labsw/LOG: updated with latest results

labsw/LOG

@@ -104,7 +104,7 @@ Milled face plate #0:
   - correct banana jack hole diameter
 
 Milled face plate #1:
-- changes made
+- changes made:
   - increased engraving depth to 0.5 mm
   - increased banana jack hole diameter to 8.0 mm
 - defects found:
@@ -114,10 +114,46 @@ Milled face plate #1:
   - noticed that the button holes are milled last, after cutting the
     board outline. This explains the poor accuracy.
 
+--- Mon 2011-09-05 ------------------------------------------------------------
+
+Milled face plate #2:
+- changes made:
+  - board is unclad FR4
+  - added a bit more adhesive tape
+  - increased banana jack hole diameter from 8.0 mm to 8.1 mm, to
+    accommodate also jacks that are at the upper end of the tolerance
+    range
+  - corrected order of tool paths issues by cameo
+- measurements:
+  - board: 104.1-104.2 mm x 35.1 mm (nom. 104.0 mm x 35.0 mm)
+  - button hole: 12.5-12.6 mm x 11.3-11.4 mm (nom. 12.6 x 11.3 mm)
+- defects found:
+  - tight horizontal fit in the case
+  - LED holder have considerable play and retainer rings are loose to
+    the point of being useless
+  - adhesive tape now sticks almost too well :-) (it was hard to pry
+    the board loose after milling)
+
+Milled face plate #3:
+- changes made:
+  - reduced board width from 104.0 mm to 103.6 mm
+  - reduced LED hole from 6.9 mm to 6.2 mm
+- problems encountered:
+  - raw board wasn't quite large enough for the entire face plate, but
+    it seems I missed it by only < 0.1 mm.
+  - depth was too shallow, at the cost of the logo
+- measurements:
+  - board: 103.8 mm x 35.1 mm (nom. 103.6 mm x 35.0 mm)
+- defects found:
+  - LED holder works better but is still a bit wobbly
+  - (EE issue) there's a bit of current from 5 V through the opt-coupler
+    LEDs to the pull-ups. Work-around: add 10 kOhm in parallel to each
+    LED.
+
 ---------------------
 
-(next run)
+(next PCB run)
-- changes made
+- changes made:
   - made 5V relay traces go clearly for the centers of the respective pins
   - changed DIP hole size from 0.5 mm to 0.8 mm, hole-to-copper ratio from
     2.5 to 2
@@ -131,3 +167,8 @@ Pending:
 - add orientation markings on copper layer for MCU and DIP sockets
 - verify 2512 footprint of 1 W resistors
 - add ground zones
+- solve opto LED current. Three approaches:
+  1) add 10 k in parallel to LED (tested workaround)
+  2) disable internal pull-ups and add external pull-ups to IN_*
+     and to buttons
+  3) drive opto LEDs from 3.3 V instead of 5 V