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robertiko
Joined: 19 Feb 2016
Posts: 2
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| spi for pic12f?? |
 Posted: Fri Feb 19, 2016 12:46 am |
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hi i need a example for spi and pic12f
i know that i will use all pins but really i need ir
hola alguien tiene algun ejemplo con pic12f y spi
yo se que se usan todos los pines pero realmente necesito esto |
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robertiko
Joined: 19 Feb 2016
Posts: 2
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| Posted: Fri Feb 19, 2016 12:55 am |
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I try so, but gives me errors
| Code: | #include <12F683.h>
#device ADC=10
#fuses INTRC_IO,NOWDT,NOPUT,NOPROTECT,NOCPD,NOMCLR
#use delay(clock=4000000)
#define GP0 PIN_A5
#define GP1 PIN_A4
#define GP2 PIN_A3
#define GP3 PIN_A2
#define GP4 PIN_A1
#define GP5 PIN_A0
#use spi(DI=PIN_A2, DO=PIN_A1, CLK=PIN_A3)
void init()
{
set_tris_a( 0b11100001 ); // set GP0 output, all other inputs
setup_comparator( NC_NC_NC_NC ); // disable comparators
setup_adc_ports( NO_ANALOGS ); // disable analog inputs
setup_adc( ADC_OFF ); // disable A2D
}
main()
{
while ( TRUE ) // blink LED
{
spi_write(0x70);
}
} |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Feb 19, 2016 1:12 am |
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spi_write is only used with PICs that have a hardware SPI module.
| Quote: | while ( TRUE ) // blink LED
{
spi_write(0x70);
} |
For your PIC and with #use spi(), you should use spi_xfer() as shown
below. Then it will compile.
| Quote: | while ( TRUE ) // blink LED
{
spi_xfer(0x70);
} |
Also, at a minimum, you should add parameters for the number of bits
and the SPI mode. Example:
| Quote: | | #use spi(DI=PIN_A2, DO=PIN_A1, CLK=PIN_A3, bits=8, mode=0) |
#use spi() defaults to using 32 bits, but I think you only want 8 bits.
You need to specify it. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19477
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| Posted: Fri Feb 19, 2016 2:13 am |
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As a further comment, there are two ways of specifying the size to send.
The value used in the #USE statement, gives the _maximum_ that spi_xfer will send as a single transaction. You can specify for it to transfer less in the actual spi_xfer statement (but only if using streams).
Advantage of this is that if you want to send an int32 value, this can be sent with a single command.
So:
| Code: |
//using:
#use spi(DI=PIN_A2, DO=PIN_A1, CLK=PIN_A3, mode=0, stream=SPI)
//Then:
spi_xfer(SPI,0x70,8);
//will send just 8 bits
While:
spi_xfer(SPI,0x5555AAAA,32);
//will send 32bits
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This is 'why' CCS setup the command by default to transfer up to 32bits.
Given the largest variable supported by PCB/PCM/PCH, is 32 bits in size, it allows any standard variable to be sent in a single command. |
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