mcp2515: add support for mcp2515 CAN device

examples/mcp2515/main.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"fmt"
+	"machine"
+	"time"
+
+	"tinygo.org/x/drivers/mcp2515"
+)
+
+var (
+	spi   = machine.SPI0
+	csPin = machine.D5
+)
+
+func main() {
+	spi.Configure(machine.SPIConfig{
+		Frequency: 115200,
+		SCK:       machine.SPI0_SCK_PIN,
+		SDO:       machine.SPI0_SDO_PIN,
+		SDI:       machine.SPI0_SDI_PIN,
+		Mode:      0})
+	can := mcp2515.New(spi, csPin)
+	can.Configure()
+	err := can.Begin(mcp2515.CAN500kBps, mcp2515.Clock8MHz)
+	if err != nil {
+		failMessage(err.Error())
+	}
+
+	for {
+		err := can.Tx(0x111, 8, []byte{0x00, 0xAA, 0x55, 0xAA, 0x55, 0xAA, 0x55, 0xAA})
+		if err != nil {
+			failMessage(err.Error())
+		}
+		if can.Received() {
+			msg, err := can.Rx()
+			if err != nil {
+				failMessage(err.Error())
+			}
+			fmt.Printf("CAN-ID: %03X dlc: %d data: ", msg.ID, msg.Dlc)
+			for _, b := range msg.Data {
+				fmt.Printf("%02X ", b)
+			}
+			fmt.Print("\r\n")
+		}
+		time.Sleep(time.Millisecond * 500)
+	}
+}
+
+func failMessage(msg string) {
+	for {
+		println(msg)
+		time.Sleep(1 * time.Second)
+	}
+}