Diff: canutils.cpp

Revision:

1:d5452e398b76

Child:

2:bf3a2b29259a

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/canutils.cpp	Tue Sep 14 21:02:04 2010 +0000
@@ -0,0 +1,117 @@
+/*******************************************************************************
+
+canutils.cpp
+(c) 2010 by Sophie Dexter
+
+General purpose CAN bus functions for Just4Trionic by Just4pLeisure
+Functions that work with the CAN bus directly. Anything to do with the CAN bus
+must (should anyway) be done by one of these functions.
+
+********************************************************************************
+
+WARNING: Use at your own risk, sadly this software comes with no guarantees.
+This software is provided 'free' and in good faith, but the author does not
+accept liability for any damage arising from its use.
+
+*******************************************************************************/
+
+#include "canutils.h"
+
+//CAN can2(p30, p29);
+// Use a timer to see if things take too long
+Timer CANTimer;
+
+
+void can_open() {
+    // activate external can transceiver
+    can.reset();
+    can_rs_pin = 0;
+}
+
+void can_close() {
+    // disable external can transceiver
+    can_rs_pin = 1;
+    can.reset();
+}
+
+uint8_t can_set_speed(uint32_t speed) {
+    // 600kbit/s first - basically sets up CAN interface, but to wrong speed - not sure what else it does
+//    can.frequency(600000);
+    // 615kbit/s direct write of 615 kbit/s speed setting
+//    LPC_CAN2->BTR = 0x370002;
+    return (can.frequency(speed)) ? TERM_OK : TERM_ERR;
+}
+
+
+void show_can_message() {
+    CANMessage can_MsgRx;
+    if (can.read(can_MsgRx)) {
+        printf("w%03x%d", can_MsgRx.id, can_MsgRx.len);
+        for (char i=0; i<can_MsgRx.len; i++) {
+            printf("%02x", can_MsgRx.data[i]);
+        }
+        printf("\r\n");
+    }
+}
+
+//
+// Sends a CAN Message, returns FALSE if the message wasn't sent in time
+//
+// inputs:  integer CAN message 'id', pointer to 'frame', integer message length and integer timeout
+// return:     TRUE if the CAN message was sent before the 'timeout' expires
+//          FALSE if 'timeout' expires or the message length is wrong
+//
+extern bool can_send_timeout (uint32_t id, char *frame, uint8_t len, uint16_t timeout) {
+    CANTimer.reset();
+    CANTimer.start();
+    while (CANTimer.read_ms() < timeout) {
+        if (can.write(CANMessage(id, frame, len))) {
+            CANTimer.stop();
+            led1 = 1;
+            return TRUE;
+        }
+    }
+    can.reset();
+    CANTimer.stop();
+    return FALSE;
+}
+
+//
+// Waits for a CAN Message with the specified 'id' for a time specified by the 'timeout'
+// All other messages are ignored
+// The CAN message frame is returned using the pointer to 'frame'
+//
+// inputs:    integer CAN message 'id', pointer to 'frame' for returning the data
+//          integer expected length of message, len and integer for the waiting time 'timeout'
+//
+// return:    TRUE if a qualifying message was received
+//          FALSE if 'timeout' expires or the message length is wrong
+//
+extern bool can_wait_timeout (uint32_t id, char *frame, uint8_t len, uint16_t timeout) {
+    CANMessage CANMsgRx;
+    CANTimer.reset();
+    CANTimer.start();
+    while (CANTimer.read_ms() < timeout) {
+        if (can.read(CANMsgRx)) {
+/*
+            printf("w%03x8", CANMsgRx.id);
+            for (char i=0; i<len; i++) {
+                printf("%02x", CANMsgRx.data[i]);
+            }
+            printf("\n\r");
+//            */
+            led2 = 1;
+            if (CANMsgRx.id == id) {
+                CANTimer.stop();
+//                if (T5MsgRx.len != len)
+//                    return FALSE;
+                for (int i=0; i<len; i++)
+                    frame[i] = CANMsgRx.data[i];
+                return TRUE;
+            }
+        }
+    }
+    can.reset();
+    CANTimer.stop();
+    return FALSE;
+}