Friday May 8 2014
Vcc Power In: I connected to the wrong power pin on the
JTAG14 connector. I should have connected to JTAG Vcc/Tool (Pin 2),
not Vcc/Ext (Pin4).
FIX: Connect to JTAG Vcc/Tool (JTAG14 pin 2, TC2050 pin 2).
Put the External power jumper back in: JTAG pins 2 or 4 selected
by a jumper to connect to Vcc.
Rohm LEDs placed backwards: I now understand how to determine
the Pick Angle for the devices, and how to recognize the cathode (ground)
side of the physical LED.
FIX: Set pick angle to Normal.
R20 mistakenly included: I do not know why I placed R20
between the A3967 STEP input and Vcc; this was a schematic design
mistake.
FIX:Remove R20 from the schematic.
Tag-Connect does not work: I need to review the schematic
and possible send an email to the vendor. Neil at Tag-Connect pointed
out that my pads were in the wrong order. (Neil (877)244-4156,
Support@Tag-Connect.com)
WRONG: 6 7 8 9 10
1 2 3 4 5
CORRECT: 10 9 8 7 6
1 2 3 4 5
This makes sense because the TagConnect cable is a ribbon cable that is folded in half where it joins the board connector.
FIX: Correct the TC2050 component pattern, and everything should be fine after rerouting. There is still doubt about the TC power, so I will run TC pins 1 and 5 to a 3-post header that I can select using a jumper.TODO: I am still confused by the TC pinout. Neil said my schematic is correct, but looking at the TC cable it appears it is a straight 1:1 connection. Pin 1 on the 14pin header goes to pin 1 of the TC2050. This is not what I have.
I talked with Neil and he confirmed that it should be a 1:1 mapping, except that JTAG14:11 connects to TC2050:10. Refer to TagConnect for the mapping table.
Motor output misconfigured: In the future, I need to start
with the physical objects (the motors) and work back to the
components. I should have looked at the wiring harness for the motors
in hand and made sure the output pins would accomodate.
FIX: The Motor out pins should be (left to right):
GRN BLK BLU RED
OUT1B OUT1A OUT2B OUT2A
UPDATE: [20140911] The table above may be wrong! I believe it runs the motor, but in reverse. See Thermals for a revised table.
Driver runs too hot: I need to add a large copper area under
the A3967 to disperse the heat generated inside the IC. I also need to
widen the traces that carry the motor load current, even beyond the
current expanded size.
FIX: Fill the area under the A3967 with an exposed copper pour.
Make sure this area is not included in the top solder paste layer. I
will need to reroute signals so nothing passes under the part.
The next step is BlinkMtr02...