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ICM7218AIJI CCS C Driver Required

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Nisar

Joined: 16 Nov 2007
Posts: 20

ICM7218AIJI CCS C Driver Required
Posted: Sat Aug 22, 2009 5:36 am

Hi all I want to drive 8 common anode seven segment display with ICM7218AIJI. I have to under stand problem ICM7218 Data sheet. Plz any one hint me how I write its CCS C program to run displays. Regards Nisar

PCM programmer

Joined: 06 Sep 2003
Posts: 21708

Posted: Sun Aug 23, 2009 1:24 pm

Quote:

Plz any one hint me how I write its CCS C program to run displays.

The icm7218 has a parallel interface consisting of an 8 bit data bus and
two control signals. For the 8 data bits, you can use Port B. Then set
the data bits to a specified value with the output_b() function.

There are two control signals, Write and Mode. The Write signal idles
(i.e., the in-active state) at a high level, and the Mode signal idles at a
low level. You can use two i/o pins on the PIC for these signals, such as
pins C0 and C1. Then use output_low() and output_high() to control
these signals.

This page has a schematic of the connections (to a PC parallel port):
http://insentricity.com/?postid=57

This is the Linux used on the page above:
http://f2z.net/LED-Display/icm7218.c

This is the ICM7218 data sheet:
http://www.intersil.com/data/fn/FN3159.pdf

You can translate the Linux code to CCS. Look at the timing diagrams
on page 6 of the ICM7218 data sheet (Figures 4 and 5).

I'll go through his display_string() routine and make comments on what
you need to do to convert it to CCS. I'll put comments above each
section of code.

Quote:

void display_string(const char *str, int fd)
{
unsigned char status, control, data;
unsigned char mask;

The structure declaration below is not needed. It can all be done with the
output_b(), output_high() and output_low() functions.
struct ppdev_frob_struct frob;

char buf[DISPLAY_DIGITS + 1];
int i;

for (i = 0; i < DISPLAY_DIGITS; i++)
buf[i] = ' ';
strncpy(buf, str, DISPLAY_DIGITS);

Here, he is setting the Mode and Write signals to their idle states.
You can use output_low() for Mode and output_high() for Write, to do
this, instead of these 3 lines below.
/* Turn off write and mode, pins are inverted */
frob.mask = PARPORT_CONTROL_STROBE | PARPORT_CONTROL_SELECT;
frob.val = PARPORT_CONTROL_SELECT;
ioctl(fd, PPFCONTROL, &frob);

Here, he's setting the 8-bit data bus to a value consisting of two constants
that are bitwise OR'ed together. You can use output_b() to write 'data'
to the data bus of the ICM7218 instead of the ioctl() function.
data = ICM_NOTSHUTDOWN | ICM_HEXA;
ioctl(fd, PPWDATA, &data);

Here, he's apparently trying to initialize the chip by sending 9 sequential
write pulses to it. The write pulses are negative-going pulses. You
can use output_low() and output_high() inside the for() loop to do this.
This will replace all the other code inside the for() loop.

/* Try to get the chip into a known state */
for (i = 0; i < 9; i++) {
frob.mask = PARPORT_CONTROL_STROBE;
frob.val = PARPORT_CONTROL_STROBE;
ioctl(fd, PPFCONTROL, &frob);
frob.val = 0;
ioctl(fd, PPFCONTROL, &frob);
}

--------------------------------------------
This section between the dotted lines, is the same as the first part of
the timing diagram shown in Figure 5 of the ICM7218 data sheet.
It consists of
1. Write data to the data bus.
2. Set the Mode signal high.
3. Pulse the Write signal once (make a negative pulse).
4. Set the Mode signal low.

Here he's writing 'data' to the bus again. You can do it with output_b().
Again, this replaces the ioctl() function.
data = ICM_NOTSHUTDOWN | ICM_NOTDECODE | ICM_DATA;
ioctl(fd, PPWDATA, &data);

Set the Mode signal high. You can use output_high() to do this
instead of these lines below.
/* Start control mode */
frob.mask = PARPORT_CONTROL_SELECT;
frob.val = 0;
ioctl(fd, PPFCONTROL, &frob);

Set the Write signal low. You can use output_low() to do this
instead of these lines below.
/* Pulse write */
frob.mask = PARPORT_CONTROL_STROBE;
frob.val = PARPORT_CONTROL_STROBE;
ioctl(fd, PPFCONTROL, &frob);

Set the Write signal high. You can use output_high() for this
instead of these lines below.
/* End the pulse */
frob.val = 0;
ioctl(fd, PPFCONTROL, &frob);

Set the Mode signal low. You can use output_low() to do this
instead of these lines below.
/* End control mode */
frob.mask = PARPORT_CONTROL_SELECT;
frob.val = PARPORT_CONTROL_SELECT;
ioctl(fd, PPFCONTROL, &frob);

--------------------------------------------

This is the next part of Figure 5 in the ICM7218 data sheet, where it
shows 8 sequential Write pulses. He does this with a for() loop that
counts through 8 iterations.
for (i = 0; i < 8; i++) {
/* Data goes in reverse */
data = buf[7 - i];
data = 0x80 ^ ((data & 0x80) | (segments[data & 0x7f]));

Here, he is writing 'data' to the data bus. You can do this with output_b()
ioctl(fd, PPWDATA, &data);

In these next two sections, he is creating the negative-going write pulse.
You can do this with output_low() and output_high() to do this, instead
of these lines below.
/* Pulse write */
frob.mask = PARPORT_CONTROL_STROBE;
frob.val = PARPORT_CONTROL_STROBE;
ioctl(fd, PPFCONTROL, &frob);

/* End the pulse */
frob.val = 0;
ioctl(fd, PPFCONTROL, &frob);
}

This return statement is not needed because the function automatically
returns when it's done.
return;
}

Nisar

Joined: 16 Nov 2007
Posts: 20

ICM7218AIJI CCS C Driver Required
Posted: Mon Aug 24, 2009 1:58 am

Thanks

Nisar

Joined: 16 Nov 2007
Posts: 20

Posted: Mon Sep 28, 2009 5:00 am

Hello every one
I want to display 10 character numeric string from key board via serial port on common-anode 10 seven segments using ICM7218A driver. When I put 10 character numeric string, my code is ok, but my problem is that I want capture only 0 to 9 numeric keys. But when I Press "A" it sends 10 and when "B" sends 20 and so on, on seven segments. How can I capture 0 to 9 numeric characters only?
My code is:

Code:

/*Sending 10 character Serially Numeric Data on Common Anode Seven Segment Display
Using ICM7218A*/
#if defined(__PCM__)
#include <16F877A.h>
#fuses HS,NOWDT,NOPROTECT,NOPUT,NOLVP
#use delay(clock=20000000)
#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7, bits=8)
#endif

#include <stdlib.h>
#include <string.h>
//#include <input.c>
#define mode_h output_high(pin_e0);
#define mode_l output_low(pin_e0);

#define write_h_sound output_high(pin_e1);
#define write_l_sound output_low(pin_e1);

#define write_h_immersion output_high(pin_e2);
#define write_l_immersion output_low(pin_e2);

INT iresult;
char string1[10];
char string[10];
char sound[5];
char immersion[5];

#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7, bits=8)
#int_rda
void serial_isr() {
#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7, bits=8)
gets(string);
iresult=strlen(string);
strcpy(string1,string);

string[0x00]=' ';
string[0x01]=' ';
string[0x02]=' ';
string[0x03]=' ';
string[0x04]=' ';
string[0x05]=' ';
string[0x06]=' ';
string[0x07]=' ';
string[0x08]=' ';
string[0x09]=' ';
//string[0x0a]=' ';
//string[0x0b]=' ';
}

byte digit_num,data;

display_time();
disply_time();

display_sound();
disply_sound();

display_immersion();
disply_immersion();

main()
{
enable_interrupts(global);
enable_interrupts(int_rda);

delay_ms(5000);

string1[0x00]=0x00;
string1[0x01]=0x00;
string1[0x02]=0x00;
string1[0x03]=0x00;
string1[0x04]=0x00;
string1[0x05]=0x00;
string1[0x06]=0x00;
string1[0x07]=0x00;
string1[0x08]=0x00;
string1[0x09]=0x00;
//string1[0x0a]=0x00;
//string1[0x0b]=0x00;

while(1)
{

//if(string1[0x00]=='S')
//{

sound[0x00]=string1[0x00];
sound[0x01]=string1[0x01];
sound[0x02]=string1[0x02];
sound[0x03]=string1[0x03];
sound[0x04]=string1[0x04];
//}

//else if(string1[0x06]=='I')

//{
immersion[0x00]=string1[0x05];
immersion[0x01]=string1[0x06];
immersion[0x02]=string1[0x07];
immersion[0x03]=string1[0x08];
immersion[0x04]=string1[0x09];

//}

display_sound();
display_immersion();

#use rs232(baud=9600, xmit=PIN_c6, rcv=PIN_c7, bits=8)

}
}

disply_sound()
{
write_h_sound
mode_h
output_d(digit_num);
write_l_sound
write_h_sound
mode_l

OUTPUT_D(data);

write_l_sound
write_h_sound

}

disply_immersion()
{
write_h_immersion
mode_h
output_d(digit_num);
write_l_immersion
write_h_immersion
mode_l

OUTPUT_D(data);

write_l_immersion
write_h_immersion

}
////////////////////////////////Sound Velocity DISPLAY/////////////////////////
display_sound(){
output_low(pin_e1);

digit_num=0x58;
data=sound[0x04];
disply_sound();

digit_num=0x59;
data=sound[0x03];
disply_sound();

digit_num=0x5a;
data=sound[0x02];
disply_sound();

digit_num=0x5b;
data=sound[0x01];
disply_sound();

digit_num=0x5c;
data=sound[0x00];
disply_sound();
}
////////////////////////////////IMMERSION DISPLAY//////////////////////////////

display_immersion(){

output_low(pin_e0);
digit_num=0x58;
data=immersion[0x04];
disply_immersion();

digit_num=0x59;
data=immersion[0x03];
disply_immersion();

digit_num=0x5a;
data=immersion[0x02];
disply_immersion();

digit_num=0x5b;
data=immersion[0x01];
disply_immersion();

digit_num=0x5c;
data=immersion[0x00];
disply_immersion();
}

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