forked from Longan-Labs/Arduino_CAN_BUS_MCP2515
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Merge pull request #10 from zkemble/master
Improved sleep functionality
- Loading branch information
Showing
5 changed files
with
219 additions
and
47 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,107 @@ | ||
| // CAN Sleep Example | ||
| // By Zak Kemble, based on the CAN receive example | ||
|
|
||
| // If you only have 2 devices on the CAN bus (the device running this sketch and some other device sending messages), then you may find that duplicate messages are received when waking up. | ||
| // This is because when the MCP2515 wakes up it enters LISTENONLY mode where it does not send ACKs to messages, so the transmitter will retransmit the same message a few times. | ||
|
|
||
| #include <mcp_can.h> | ||
| #include <SPI.h> | ||
| #include <avr/sleep.h> | ||
|
|
||
| #define CAN0_INT 2 // Set INT to pin 2 | ||
| MCP_CAN CAN0(10); // Set CS to pin 10 | ||
|
|
||
| void setup() | ||
| { | ||
| Serial.begin(115200); | ||
|
|
||
| // Initialize MCP2515 running at 16MHz with a baudrate of 500kb/s and the masks and filters disabled. | ||
| if(CAN0.begin(MCP_ANY, CAN_500KBPS, MCP_16MHZ) == CAN_OK) | ||
| Serial.println(F("MCP2515 Initialized Successfully!")); | ||
| else | ||
| Serial.println(F("Error Initializing MCP2515...")); | ||
|
|
||
| CAN0.setMode(MCP_NORMAL); // Set operation mode to normal so the MCP2515 sends acks to received data. | ||
| CAN0.setSleepWakeup(1); // Enable wake up interrupt when in sleep mode | ||
|
|
||
| pinMode(CAN0_INT, INPUT); // Configuring pin for /INT input | ||
|
|
||
| // Enable interrupts for the CAN0_INT pin (should be pin 2 or 3 for Uno and other ATmega328P based boards) | ||
| attachInterrupt(digitalPinToInterrupt(CAN0_INT), ISR_CAN, FALLING); | ||
|
|
||
| set_sleep_mode(SLEEP_MODE_PWR_DOWN); | ||
|
|
||
| Serial.println(F("MCP2515 Library Sleep Example...")); | ||
| } | ||
|
|
||
| void loop() | ||
| { | ||
| if(!digitalRead(CAN0_INT)) // If CAN0_INT pin is low, read receive buffer | ||
| { | ||
| unsigned long rxId; | ||
| byte len; | ||
| byte rxBuf[8]; | ||
|
|
||
| if(CAN0.readMsgBuf(&rxId, &len, rxBuf) == CAN_OK) // Read data: len = data length, buf = data byte(s) | ||
| { | ||
| char msgString[128]; // Array to store serial string | ||
| if(rxId & CAN_IS_EXTENDED) // Determine if ID is standard (11 bits) or extended (29 bits) | ||
| sprintf_P(msgString, PSTR("Extended ID: 0x%.8lX DLC: %1d Data:"), (rxId & CAN_EXTENDED_ID), len); | ||
| else | ||
| sprintf_P(msgString, PSTR("Standard ID: 0x%.3lX DLC: %1d Data:"), rxId, len); | ||
|
|
||
| Serial.print(msgString); | ||
|
|
||
| if(rxId & CAN_IS_REMOTE_REQUEST) // Determine if message is a remote request frame. | ||
| Serial.print(F(" REMOTE REQUEST FRAME")); | ||
| else | ||
| { | ||
| for(byte i=0;i<len;i++) | ||
| { | ||
| sprintf_P(msgString, PSTR(" 0x%.2X"), rxBuf[i]); | ||
| Serial.print(msgString); | ||
| } | ||
| } | ||
|
|
||
| Serial.println(); | ||
| } | ||
| else | ||
| Serial.println(F("Interrupt is asserted, but there were no messages to process...")); | ||
| } | ||
|
|
||
| Serial.println(F("SLEEPING...")); | ||
|
|
||
| // Put MCP2515 into sleep mode | ||
| // This can sometimes take upto around 100ms depending on what the chip is currently doing | ||
| CAN0.setMode(MCP_SLEEP); | ||
|
|
||
| Serial.println(F("SLEEP")); | ||
|
|
||
| // Clear serial buffers before sleeping | ||
| Serial.flush(); | ||
|
|
||
| // Put the microcontroller to sleep | ||
| cli(); // Disable interrupts | ||
| if(digitalRead(CAN0_INT)) // Make sure we havn't missed an interrupt between the digitalRead() above and now. If an interrupt happens between now and sei()/sleep_cpu() then sleep_cpu() will immediately wake up again | ||
| { | ||
| sleep_enable(); | ||
| sleep_bod_disable(); | ||
| sei(); | ||
| sleep_cpu(); | ||
| sleep_disable(); | ||
| } | ||
| sei(); | ||
|
|
||
| Serial.println(F("WAKE")); | ||
|
|
||
| CAN0.setMode(MCP_NORMAL); // When the MCP2515 wakes up it will be in LISTENONLY mode, here we put it into NORMAL mode | ||
| } | ||
|
|
||
| static void ISR_CAN() | ||
| { | ||
| // We don't do anything here, this is just for waking up the microcontroller | ||
| } | ||
|
|
||
| /********************************************************************************************************* | ||
| END FILE | ||
| *********************************************************************************************************/ |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Oops, something went wrong.