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Thulsa-Doom
Joined: 18 Oct 2012
Posts: 3
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| Problem PIC18F4550 + ENC28J60 + DS1621 between SPI and I2C |
 Posted: Thu Oct 18, 2012 4:00 pm |
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Hi all, I'm new in the site and I have a problem that I don't know how to get out of it, I have run out of ideas and someone can help me.
I use CCS C + PIC18F4550 + ENC28J60 DS1621 and all done with the MPLAB IDE.
I'm implementing a PIC18F4550 with ENC28J60 Ethernet peripheral in the micro I have hosted a simple website, only to test, until then everything goes perfect.
The problem come when I attempting to add one more peripheral via the I2C protocol, I try to connect a temperature sensor (DS1621) but the system crashes.
when the system reads the line i2c_start(); the program enters in #use i2c(.....) and crashes.
I've been running the code in debugger mode via an ICD2 and upon reaching #use i2c (...) enters the routine protocol and is jumping between two records.
I upload a photo:
The records are:
| Code: | | BTFSS 0xf82 , 05 ACESS |
and
And hence not come out, whereupon the program is interrupted.
I tried with SPI hardware and software and in both cases the same thing happens
I don't know if this is a compiler bug or I did forget add something to code.
I know the problem is with the ENC28J60 driver because I delete the whole program and I've only left the driver of the ENC and a only function and when work the I2C routine happen the same.
copy and paste the main routine:
| Code: | #include <18F4550.h>
#fuses HSPLL,MCLR,NOWDT,NOPROTECT,NOLVP,NODEBUG,USBDIV,PLL5,CPUDIV1,VREGEN // Ocupa cristal 4Mhz, cambiar a PLL5 para ocuparlo con 20Mhz.
#use delay(clock=48000000)
#define ON output_high
#define OFF output_low
#define LedV PIN_A3
#define LedR PIN_A4
// Conexión entre el PIC18F4550 y el Modulo ENC28J60 (Se conecta directamente sin adaptador de voltajes).
// Se adjunta el datasheet del Modulo ENC28J60.
#ifndef PIN_ENC_MAC_SO
#define PIN_ENC_MAC_SO PIN_C7 // Conectar con PIN MISO del ENC28J60.
#define PIN_ENC_MAC_SI PIN_B4 // Conectar con PIN MOSI del ENC28J60.
#define PIN_ENC_MAC_CLK PIN_B2 // Conectar con PIN SCK del ENC28J60.
#define PIN_ENC_MAC_CS PIN_B3 // Conectar con PIN CS del ENC28J60.
#define PIN_ENC_MAC_RST PIN_B5 // Conectar con PIN RST del ENC28J60.
#define PIN_ENC_MAC_INT PIN_D2 // Conectar con PIN INT del ENC28J60.
#define PIN_ENC_MAC_WOL PIN_D3 // Conectar con PIN WOL del ENC28J60.
#define mac_enc_spi_tris_init() *0xF93=*0xF93 | 7; *0xF95=*0xF95 & 0xF0
#endif
#ifndef ENC_MAC_USE_SPI
#define ENC_MAC_USE_SPI TRUE
#endif
#include "Drivers/enc28j60.c"
#ifndef DAL_SCL
#define DAL_SCL PIN_C5
#define DAL_SDA PIN_C4
#endif
#include "Drivers/DS1621M.C"
void main(void){
int16 dato;
ON(LedR);
OFF(LedV);
mac_spi_init();
mac_reg_init();
init_temp(0x00);
while(TRUE){
ON(LedR);
delay_ms(50);
OFF(LedR);
delay_MS(50);
dato=enc_mac_read_phy_word(0x00);
}
} |
the driver of the ENC and the DS1621 are in PICC directory.
Sorry my poor english and thanks for all |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Oct 18, 2012 4:45 pm |
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| Quote: |
#include <18F4550.h>
#ifndef DAL_SCL
#define DAL_SCL PIN_C5
#define DAL_SDA PIN_C4
#endif
#include "Drivers/DS1621M.C"
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Look up pins C4 and C5 in the Overview section of the 18F4550 data sheet. What can those pins do ? |
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Thulsa-Doom
Joined: 18 Oct 2012
Posts: 3
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| Posted: Fri Oct 19, 2012 3:03 am |
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I have used these pins for I2C protocol software, but doesn't work.
I changed the pins, I used the pins SDA to B0 and SCL to B1, as written in the datasheet, these are the pins on the PIC18F4550 in I2C protocol and does not work.
I implemented the code for software in ENC28J60 leaving the pins B0 and B1 free for i2c and no work.
I implemented the code by software at all protocols and no work.
The codes work fine by separate.
I blocked I can't think of anything more |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19520
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| Posted: Fri Oct 19, 2012 3:49 am |
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The original pins are never going to work. If you look at the data sheet, C4, and C5, are _input only_ when used for normal applications. They don't support output, so cannot be used to drive I2C. This is what PCM programmer pointed you to.
Now, obvious comment, what is your pull up resistor value?. As you add more devices, the I2C bus gets longer, and has more capacitance. The required pull up decreases. If you are using a high value like 4K7, then you need to come down significantly. I'd suggest 1K2.
On the B0, & B1 pins, add the fuse NOPBADEN, or port B wakes up setup for ADC operation.
Hardware I2C, uses Schmitt trigger input buffers, so with these pins, having adequate pull up on the bus becomes even more important. Applies even if you use the 'software' library.
Best Wishes |
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Thulsa-Doom
Joined: 18 Oct 2012
Posts: 3
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| Posted: Fri Oct 19, 2012 1:34 pm |
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Well thanks for the help, the problem was the pull-up resistors.
I used the pins B2 and B4 for the I2C protocol, forced by hardware protocol and I installed a pull-up resistors and now works fine.
thank you very much |
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