsung, Thso.E10imi. Grundic and Terratec for normal TV transmitters

The IR receiver is TSM4138, which reads all the transmitters.
The code comes with scope just fine with NEC code, it went to
#INT_EXT (RB0).


I have used to count interrupts, but I can't see nothing with serial outputs. Low signal 0.65 ms and high 1.65ms.
Some transmitters has also startting signals.
I have used 115200 baud for serial baud.

This is my Interrupt code
#include <16F886.h>
#device ADC=10
#fuses INTRC_IO, NOWDT, NOPROTECT, NOLVP, NOMCLR
#use delay(clock=8000000)
#use rs232(baud=115200, parity=N, xmit=PIN_C6, rcv=PIN_C7, bits=8, invert)
#define REDLED PIN_C4
volatile int8 bit_count;
volatile int1 state;
volatile unsigned long ir_code = 0;
volatile int1 decoding = 0;
int16 low=0;
int16 High=0;
#INT_EXT
void ir_isr() {

if(bit_count == 32) {
for(int i = 0; i < 10; i++) { //Blick fast RED led
output_toggle (REDLED); //
delay_ms(100);
}
ir_ready = 1;
}



// Logic 0 ~1.1 ms
if(timer_value > 900 && timer_value < 1400) {
// bit = 0
}
// Logic 1 ~2.25 ms
else if(timer_value > 2000 && timer_value < 2600) {
ir_code |= (1UL << bit_count);
}
else {
state = 0; // error or repeat
return;
}

bit_count++;

if(bit_count == 32) {
ir_ready = 1;
state = 0;
}
}

And this is my main code
void main ()
{

set_tris_b(0x41);
set_tris_a(0b00010001);
set_tris_b(0b01000001);
set_tris_c(0b00010001);
enable_interrupts(INT_EXT);
enable_interrupts(GLOBAL);
while(1)
{
printf(("low %ld high %ld\r", low, high);
delay_ms(5000);
low =0;
high=0;
}
}

Please can you help.
It is remote control for tube inside 360 degrees measurements for every 50 mm inside the metal 100mm tube with two step motors. It done for automatic movement. The measurement is done with a laser signal.

Pekka

[temtronic]

general comments....
1 it's a really bad idea to have ANY delays inside any ISR. You have a delay_ms(100) which is real bad.....

2) variable 'timer_value' ?? Doesn't seem to be defined though I suspect it's a register for a timer ?
if true ,then there's no setup shown for the timer.

I'm sure others will respond soon.

[Ttelmah]

Also as posted, the timer is not being reset anywhere. So the timer_value
will effectively be a semi random value, based on when the interrupt
happens versus the free running timer. Not going to give a sensible result.
My guess is the code should have the timer being reset.
I'm guessing also that the original code was using an interrupt on change,
not a single edge interrupt (which INT_EXT is), so could reset the timer on
one edge, and then check the count on the other to know the pulse width.
INT_EXT cannot do this. It triggers on one signal edge only. High to low or
low to high, which can be setup in it's configuration.

[pekka1234]

Thank you for all.
I know that it was quite difficult to help, but I have tried to do the small code few days.

Anyway, I got it working
I use IR NEC code, but it was still a lot of work.
I used a Samsung transmitter and TSMP4i38 (old) IR receiver.

This is a stepper motor speed control. It also sends back a laser signal.
It moves inside the metal tube and measures the inside diameter.
The other motor moves a laser over 360 degrees