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rework the whole timing of the bus
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if needed you can configure overdrive speed (arduino would probably be
to slow)
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@orgua
orgua committed Feb 25, 2016
1 parent 2343b9b commit 9d39952
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Showing 4 changed files with 89 additions and 76 deletions.
4 changes: 3 additions & 1 deletion README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -29,13 +29,14 @@ The main goal is to use modern sensors (mainly [I2C](https://github.com/orgua/iL
- good documentation, numerous examples, easy interface for hub and sensors

### Recent development (latest at the top):
- rework of the whole timings, if needed you can configure overdrive speed (arduino would probably be to slow)
- bug fix: non conformal behaviour as a onewire-slave (hopefully)
- raise the maximal slave limit from 8 to 32, takes ~100b extra program-space
- open up for a lot more platforms with "platform.h" (taken from onewire-lib)
- fix bug: open-drain violation on slave side
- per-bit-CRC16 with sendAndCRC16() and sendAndCRC16() for load-balancing, 900ns/bit instead of 7µs/byte on Atmega328@16MHz
- add examples for onewire-master, for testing the bus
- rework of checkReset(), showPresence(), send(), recv() and the hole timings - Hub is much more reliable now and it saves ~120 byte program-space
- rework of checkReset(), showPresence(), send(), recv() - Hub is much more reliable now and it saves ~120 byte program-space
- faster CRC16 (ds2450 and ds2408 and ds2423), takes 5-7µs/byte instead of 10µs
- refactored the interface: hub.poll() replaces hub.waitForRequest()
- extended ds2890 to up to 4CH (datasheet has it covered), ds2413, ds2413 --> feature-complete
Expand All @@ -49,6 +50,7 @@ The main goal is to use modern sensors (mainly [I2C](https://github.com/orgua/iL
- test each example with real onewire-masters, for now it's tested with the onewire-lib and a loxone-system (ds18b20 passed)
- ~~DS1963S 0x18 iButton, datasheet under NDA~~
- [List of all Family-Codes](http://owfs.sourceforge.net/family.html)
- [List of Maxim Sensors](https://www.maximintegrated.com/en/app-notes/index.mvp/id/3989) (at the bottom)

### Connecting the HUB with the Network:

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2 changes: 1 addition & 1 deletion src/Arduino.h
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Original file line number Diff line number Diff line change
Expand Up @@ -40,7 +40,7 @@ uint8_t digitalPinToBitMask(uint8_t x);
uint32_t microsecondsToClockCycles(uint32_t x);

uint32_t micros(void); // takes about 3 µs to process @ 16 MHz
void delayMicroseconds(uint32_t x);
//void delayMicroseconds(uint32_t x);

void cli(void);
void sei(void);
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118 changes: 61 additions & 57 deletions src/OneWireHub.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -11,6 +11,8 @@ OneWireHub::OneWireHub(uint8_t pin)

baseReg = portInputRegister(digitalPinToPort(pin));

allow_long_pause = 0;

slave_count = 0;
slave_selected = nullptr;

Expand Down Expand Up @@ -239,6 +241,7 @@ bool OneWireHub::poll(void)
}



bool OneWireHub::checkReset(uint16_t timeout_us) // TODO: is there a specific high-time needed before a reset may occur?
{
volatile uint8_t *reg asm("r30") = baseReg;
Expand All @@ -248,32 +251,22 @@ bool OneWireHub::checkReset(uint16_t timeout_us) // TODO: is there a specific hi
DIRECT_MODE_INPUT(reg, pin_bitMask);
sei();

delayMicroseconds(ONEWIRE_TIME_BUS_CHANGE_MAX); // let the input settle
waitWhilePinIs(false, ONEWIRE_TIME_BUS_CHANGE_MAX); // let the input settle

// check if bus is low, since we are polling we don't know for how long it was zero
uint32_t time_trigger = micros() + timeout_us;
while (DIRECT_READ(reg, pin_bitMask))
{
if (micros() > time_trigger) return false;
// if reached this point (bus was high), this could be an indicator for a sleep after bus goes low
// was in code: https://github.com/orgua/OneWireHub/commit/f8e6bc2981581b333bda87b1034b0e69bf18a3b5
}
// wait for the bus to become low (master-controlled), since we are polling we don't know for how long it was zero
if (!waitWhilePinIs(1, timeout_us)) return false;

// wait for bus-release by master
time_trigger = micros() + ONEWIRE_TIME_RESET_MAX;
uint32_t time_start = micros();

while (!DIRECT_READ(reg, pin_bitMask))
// wait for bus-release by master
if (!waitWhilePinIs(0, ONEWIRE_TIME_RESET_MAX))
{
if (micros() > time_trigger)
{
_error = ONEWIRE_VERY_LONG_RESET;
return false;
}
_error = ONEWIRE_VERY_LONG_RESET;
return false;
}

// If the master pulled low for to short this will trigger an error
time_trigger -= ONEWIRE_TIME_RESET_MAX - ONEWIRE_TIME_RESET_MIN;
if (time_trigger > micros())
if ((time_start + ONEWIRE_TIME_RESET_MIN) > micros())
{
_error = ONEWIRE_VERY_SHORT_RESET;
return false;
Expand All @@ -288,32 +281,30 @@ bool OneWireHub::showPresence(void)
volatile uint8_t *reg asm("r30") = baseReg;

// Master will delay it's "Presence" check (bus-read) after the reset
delayMicroseconds(ONEWIRE_TIME_PRESENCE_SAMPLE_MIN);
waitWhilePinIs( 1, ONEWIRE_TIME_PRESENCE_SAMPLE_MIN); // no pincheck needed, but this avoids using "delay"

// pull the bus low and hold it some time
cli();
DIRECT_WRITE_LOW(reg, pin_bitMask);
DIRECT_MODE_OUTPUT(reg, pin_bitMask); // drive output low
sei();

delayMicroseconds(ONEWIRE_TIME_PRESENCE_LOW_STD);
waitWhilePinIs( 0, ONEWIRE_TIME_PRESENCE_LOW_STD); // no pincheck needed, but this avoids using "delay"

cli();
DIRECT_MODE_INPUT(reg, pin_bitMask); // allow it to float
sei();

// When the master or other slaves release the bus within a given time everything is fine
uint32_t time_trigger = micros() + (ONEWIRE_TIME_PRESENCE_LOW_MAX - ONEWIRE_TIME_PRESENCE_LOW_STD);
while (!DIRECT_READ(reg, pin_bitMask))
if (!waitWhilePinIs( 0, (ONEWIRE_TIME_PRESENCE_LOW_MAX - ONEWIRE_TIME_PRESENCE_LOW_STD)))
{
if (micros() > time_trigger)
{
_error = ONEWIRE_PRESENCE_LOW_ON_LINE;
return false;
}
_error = ONEWIRE_PRESENCE_LOW_ON_LINE;
return false;
}

// TODO: legacy code sleeps here a while
_error = ONEWIRE_NO_ERROR;
allow_long_pause = 1;
return true;
}

Expand Down Expand Up @@ -494,13 +485,14 @@ bool OneWireHub::sendBit(const bool value)
sei();
return false;
}
if (value) delayMicroseconds(32);
if (value) waitWhilePinIs( 0, ONEWIRE_TIME_READ_ONE_LOW_MAX); // no pincheck needed, but this avoids using "delay"
else
{
cli();
DIRECT_WRITE_LOW(reg, pin_bitMask);
DIRECT_MODE_OUTPUT(reg, pin_bitMask);
delayMicroseconds(32);
sei();
waitWhilePinIs( 0, ONEWIRE_TIME_WRITE_ZERO_LOW_STD); // no pincheck needed, but this avoids using "delay"
DIRECT_MODE_INPUT(reg, pin_bitMask);
}
sei();
Expand Down Expand Up @@ -559,16 +551,16 @@ uint8_t OneWireHub::recvBit(void)

cli();
DIRECT_MODE_INPUT(reg, pin_bitMask);

// wait for a low to high transition followed by a high to low within the time-out
if (!waitTimeSlot())
{
sei();
return false;
}

delayMicroseconds(30);
value = DIRECT_READ(reg, pin_bitMask);
sei();
waitWhilePinIs( 0, ONEWIRE_TIME_READ_STD); // no pincheck needed, but this avoids using "delay"
value = DIRECT_READ(reg, pin_bitMask);
return value;
}

Expand Down Expand Up @@ -597,42 +589,48 @@ uint8_t OneWireHub::recvAndCRC16(uint16_t &crc16)
return value;
}

bool OneWireHub::waitWhilePinIs(const bool value, const uint16_t timeout_us)
{
volatile uint8_t *reg asm("r30") = baseReg;
if (DIRECT_READ(reg, pin_bitMask) != value) return true; // shortcut

uint32_t time_trigger = micros() + timeout_us;
while (DIRECT_READ(reg, pin_bitMask) == value)
{
if (micros() > time_trigger) return false;
}
return true;
}

#define NEW_WAIT 0 // TODO: does not work as expected
#if (NEW_WAIT > 0)

// wait for a low to high transition followed by a high to low within the time-out
bool OneWireHub::waitTimeSlot(void)
{
volatile uint8_t *reg asm("r30") = baseReg;
sei();
//cli();
//volatile uint8_t *reg asm("r30") = baseReg;
//DIRECT_MODE_INPUT(reg, pin_bitMask);
//sei();
//While bus is low, retry until HIGH
if (!DIRECT_READ(reg, pin_bitMask))
if (!waitWhilePinIs( 0, ONEWIRE_TIME_SLOT_MAX))
{
uint32_t time_trigger = micros() + ONEWIRE_TIME_SLOT_MAX;
while (!DIRECT_READ(reg, pin_bitMask))
{
if (micros() > time_trigger)
{
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_LOW;
return false;
}
}
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_LOW;
return false;
}

if (DIRECT_READ(reg, pin_bitMask))
if (allow_long_pause)
{
//Wait for bus to fall form 1 to 0
uint32_t time_trigger = micros() + ONEWIRE_TIME_SLOT_MAX;
while (DIRECT_READ(reg, pin_bitMask))
{
if (micros() > time_trigger)
{
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_HIGH;
return false;
}
}
waitWhilePinIs( 1, 2000 );
allow_long_pause = 0;
}
cli();

if (!waitWhilePinIs( 1, ONEWIRE_TIME_SLOT_MAX ))
{
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_HIGH;
return false;
}

return true;
}

Expand All @@ -648,15 +646,21 @@ bool OneWireHub::waitTimeSlot(void)
while (!DIRECT_READ(reg, pin_bitMask))
{
if (--retries == 0)
{
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_LOW;
return false;
}
}

//Wait for bus to fall form 1 to 0
retries = TIMESLOT_WAIT_RETRY_COUNT;
while (DIRECT_READ(reg, pin_bitMask))
{
if (--retries == 0)
{
_error = ONEWIRE_READ_TIMESLOT_TIMEOUT_HIGH;
return false;
}
}
return true;
}
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41 changes: 24 additions & 17 deletions src/OneWireHub.h
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Original file line number Diff line number Diff line change
Expand Up @@ -38,11 +38,11 @@ class OneWireHub

/// the following TIME-values are in us and are taken from the ds2408 datasheet
// should be --> datasheet
// was --> in shagrat-legacy
// was --> shagrat-legacy
static constexpr uint16_t ONEWIRE_TIME_BUS_CHANGE_MAX = 5; // used

static constexpr uint16_t ONEWIRE_TIME_RESET_MIN = 380; // used, should be 480, and was 470
static constexpr uint16_t ONEWIRE_TIME_RESET_MAX = 720; // used
static constexpr uint16_t ONEWIRE_TIME_RESET_MAX = 960; // used, from ds2413

static constexpr uint16_t ONEWIRE_TIME_PRESENCE_HIGH_MIN = 15;
static constexpr uint16_t ONEWIRE_TIME_PRESENCE_HIGH_MAX = 60;
Expand All @@ -52,22 +52,27 @@ class OneWireHub
static constexpr uint16_t ONEWIRE_TIME_PRESENCE_LOW_MAX = 480; // used, should be 280, was 480 !!!! why

static constexpr uint16_t ONEWIRE_TIME_SLOT_MIN = 65;
static constexpr uint16_t ONEWIRE_TIME_SLOT_MAX =2000; // used, should be 120, was ~1050

static constexpr uint16_t ONEWIRE_TIME_WRITE_ZERO_LOW_MIN = 60;
static constexpr uint16_t ONEWIRE_TIME_WRITE_ZERO_LOW_MAX = 120;
static constexpr uint16_t ONEWIRE_TIME_WRITE_ONE_LOW_MIN = 15;
static constexpr uint16_t ONEWIRE_TIME_WRITE_ONE_LOW_MAX = 60;

static constexpr uint16_t ONEWIRE_TIME_READ_LOW_MIN = 5;
static constexpr uint16_t ONEWIRE_TIME_READ_LOW_MAX = 15;
static constexpr uint16_t ONEWIRE_TIME_READ_ZERO_LOW_MIN = 15;
static constexpr uint16_t ONEWIRE_TIME_READ_ZERO_LOW_MAX = 60;
static constexpr uint16_t ONEWIRE_TIME_SLOT_MAX = 240; // used, should be 120, was ~1050

// read and write from the viewpoint of the slave!!!!
static constexpr uint16_t ONEWIRE_TIME_READ_ZERO_LOW_MIN = 60;
static constexpr uint16_t ONEWIRE_TIME_READ_ZERO_LOW_MAX = 120;
static constexpr uint16_t ONEWIRE_TIME_READ_ONE_LOW_MIN = 15;
static constexpr uint16_t ONEWIRE_TIME_READ_ONE_LOW_MAX = 60; // used
static constexpr uint16_t ONEWIRE_TIME_READ_STD = 30; // used

static constexpr uint16_t ONEWIRE_TIME_WRITE_LOW_MIN = 5;
static constexpr uint16_t ONEWIRE_TIME_WRITE_LOW_MAX = 15;
static constexpr uint16_t ONEWIRE_TIME_WRITE_ZERO_LOW_MIN = 15;
static constexpr uint16_t ONEWIRE_TIME_WRITE_ZERO_LOW_STD = 35; // used
static constexpr uint16_t ONEWIRE_TIME_WRITE_ZERO_LOW_MAX = 60;
// TODO: define to switch to overdrive mode

uint8_t _error;

uint8_t pin_bitMask;
volatile uint8_t *baseReg;
uint8_t allow_long_pause;

uint8_t slave_count;
OneWireItem *slave_list[ONEWIRESLAVE_LIMIT]; // private slave-list (use attach/detach)
Expand All @@ -86,16 +91,18 @@ class OneWireHub
uint8_t getNrOfFirstBitSet(const uint32_t mask);
uint8_t getNrOfFirstFreeIDTreeElement(void);

bool recvAndProcessCmd();

bool waitTimeSlot();

bool checkReset(uint16_t timeout_us);

bool showPresence(void);

bool search(void);

bool recvAndProcessCmd();

bool waitTimeSlot();

bool waitWhilePinIs(const bool value, const uint16_t timeout_us);

public:

explicit OneWireHub(uint8_t pin);
Expand Down

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