MODIF - More comments

git-svn-id: svn+ssh://oldsvn/home/mlalondesvn/svn/cral@137 3ee9b42a-b53c-0410-a25e-f0b6218d5d5b
master
mlalondesvn 17 years ago
parent 9fbddf67bf
commit 26f18000a2

@ -1,16 +1,5 @@
extern "C" {
#include <avr/pgmspace.h>
#include <avr/interrupt.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <stdlib.h>
#include "wiring_private.h"
#include "wiring.h"
#include "WConstants.h"
#include <HardwareSerial.h>
#include "pins_arduino.h"
}
@ -19,6 +8,10 @@ extern "C" {
#define _HDQ_readPin() (*inputReg & bitmask)>>pin /* Change me to inline!*/
/**
* Constructor
* @param pin: pin number to attach to
**/
HDQ::HDQ(uint8_t pinArg)
{
pin = pinArg;
@ -29,98 +22,138 @@ HDQ::HDQ(uint8_t pinArg)
modeReg = portModeRegister(port);
}
/**
* sendBreak: writes a break to the HDQ line
**/
void HDQ::doBreak(void)
{
sbi(*modeReg, pin); // Set pin as output
cbi(*outputReg, pin); // Bring pin low
sbi(*modeReg, pin); // Set pin as output
// Wait the minimum break time
// Singal a break on the line
cbi(*outputReg, pin); // Bring pin low
delayMicroseconds(HDQ_DELAY_TB);
sbi(*outputReg, pin); // Bring the pin high again
// Wait the minimum break time
// Make sure we leave enough time for the slave to recover
cbi(*modeReg, pin); // Release pin
delayMicroseconds(HDQ_DELAY_TBR);
}
/**
* writeByte: write a raw byte of data to the bus
* @param payload: the byte to send
*
**/
void HDQ::writeByte(uint8_t payload)
{
sbi(*modeReg, pin); // Set pin as output
for (uint8_t ii = 0; ii < 8; ii++)
{
sbi(*modeReg, pin); // Set pin as output
cbi(*outputReg, pin); // Bring pin low
// Wait the minimum break time
// Start bit
cbi(*outputReg, pin); // Bring pin low
delayMicroseconds(HDQ_DELAY_BIT_START);
// Toggle the pin for this bit, LSB first
if (payload>>ii & 0x01) {
sbi(*outputReg, pin);
sbi(*outputReg, pin); // High
}
else {
cbi(*outputReg, pin);
cbi(*outputReg, pin); // Low
}
// Bit time
delayMicroseconds(HDQ_DELAY_BIT_WRITE);
sbi(*outputReg, pin);
// Stop bit
sbi(*outputReg, pin); // Bring the pin high
delayMicroseconds(HDQ_DELAY_BIT_END);
}
return;
}
boolean HDQ::write(uint8_t reg, uint8_t payload, boolean verif)
{
HDQ::write(reg, payload);
if (payload == HDQ::read(reg)) return true;
return false;
}
/**
* write: send a payload to the device
* @param reg: the address of the register to write to
* @param payload: data to be sent
* @return: false, unless if verif is set, then
* it will read back the register and
* return true if it matches the payload
**/
boolean HDQ::write(uint8_t reg, uint8_t payload)
{
// Singal a break
HDQ::doBreak();
// Write the register to write
HDQ::writeByte((reg |= HDQ_ADDR_MASK_WRITE));
// Wait for the slave to finish reading the register
delayMicroseconds((HDQ_DELAY_TRSPS_MAX - HDQ_DELAY_BIT_TOTAL) / 2);
// Write the payload
HDQ::writeByte(payload);
// Wait for the slave to finish writing the payload
delayMicroseconds((HDQ_DELAY_TRSPS_MAX - HDQ_DELAY_BIT_TOTAL) / 2);
cbi(*modeReg, pin); // Release pin
return true;
}
/**
* Write with verification
**/
boolean HDQ::write(uint8_t reg, uint8_t payload, boolean verif)
{
// Write the payload
HDQ::write(reg, payload);
// Verify the write
if (payload == HDQ::read(reg)) return true;
return false;
}
/**
* read: read from the device
* @param register: address of the register to read
* @return a uint8_t integer
**/
uint8_t HDQ::read(uint8_t reg)
{
uint8_t result = 0;
uint8_t maxTries = HDQ_DELAY_FAIL_TRIES; // ~128uS at 8Mhz with 8 instructions per loop
uint8_t ii;
// Singal a break
HDQ::doBreak();
// Write the register to read
HDQ::writeByte((reg |= HDQ_ADDR_MASK_READ));
for (ii = 0; ii < 8; ii++)
{
// Wait for the slave to toggle a low
// Wait for the slave to toggle a low, or fail
maxTries = HDQ_DELAY_FAIL_TRIES;
while (_HDQ_readPin() != 0 && maxTries-- > 0)
if (maxTries == 1) return 0xFF;
delayMicroseconds(HDQ_DELAY_BIT_WRITE / 2 + HDQ_DELAY_BIT_START); // 100 / 2 + 30
// Wait until Tdsub and half or one bit has passed
delayMicroseconds(HDQ_DELAY_BIT_WRITE / 2 + HDQ_DELAY_BIT_START);
// Read the bit
result |= _HDQ_readPin()<<ii;
delayMicroseconds(HDQ_DELAY_TSSUB - (HDQ_DELAY_BIT_WRITE / 2 + HDQ_DELAY_BIT_START) + 10); // pass Tssub
// Wait until Tssub has passed
delayMicroseconds(HDQ_DELAY_TSSUB - (HDQ_DELAY_BIT_WRITE / 2 + HDQ_DELAY_BIT_START) + 10);
// Wait for the slave to toggle a high again
// Wait for the slave to toggle a high, or fail
maxTries = HDQ_DELAY_FAIL_TRIES;
while (_HDQ_readPin() != 1 && maxTries-- > 0)
if (maxTries == 1) return 0xFF;
}
return result;

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