Add: random packets generator example

2026-07-27 19:55:59 +00:00 · 2020-12-27 13:01:40 +08:00
parent fc04762c9e
commit 06cf5a136d
1 changed files with 120 additions and 0 deletions
@@ -0,0 +1,120 @@
+/*
+ * demo: CAN-BUS Shield, send random id/type/data
+ * This code has a little same with linux can-utils 'cangen -mv'
+ *
+ * Copyright (C) 2020 Seeed Technology Co.,Ltd.
+ */
+#include <SPI.h>
+
+/*SAMD core*/
+#ifdef ARDUINO_SAMD_VARIANT_COMPLIANCE
+    #define SERIAL SerialUSB
+#else
+    #define SERIAL Serial
+#endif
+
+#define CAN_2515
+// #define CAN_2518FD
+
+// the cs pin of the version after v1.1 is default to D9
+// v0.9b and v1.0 is default D10
+
+// Set SPI CS Pin according to your hardware
+// For Wio Terminal w/ MCP2518FD RPi Hat：
+// Channel 0 SPI_CS Pin: BCM 8
+// Channel 1 SPI_CS Pin: BCM 7
+// Interupt Pin: BCM25
+// *****************************************
+// For Arduino MCP2515 Hat:
+// SPI_CS Pin: D9
+
+#ifdef CAN_2518FD
+#include "mcp2518fd_can.h"
+const int SPI_CS_PIN = 9;
+const int CAN_INT_PIN = 2;
+mcp2518fd CAN(SPI_CS_PIN); // Set CS pin
+#define MAX_DATA_SIZE 64
+#endif
+
+#ifdef CAN_2515
+#include "mcp2515_can.h"
+const int SPI_CS_PIN = 9;
+const int CAN_INT_PIN = 2;
+mcp2515_can CAN(SPI_CS_PIN); // Set CS pin
+#define MAX_DATA_SIZE 8
+#endif
+
+void setup() {
+    SERIAL.begin(115200);
+    while(!Serial){};
+
+#ifdef CAN_2518FD
+    while (0 != CAN.begin((byte)CAN_500K_1M)) {            // init can bus : baudrate = 500k
+#else
+    while (CAN_OK != CAN.begin(CAN_500KBPS)) {             // init can bus : baudrate = 500k
+#endif
+        SERIAL.println("CAN BUS Shield init fail");
+        SERIAL.println(" Init CAN BUS Shield again");
+        delay(100);
+    }
+    SERIAL.println("CAN BUS Shield init ok!");
+
+    randomSeed(millis());
+}
+
+uint32_t id;
+uint8_t  type; // bit0: ext, bit1: rtr
+unsigned len;
+byte cdata[MAX_DATA_SIZE] = {0};
+
+void loop() {
+    type = random(4);
+    if (type & 0x1) {
+        // total 29 bits
+        // Arduino AVR only generate up to 16 bits random number
+        id = random(0x1U << 14);
+        id |= (uint32_t)random(0x1U << 15) << 14;
+    } else {
+        id = random(0x1U << 11);
+    }
+    if (type & 0x2) {
+        len = 0;
+        // remote frame could also carry data
+        // but don't do it.
+        // len = random(0, MAX_DATA_SIZE + 1);
+    } else {
+        len = random(0, MAX_DATA_SIZE + 1);
+    }
+
+    int i;
+    for (i = 0; i < len; i++) {
+        cdata[i] = random(0x100);
+    }
+
+    CAN.sendMsgBuf(id, bool(type & 0x1),
+                       bool(type & 0x2),
+                       len, cdata);
+    char prbuf[0x40];
+    int n;
+
+    /* Displayed type:
+     *
+     * 0x00: standard data frame
+     * 0x02: extended data frame
+     * 0x30: standard remote frame
+     * 0x32: extended remote frame
+     */
+    static const byte type2[] = {0x00, 0x02, 0x30, 0x32};
+    n = sprintf(prbuf, "TX: [%08lX](%02X) ", (unsigned long)id, type2[type]);
+    // n = sprintf(prbuf, "TX: [%08lX](%02X) ", id, type);
+
+    for (i = 0; i < len; i++) {
+        n += sprintf(prbuf + n, "%02X ", cdata[i]);
+    }
+    SERIAL.println(prbuf);
+
+    unsigned d = random(30);
+    SERIAL.println(d);
+    delay(d);
+}
+// END FILE