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Message |
enyman
Joined: 09 Feb 2012
Posts: 8
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| pic 16F1937 capacitive pad |
 Posted: Fri Mar 09, 2012 6:52 pm |
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hi,
I'm using pic 16f1937 with a touchpad and I'm trying to make a LED (vorbiti) to light while I'm with the finger on the button and it's not working.
| Code: |
#include <16f1937.h>
#use delay(clock=500KHz)
#use touchpad (RANGE=L,THRESHOLD=6,SCANTIME=32,PIN_A5 ='1',pin_a4='2',pin_d0='3',pin_b0='4')
#define vorbiti pin_c4
#define acces pin_c2
#define mute pin_a3
#define vol_H pin_a0
#define vol_M pin_b7
#define vol_L pin_b6
void main()
{
TOUCHPAD_STATE(1);
enable_interrupts(GLOBAL);
char c;
int volum;
volum=3;
while (TRUE)
{
c='X';
if (touchpad_hit())
c=TOUCHPAD_GETC();
switch(c) {
case '1': switch(volum)
{
case 3: output_low(vol_H);volum=2;break;
case 2: output_low(vol_M);volum=1;break;
case 1: output_low(vol_L);output_high(mute);volum=0;break;
} break;
case '2': switch (volum)
{
case 0: output_low(mute);output_high(vol_L);volum=1;break;
case 1: output_high(vol_M);volum=2;break;
case 2: output_high(vol_H);volum=3;break;
} break;
case '3': access();break;
case '4':
while(c=='4')
{
output_high(vorbiti);
delay_ms(100);
c='Y';
if(touchpad_hit())
c=TOUCHPAD_GETC();
}output_low(vorbiti);
}
}
}
|
With pushbutton it's simple :
| Code: |
while(input(PIN_X))
{
output_high(PIN_Y);
}
|
But with touchpad it's not working.
I am using PCWHD 4.126.
Please help.
Thank you. |
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 |
enyman
Joined: 09 Feb 2012
Posts: 8
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| Posted: Wed Mar 14, 2012 7:58 am |
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| can someone help me ? please ? |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Mar 14, 2012 1:19 pm |
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1. Post your #fuses line. You need one.
2. Your code doesn't compile. It gives an Undefined identifier error for:
3. You are declaring variables in the middle of code:
| Quote: |
void main()
{
TOUCHPAD_STATE(1);
enable_interrupts(GLOBAL);
char c;
int volum;
volum=3;
|
This is not supported by CCS. It can produce strange bugs if you do it.
Variables must be declared at the start of a function. This includes main().
4. Pins B6 and B7 are used by the ICD programmer/debugger to talk to
the PIC. Choose some other pins for your project.
| Quote: | #define vorbiti pin_c4
#define acces pin_c2
#define mute pin_a3
#define vol_H pin_a0
#define vol_M pin_b7
#define vol_L pin_b6 |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Wed Mar 14, 2012 2:23 pm |
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A few more remarks:
5) | Code: | | #use delay(clock=500KHz) |
Is your CPU really running a 500kHz clock speed? It is very slow and not a standard crystal frequency.
6) The C programming language gives you a lot of freedom when it comes to the layout of your program, but freedom comes with responsibilities.
A) Your code has very wild indentation, sometimes lines are starting at the first column and then without reason jumping to the middle of the page. Your code will be easier to read when you only add an extra level of indentation after every '{' character.
B) The original C language is case sensitive, meaning that a command or variable is only understood when spelled exactly the same in the whole program. The CCS compiler is easier on this rule, unless you specify the #case directive. For easier reading of your program I recommend you to be consequent and stick to the original C rule. Write the function names in lower capitals as specified in the CCS manual (touchpad_getc, touchpad_hit), write constants and defines in full capitals (PIN_A4, PIN_D0, VOL_H, VOL_M, VORBITI, MUTE, etc.).
C) Only one command at a line! The compiler doesn't complain, but it makes reading a program so much more difficult.
| Code: | Not recommended:
case 0: output_low(mute);output_high(vol_L);volum=1;break;
case 1: output_high(vol_M);volum=2;break;
Suggestion:
case 0:
output_low(mute);
output_high(vol_L);
volum=1;
break;
case 1:
output_high(vol_M);
volum=2;
break; |
D) When using an if-statement where you put the corresponding command at the next line, at least add an extra level of indentation to make clear the command belongs to the if-statement. | Code: | wrong:
if(touchpad_hit())
c=TOUCHPAD_GETC();
Good:
if(touchpad_hit())
c=TOUCHPAD_GETC();
Best:
if(touchpad_hit())
{
c=TOUCHPAD_GETC();
} |
7) | Code: | c='X';
if (touchpad_hit())
c=TOUCHPAD_GETC();
switch(c) { |
An unusual code construct. First I thought you made a mistake, but the construct is there in your code two times. As you are not doing anything with the value 'X' inside the switch statement this means you are wasting processing power on running the switch statement when you know beforehand that this is unnecessary. Suggestion: read up on the 'else' command in the if-statement. |
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enyman
Joined: 09 Feb 2012
Posts: 8
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| Posted: Mon Mar 19, 2012 8:30 am |
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Thank you very much for reply.
I corrected the mistakes listed by you.
The access() procedure i forgot to write in the code above but.
| Code: |
void access()
{
output_high(acces);
delay_ms(2000);
output_low(acces)
}
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I have some fuses set in the .h file.
BUT I have the same problem, the led doesn't stay ON while I'm with the finger on the capacitive button! Why ? How can I do that ?
Thank you very much. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Mar 19, 2012 3:14 pm |
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I tested the program shown below with vs. 4.126 and it does sort of work.
I don't have the best touchpad. I used this one from Twin Industries:
http://twinind.com/catalog_detail.php?id=236
I just used the touchpad board on the left side of the photo, and cable.
The pads are smaller than normal, and split into two pieces, which is
not desirable. The "common" side pad is not used, only the other half
of each pad is used. My PIC board is the PicDem2-Plus (non-Rohs vs.).
I couldn't find a cheap stand-alone touchpad board with full size pads
for development purposes. I was looking for something like the Sparkfun
keypad board, except without any IC's on it. Just a bare board with each
pad going to a connector pin. http://www.sparkfun.com/products/10250
But I couldn't find one, so I used the Twin Industries board.
Here are my connections:
Pad 1 --> pin D4
Pad 2 --> pin D5
That's all. It doesn't work if you connect the common pin on the touchpad
to ground on the PIC board. (That's expected. Microchip says only
the pads should go to the PIC pins. No other connections).
Anyway, the code below will turn on the LED if I tap Pad 1 quickly.
If I then tap Pad 2 quickly, it will usually turn off the LED. Sometimes
it takes two taps to turn it off. I put Scotch tape over the pads because
a Touchpad is supposed to be insulated. I also turned the board upside
down and touched the pad locations on the back side. It also worked
that way, which is expected. The board is 1/16 inch (1.575 mm) thick
of FR4 printed circuit fiberglass material.
It seems to work a little bit better with a scantime of 64 ms compared
to 32 ms. The threshold is very important. I could only make it work
with a threshold of 6 or 7. Using a threshold 5 or 10 didn't work at all.
One of the most important things to make it work was to make sure
that the PIC pins are only connected to the Touchpad board. I had to
study the schematic of my PicDem2-Plus (non-Rohs vs.) to find some
pins that didn't have external circuits on them, and that also were CPS
pins on the 16F1937. On my board, pins D4 and D5 were free.
I want to make this very clear: You can't have any pull-up resistors
or other components or IC's on the touchpad pins.
I also tested it with vs. 4.130 and got the same results.
| Code: |
#include <16F1937.h>
#fuses INTRC_IO,NOWDT,BROWNOUT,PUT
#use delay(clock=4M)
#use touchpad(scantime=64ms, threshold=7, Range=H, PIN_D4='1', PIN_D5='2')
#define LED_PIN PIN_B0
//===========================
void main()
{
int8 c;
output_low(LED_PIN); // LED Off
enable_interrupts(GLOBAL); // Required by #use touchpad() documenation
while(1)
{
c = touchpad_getc(); // Wait for pad 1 or 2 to be touched
if(c == '1')
output_high(LED_PIN); // On
if(c == '2')
output_low(LED_PIN); // Off
delay_ms(10);
}
} |
The 10ms delay is in there just because I was playing around with
methods to make it detect the touches (finger taps on the pads) more
reliably. I think the delay helps a little. |
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octopuss83
Joined: 06 Nov 2011
Posts: 13
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| Same problem |
| Posted: Thu Mar 22, 2012 1:23 am |
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I have the same problem as you, CCS routines are not adapted to the detection of the moment or the key is down. For me I opted for the rewrite of a routine in accordance with the application note AN1103 from Microchip.
You can find the code here:
http://ww1.microchip.com/downloads/en/AppNotes/AN1171_revB.zip
and the note here
http://www.microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1824&appnote=en534210
In my case I'm using the PIC16F1825. I had to modify the program especially at the records of micro registers:
| Code: |
#define L_Sound PIN_A1
#define L_Light PIN_A0
#define S_Touch PIN_C1
#define L_Touch PIN_C0
// Declarations registres
#byte ANSELC = 0x18E
#byte OPTION_REG = 0x95
#byte INTCON = 0x0B
#bit TMR0IF = INTCON.2
#bit TMR0IE = INTCON.5
#bit PEIE = INTCON.6
#bit GIE = INTCON.7
#byte T1CON = 0x18
#bit TMR1ON = T1CON.0
#byte TMR1L = 0x16
#byte TMR1H = 0x17
#byte T1GCON = 0x19
#byte CPSCON0 = 0x1E
#byte CPSCON1 = 0x1F
#bit CPSOUT = CPSCON0.1
#byte PIR1 = 0x11
#bit TMR1GIF = PIR1.7
#bit TMR2IF = PIR1.1
#byte PIE1 = 0x91
#bit TMR1GIE = PIE1.7
#bit TMR2IE = PIE1.1
// Definition des channel cap^sensor
#define CPS0 0
#define CPS1 1
#define CPS2 2
#define CPS3 3
#define CPS4 4
#define CPS5 5
#define CPS6 6
#define CPS7 7
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To date the program was not working but I'm working on it from time to time.
_________________
______________________
-- Octopuss --- |
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octopuss83
Joined: 06 Nov 2011
Posts: 13
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octopuss83
Joined: 06 Nov 2011
Posts: 13
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| capacitive pad |
| Posted: Sat Mar 24, 2012 4:27 am |
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Now it works, I've corrected option_reg error in an1171.
Contact me if you want source code.
_________________
______________________
-- Octopuss --- |
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JORATORCA
Joined: 30 May 2012
Posts: 1
Location: VALENCIA (SPAIN)
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| Posted: Wed May 30, 2012 3:10 pm |
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Octopuss,
I have some time working on a code for a capacitive button with the 12F1822. The code was originally developed for the 16F727 and worked well. In trying to adapt the configuration to the 12F1822 can not get it to work. The PIC is of the same family as the 16F1825 that you have used. I think your code could guide me on what I'm doing wrong. Could you give me your code?. |
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octopuss83
Joined: 06 Nov 2011
Posts: 13
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| Posted: Thu May 31, 2012 11:14 am |
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Ok, can I have your mail, I can send to you .C .h Files.
_________________
______________________
-- Octopuss --- |
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