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Message |
art
Joined: 21 May 2015
Posts: 181
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| 74595 problem |
 Posted: Sun Mar 03, 2019 9:30 pm |
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HI
I'm trying to send a byte number, for example if INPUT: 08, all output pins on 74595 ic will become HI. My code can compile, but no output at ic 74595 output when I input any number. Please help me how to solve this problem.
Thanks in advance.
| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,PROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7,ERRORS)
#include <string.h>
#include <input.c>
#include <stdio.h>
#include <stdlib.h>
#include <usb_cdc.h>
#include <74595.c>
void main()
{
BYTE data;
char c;
unsigned char d,key;
usb_init_cs();
while (TRUE)
{
usb_task();
if (usb_cdc_kbhit())
{
c=usb_cdc_getc();
if (c=='\n') {putc('\r'); putc('\n');}
if (c=='\r') {putc('\r'); putc('\n');}
while(true)
{
ART:
d = usb_cdc_getc();
if(d=='R') // push R for RELAY control
{
while (key!=32) // push SPACE BAR to stop
{
printf(usb_cdc_putc,"\r\nINPUT: ");
data =gethex_usb();
printf(usb_cdc_putc,"\n\r");
write_expanded_outputs (&data);
} key=0;
}
}
}
}
}
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Sun Mar 03, 2019 10:23 pm |
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| art wrote: | Please help me how to solve this problem.
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Troubleshoot it. Inspect intermediate program values. Add some
debugging code to do this. Example:
| Code: |
data =gethex_usb();
printf("Data from USB = %x \n\r", data); // Add this line
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Connect the RS232 output from your PIC board to your PC or laptop.
Run Teraterm or Putty, or some terminal program that you like and
see if you are really receiving what you expect from the USB. |
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art
Joined: 21 May 2015
Posts: 181
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| Posted: Mon Mar 04, 2019 12:33 am |
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OK, i've change it to :
| Code: |
data =gethex1_usb();
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if i input 3, data will show 03, but it still no output from 74595.
I've checked &data, it is always 86, what does it mean? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19497
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| Posted: Mon Mar 04, 2019 1:00 am |
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&data, will always be a fixed value. It is the _address_ where 'data' is stored.
It is what is stored at address '86', that is 'data'. This should be 3, when
you input '3'.
You need to now debug your output to the 74595. Send a couple of numbers
like '1', and '2' at an interval. Do they output?. If not you have a hardware
problem with the 74595 connections. |
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art
Joined: 21 May 2015
Posts: 181
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| Posted: Mon Mar 04, 2019 2:43 am |
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After I modified 74595.c file base on my hardware, it works but can only accept input number 0 until F, because of data format is BYTE.
I need to input FF, so all 8 output of 74595 ic will become HIGH.
What should I modified? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19497
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| Posted: Mon Mar 04, 2019 2:54 am |
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| Nothing. A byte is 8bits. The standard driver handles all 8bits. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Mon Mar 04, 2019 4:35 am |
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He said he modified the driver from this:
| Quote: | data =gethex_usb();
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to this:
| Quote: | OK, i've change it to :
data =gethex1_usb();
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gethex1 only gets 4 bits. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19497
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| Posted: Mon Mar 04, 2019 5:05 am |
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Aaargh....
Not the driver, but the code feeding the data into it. |
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art
Joined: 21 May 2015
Posts: 181
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| Posted: Mon Mar 04, 2019 6:15 pm |
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OK, i've change the code, and it works. When i send FF, all output 74595 will become HIGH. Next I change the code from input HEX number to input Decimel number. it also can work, when I send 255, all output 74595 will become HIGH. If I want to send decimel 65535 and make all 16 output from 2pcs 74595 ic, do I need to modified the driver ?
| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,PROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7,ERRORS)
#include <string.h>
#include <input.c>
#include <stdio.h>
#include <stdlib.h>
#include <usb_cdc.h>
#include <74595.c>
void main()
{
BYTE data;
char c;
unsigned char d,key;
usb_init_cs();
while (TRUE)
{
usb_task();
if (usb_cdc_kbhit())
{
c=usb_cdc_getc();
if (c=='\n') {putc('\r'); putc('\n');}
if (c=='\r') {putc('\r'); putc('\n');}
while(true)
{
ART:
d = usb_cdc_getc();
if(d=='R') // push R for RELAY control
{
while (key!=32) // push SPACE BAR to stop
{
printf(usb_cdc_putc,"\r\nINPUT: ");
data =gethex_usb();
printf(usb_cdc_putc,"\r\n %x \n\r");
write_expanded_outputs (&data);
} key=0;
}
}
}
}
}
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| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,PROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7,ERRORS)
#include <string.h>
#include <input.c>
#include <stdio.h>
#include <stdlib.h>
#include <usb_cdc.h>
#include <74595.c>
void main()
{
int8 ar;
char c;
unsigned char d,key;
usb_init_cs();
while (TRUE)
{
usb_task();
if (usb_cdc_kbhit())
{
c=usb_cdc_getc();
if (c=='\n') {putc('\r'); putc('\n');}
if (c=='\r') {putc('\r'); putc('\n');}
while(true)
{
ART:
d = usb_cdc_getc();
if(d=='R') // push R for RELAY control
{
while (key!=32) // push SPACE BAR to stop
{
get_string_usb(ar,6);
ar =get_int_usb();
write_expanded_outputs (&ar);
} key=0;
}
}
}
}
}
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art
Joined: 21 May 2015
Posts: 181
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| Posted: Mon Mar 04, 2019 11:34 pm |
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I already figure it out. Thank you for helping me.
Finally my code :
| Code: |
#include <18F4550.h>
#fuses HSPLL,NOWDT,PROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7,ERRORS)
#include <string.h>
#include <input.c>
#include <stdio.h>
#include <stdlib.h>
#include <usb_cdc.h>
#include <74595.c>
void main()
{
int16 ar;
char c;
unsigned char d,key;
usb_init_cs();
while (TRUE)
{
usb_task();
if (usb_cdc_kbhit())
{
c=usb_cdc_getc();
if (c=='\n') {putc('\r'); putc('\n');}
if (c=='\r') {putc('\r'); putc('\n');}
while(true)
{
ART:
d = usb_cdc_getc();
if(d=='R') // push R for RELAY control
{
while (key!=32) // push SPACE BAR to stop
{
ar =get_long_usb();
write_expanded_outputs (&ar);
} key=0;
}
}
}
}
}
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Ttelmah
Joined: 11 Mar 2010
Posts: 19497
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| Posted: Tue Mar 05, 2019 1:28 am |
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Your original code with gethex, would have worked provided you were
happy to type two hex digits.
You changed this to gethex1,, which can only get one digit. Which is
why you could only access 4 bits.
You are now unnecessarily using getlong, which can get a 16bit value
though you are only outputting an int8. Simple getint will give smaller
code and still give you the 8 bits.
Using getint, or getlong implies also you are now having to put the number
in decimal not hex. Question of which is easier/better?.
You need to start understanding 'sizes'. int8 = 8 bits.
'long'= int16 = 16bits.
One hex digit = 4bits. |
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temtronic
Joined: 01 Jul 2010
Posts: 9221
Location: Greensville,Ontario
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| Posted: Tue Mar 05, 2019 6:21 am |
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just saw this.....
unsigned char d,key;
In CCS C, 'char' is an unsigned 8 bit variable, so you don't need to type 'unsigned' in front of it. It should save you a lot of typing. Since I can't touchtype ANY 'shortcut' is welcomed!
To me a 'char' is 0....255 ( always a positive number).
CCS also has BYTE ( it's in the device header), but as an int8. That I think of as any number from -128..+127.
The 'fun' begins when you switch to a different series PIC. The bigger PICS are 16bit based, not 8 bit. And if you come from the PC world,they're diffrent too.
so... it's always a GREAT idea to declare variables and see what the 'default' settings are..
This is all probably documented 'somewhere' that we never read it
Jay |
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dluu13
Joined: 28 Sep 2018
Posts: 395
Location: Toronto, ON
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| Stdint |
| Posted: Tue Mar 05, 2019 6:40 am |
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| For numbers, I usually just go right ahead and include the stdint.h header. Then I can use uint8_t, int8_t, etc. And I know immediately whether they are signed or unsigned and their max/min values. |
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art
Joined: 21 May 2015
Posts: 181
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| Posted: Tue Mar 05, 2019 7:46 am |
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| Ttelmah wrote: |
'long'= int16 = 16bits.
One hex digit = 4bits.
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if i want to use 4 units of 74595, so i need to use int32. is it correct?
int32= long ? |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19497
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| Posted: Tue Mar 05, 2019 8:01 am |
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Yes, and get_int32.
You made no mention before of multiple 74595's.
More likely to be really useful, is to use gethex, four times, and work
with four separate bytes. Honestly a lot easier to control pins with
something like
11223344 Hex, rather than 287454020.
With the former you can see 'at once' which bits are on and off.
Last edited by Ttelmah on Tue Mar 05, 2019 8:14 am; edited 1 time in total |
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