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Loic
Joined: 26 Feb 2004 Posts: 1
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Problem on I2C master 16F877 |
Posted: Thu Feb 26, 2004 4:37 am |
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Hi, I have write this code, but nothing happen on I2C pin I don't understand why! Could somebody help-me?
This is my master code
#include <16F877A.h>
#use delay(clock=16000000)
#fuses HS,NOWDT,NOPUT,NOLVP, NOBROWNOUT
#use i2c(master,sda=PIN_C4,scl=PIN_C3,force_hw,fast) // Hardware i2c
#include <protocol_i2c.h>
#define SLAVE_ADDR 0x40
void main() {
set_tris_b(0x00); //all output
// Program loops continuously
output_high(pin_b7);
while(1) {
output_low(pin_b6);
i2c_start();
output_low(pin_b7);
i2c_write(SLAVE_ADDR);
i2c_write(ilcd1);
i2c_write(Start_pos);
i2c_write(0x09);
i2c_stop();
delay_us(50);
output_High(pin_b6);
}
}
One thing strange is that pin B6 go high and low but pin C4 & C3 believe high.
Excuse my bad english and thanks to help me.
Lo�c |
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Markus
Joined: 30 Oct 2003 Posts: 13
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Posted: Thu Feb 26, 2004 7:19 am |
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Hi Loic,
try the following:
1. Code: | #fuses HS, NOWDT, NOPUT, NOLVP, NOBROWNOUT, NODEBUG |
2. don't forget that does also disable the i2c module (you are using the force_hw!).
Regards,
Markus |
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Guest
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Posted: Thu Feb 26, 2004 1:36 pm |
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Hi, thank you Markus for your answer. But there is two problem:
first one : my version of CCS (IDE 3.14, PCB & PCM 3.094) don't know "nodebug"!
second : if i'm don't use "force_hw", SCL is alwais low! (Of course I use pull-up!)
Regards,
Lo�c |
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Markus
Joined: 30 Oct 2003 Posts: 13
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Posted: Thu Feb 26, 2004 5:31 pm |
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Hi Loic,
is this directive supported by your compiler version? (sorry, never worked with Ver. 3.094)
Code: |
#device ICD = FALSE
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Otherwise try clearing the DEBUG bit (bit 11) of register 14-1 (p. 146 in 16F87xA datasheet pdf) by hand.
Hope this helps,
Markus
PS: Pins RB3, RB6 and RB7 are reserved for the In-Circiut Debugger (ICD), you have to turn it off to use them as normal IO-Ports. |
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