forked from IanF/OneWireArduinoSlaveATTINY85
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75 lines
2.5 KiB
75 lines
2.5 KiB
#include "Arduino.h" |
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#include "LowLevel.h" |
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#include "OneWireSlave.h" |
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#define LEDPin 13 |
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// This is the pin that will be used for one-wire data (depending on your arduino model, you are limited to a few choices, because some pins don't have complete interrupt support) |
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// On Arduino Uno, you can use pin 2 or pin 3 |
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#define OWPin 2 |
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Pin led(LEDPin); |
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// This is the ROM the arduino will respond to, make sure it doesn't conflict with another device |
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byte owROM[7] = { 0xE2, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02 }; |
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byte acknowledge = 0x42; |
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// This sample implements a simple protocol : sending match ROM, then the ROM, then 0x01 will turn the arduino light on. Sending 0x02 will turn it off. In each case, the byte 0x42 is sent as acknowledgement. |
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const byte CMD_TurnOn = 0x01; |
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const byte CMD_TurnOff = 0x02; |
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// This function will be called each time the OneWire library has an event to notify (reset, error, byte received) |
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void owReceive(OneWireSlave::ReceiveEvent evt, byte data); |
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void setup() |
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{ |
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led.outputMode(); |
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led.writeLow(); |
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// Setup the OneWire library |
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OneWire.setReceiveCallback(&owReceive); |
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OneWire.begin(owROM, OWPin); |
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} |
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void loop() |
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{ |
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delay(1); |
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// You can do anything you want here, the OneWire library works entirely in background, using interrupts. |
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cli();//disable interrupts |
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// Be sure to not block interrupts for too long, OneWire timing is very tight for some operations. 1 or 2 microseconds (yes, microseconds, not milliseconds) can be too much depending on your master controller, but then it's equally unlikely that you block exactly at the moment where it matters. |
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// This can be mitigated by using error checking and retry in your high-level communication protocol. A good thing to do anyway. |
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sei();//enable interrupts |
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} |
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void owReceive(OneWireSlave::ReceiveEvent evt, byte data) |
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{ |
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switch (evt) |
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{ |
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case OneWireSlave::RE_Byte: |
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if (data == CMD_TurnOn) |
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{ |
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led.writeHigh(); |
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} |
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else if (data == CMD_TurnOff) |
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{ |
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led.writeLow(); |
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} |
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else |
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{ |
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break; |
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} |
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// in this simple example we just reply with one byte to say we've processed the command |
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// a real application should have a CRC system to ensure messages are not corrupt, for both directions |
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// you can use the static OneWireSlave::crc8 method to add CRC checks in your communication protocol (it conforms to standard one-wire CRC checks, that is used to compute the ROM last byte for example) |
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OneWire.write(&acknowledge, 1, NULL); |
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break; |
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default: |
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; // we could also react to reset and error notifications, but not in this sample |
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} |
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}
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