Tick Tock / CANary_corrupt

Dual CANbus monitor and instrumentation cluster

Eagle Schematic and Board design

/media/uploads/TickTock/canaryr5.zip

Parts List

Assembly

1) LCD Displays

I found ribbon cable is a nice way to organize the wires to the displays. You'll need 12 conductors and I connected them in the following order:

First I connected all the GND connections (IM0, IM1, IM3, & 2 GND). Do not connect the bottom GND until you have the ribbon cable connected. After making all the ribbon cable connections (connecting the GND of the ribbon cable to the bottom GND pad), solder the GND bar from the previous step to the back of the bottom GND connection. Finally, make a connection from the back side 3.3V pin to IM2. Take a break and repeat for the second display. Once the two displays are complete combine all wires except CS0, CS1, X+, X-, Y+, and Y-. Connect X- of the left display to X+ of the right. Similarly connect Y- of the left display to Y+ of the right. Insulate any exposed wires.

2) PCB

Refer to the schematics to place all the components on the board. If you plan to install into the CANary 3D enclosure, DO NOT install the battery holder or the socket for the mbed and, instead, connect two wires to the VB and GND pads nearby. You will have to install the battery holder against the back wall to avoid interfering with the right-hand display and the mbed will have to be directly soldered. I have not found a socket with a low enough profile to fit in the space provided (depth of enclosure is limited by the space behind the center console). Also, I recommend keeping as much lead as possible on the Zener diode (bending it as shown to clear the back wall). Although it is operating well within parameters, the Zener gets quite hot during extended operation and the leads help dissipate the heat and keep it away from the PCB and other components.

Once the PCB is populated, solder the LCDs to the PCB. CS0 connects to the right display and CS1 connects to the left.

3) Testing

4) Enclosure

The 3D printer leaves a lot of powder behind - I used a strong spray of water to get it out of all the cracks. The enclosure comes with a rather rough finish. I recommend convincing yourself you like it, then simply lightly sand then paint before assembly. Sanding is very difficult - the nylon is very nicely fused and doesn't want to sand. I tried sandblasting and that didn't work either. I had some limited success with filler and then sanding, but only on the outside - it is too difficult to sand the face.

5) Final Assembly

diff -r 1596b8644523 -r 9dcd70c32180 Util/mbedUtils.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Util/mbedUtils.cpp	Sun Feb 03 18:16:53 2013 +0000
@@ -0,0 +1,16 @@
+
+#include "mbedUtils.h"
+
+#include "mbed.h"
+
+
+int getFreeMemory()
+{
+    // Return the difference between the heap pointer and stack pointer.
+    char stackVar = '\0';
+    char* stackPtr = &stackVar;
+    char* heapPtr = (char*)malloc(sizeof(char));
+    int memFree = stackPtr - heapPtr;
+    free(heapPtr);
+    return memFree;
+}