Michel2/Seeed_Arduino_CAN
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Dmitry
2016-01-06 20:39:20 +03:00
parent 5a84e4a715
commit 0a91d60293
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README.md
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@@ -21,38 +21,40 @@ CAN-BUS is a common industrial bus because of its long travel distance, medium c
To create connection with MCP2515 provide pin number where SPI CS is connected (10 by default) and mode
The available modes are listed as follows:
MCP_CAN::MODE_NORMAL,
MCP_CAN::MODE_LOOPBACK,
MCP_CAN::MODE_LISTENONLY
```C++
MCP_CAN::MODE_NORMAL,
MCP_CAN::MODE_LOOPBACK,
MCP_CAN::MODE_LISTENONLY
```
To work with network set baudrate.
The available baudrates are listed as follows:
enum CAN_SPEED {
CAN_5KBPS,
CAN_10KBPS,
CAN_20KBPS,
CAN_31K25BPS,
CAN_33KBPS,
CAN_40KBPS,
CAN_50KBPS,
CAN_80KBPS,
CAN_83K3BPS,
CAN_95KBPS,
CAN_100KBPS,
CAN_125KBPS,
CAN_200KBPS,
CAN_250KBPS,
CAN_500KBPS,
CAN_1000KBPS
};
```C++
enum CAN_SPEED {
CAN_5KBPS,
CAN_10KBPS,
CAN_20KBPS,
CAN_31K25BPS,
CAN_33KBPS,
CAN_40KBPS,
CAN_50KBPS,
CAN_80KBPS,
CAN_83K3BPS,
CAN_95KBPS,
CAN_100KBPS,
CAN_125KBPS,
CAN_200KBPS,
CAN_250KBPS,
CAN_500KBPS,
CAN_1000KBPS
};
```
<br>
Example of inititalization
MCP_CAN mcp2551(10, MCP_CAN::MODE_LOOPBACK);
mcp2551->begin(CAN_125KBPS);
```C++
MCP_CAN mcp2551(10, MCP_CAN::MODE_LOOPBACK);
mcp2551->begin(CAN_125KBPS);
```
<br>
Note: To transfer data on high speed of CAN interface via UART dont forget to update UART baudrate as necessary.
@@ -63,8 +65,10 @@ There are 2 receive mask registers and 5 filter registers on the controller chip
We provide two functions for you to utilize these mask and filter registers. They are:
init_Mask(unsigned char num, unsigned char ext, unsigned char ulData);
init_Filt(unsigned char num, unsigned char ext, unsigned char ulData);
```C++
init_Mask(unsigned char num, unsigned char ext, unsigned char ulData);
init_Filt(unsigned char num, unsigned char ext, unsigned char ulData);
```
**num** represents which register to use. You can fill 0 or 1 for mask and 0 to 5 for filter.
@@ -76,15 +80,16 @@ We provide two functions for you to utilize these mask and filter registers. The
<br>
## 3. Send Data
MCP_CAN::ERROR sendMessage(const MCP_CAN::TXBn txbn, const struct can_frame *frame);
MCP_CAN::ERROR sendMessage(const struct can_frame *frame);
```C++
MCP_CAN::ERROR sendMessage(const MCP_CAN::TXBn txbn, const struct can_frame *frame);
MCP_CAN::ERROR sendMessage(const struct can_frame *frame);
```
This is a function to send data onto the bus.
For example, In the 'send' example, we have:
<pre>
```C++
struct can_frame frame;
frame.can_id = 0x000;
frame.can_dlc = 4;
@@ -94,9 +99,9 @@ frame.data[2] = 0xFF;
frame.data[3] = 0xFF;
CAN.sendMessage(&frame); //send out the message to the bus and tell other devices this is a standard frame from 0x00.
</pre>
```
<pre>
```C++
struct can_frame frame;
frame.can_id = 0x12345678 | CAN_EFF_MASK;
frame.can_dlc = 2;
@@ -104,7 +109,7 @@ frame.data[0] = 0xFF;
frame.data[1] = 0xFF;
CAN.sendMessage(MCP_CAN::TXB1, &frame); // send out the message to the bus using second TX buffer and tell other devices this is a extended frame from 0x12345678.
</pre>
```
<br>
@@ -112,8 +117,10 @@ CAN.sendMessage(MCP_CAN::TXB1, &frame); // send out the message to the bus using
The following function is used to receive data on the 'receive' node:
MCP_CAN::ERROR readMessage(const MCP_CAN::RXBn rxbn, struct can_frame *frame);
MCP_CAN::ERROR readMessage(struct can_frame *frame);
```C++
MCP_CAN::ERROR readMessage(const MCP_CAN::RXBn rxbn, struct can_frame *frame);
MCP_CAN::ERROR readMessage(struct can_frame *frame);
```
In conditions that masks and filters have been set. This function can only get frames that meet the requirements of masks and filters.
@@ -121,47 +128,49 @@ You can choise one of two method to receive: interrup-based and polling
Example of poll read
void loop() {
struct can_frame frame;
if (mcp2551.readMessage(&frame) == MCP_CAN::ERROR_OK) {
// frame contains received message
}
}
```C++
void loop() {
struct can_frame frame;
if (mcp2551.readMessage(&frame) == MCP_CAN::ERROR_OK) {
// frame contains received message
}
}
```
Example of interrupt based read
bool interrupt = false;
struct can_frame frame;
```C++
bool interrupt = false;
struct can_frame frame;
void irqHandler() {
interrupt = true;
}
void irqHandler() {
interrupt = true;
}
void setup() {
...
attachInterrupt(0, irqHandler, FALLING);
}
void setup() {
...
attachInterrupt(0, irqHandler, FALLING);
}
void loop() {
if (interrupt) {
interrupt = false;
void loop() {
if (interrupt) {
interrupt = false;
uint8_t irq = mcp2551.getInterrupts();
uint8_t irq = mcp2551.getInterrupts();
if (irq & MCP_CAN::CANINTF_RX0IF) {
if (mcp2551.readMessage(MCP_CAN::RXB0, &frame) == CanHacker::ERROR_OK) {
// frame contains received from RXB0 message
}
}
if (irq & MCP_CAN::CANINTF_RX0IF) {
if (mcp2551.readMessage(MCP_CAN::RXB0, &frame) == CanHacker::ERROR_OK) {
// frame contains received from RXB0 message
}
}
if (irq & MCP_CAN::CANINTF_RX1IF) {
if (mcp2551.readMessage(MCP_CAN::RXB1, &frame) == CanHacker::ERROR_OK) {
// frame contains received from RXB1 message
}
}
}
}
if (irq & MCP_CAN::CANINTF_RX1IF) {
if (mcp2551.readMessage(MCP_CAN::RXB1, &frame) == CanHacker::ERROR_OK) {
// frame contains received from RXB1 message
}
}
}
}
```
<br>
## 5. Examples