Update README, project cleanup

README.md

@@ -1,38 +1,49 @@
 # Necroware's NW12887 RTC module
 
-![photo](./photo.jpg)
+![photo](./images/top.jpg)
 
 This is a drop-in replacement for RTC modules with solid body. Such modules were
 widely used on 486 and Pentium mainboards back in the days. After so many years
 the battery inside of such modules got empty and there is no way to exchange it.
 With empty battery BIOS settings can not be saved and so many mainboards can't
 even boot properly. This alternative solution has a socket for CR1225 and the
-battery can be easily replaced again, when it gets empty.
+battery can be easily replaced again, when it gets empty. This module can be
+used with BQ3285, BQ4285 or pin compatible RTC chips, dependent on the
+requirements.
 
 This part should be compatible with following RTC modules:
 
 * Dallas DS1287 / DS12887 / DS12B887 (using BQ3285)
 * Benchmarq BQ3287 (using BQ3285)
-* ODIN OEC12C887 (using BQ3285)
 * Benchmarq BQ4287 (using BQ4285)
+* ODIN OEC12C887 (using BQ3285)
+
+## Remarks to the used RTC chips
+
+Pay attention, which RTC IC you need. Most of the mainboards with an RTC module
+need BQ3285, but some EISA mainboards require BQ4285 with chip enable signaling
+on pins 21/22 to control external memory.
 
+## Cutting the module pins
+
+Dependent on which RTC chip you are using you have to cut off some pins on the
+module. If you are using BQ3285, you need to remove pins 2,3,16,20,21,22. When
+using BQ4285 you need to remove pins 2,3,16,20.
+
+![photo](./images/pinout.jpg)
+![photo](./images/bottom.jpg)
 
 ## Bill of Materials
 
 Part | # | Description
 -----|---|-----------------------------------------
-U1   | 1 | Real-Time Clock BQ4285S (or BQ3285S) SO-24
+U1   | 1 | Real-Time Clock BQ3285S or BQ4285S SO-24
 Y1   | 1 | Crystal oscillator 32kHz 6pF
 BT1  | 1 | CR1220 / CR1225 SMD battery holder
 
 
-## Remarks to the used RTC chips
 
-Pay attention, which RTC IC you need. Most of the mainboards need BQ3285, but
-EISA mainboards require BQ4285 with chip enable signaling on pins 21/22 to 
-control external RAM IC. Since BQ4285 should be else compatible to BQ3285,
-it is probably sufficient just to always use BQ4285 and snap off the related
-pins 21/22 if only BQ3285 functionality is needed.
+
 
 
 

kicad/nwX287.kicad_pcb

@@ -144,6 +144,9 @@
     (add_net DS)
     (add_net INT)
     (add_net MOT)
+    (add_net "Net-(U2-Pad2)")
+    (add_net "Net-(U2-Pad20)")
+    (add_net "Net-(U2-Pad3)")
     (add_net RST)
     (add_net RW)
     (add_net SQW)
@@ -175,24 +178,24 @@
     (fp_text value bq4285 (at 0 -0.635 180) (layer B.SilkS)
       (effects (font (size 1 1) (thickness 0.15)) (justify mirror))
     )
-    (fp_line (start 5.93 7.95) (end -5.93 7.95) (layer B.CrtYd) (width 0.05))
-    (fp_line (start 5.93 -7.95) (end 5.93 7.95) (layer B.CrtYd) (width 0.05))
-    (fp_line (start -5.93 -7.95) (end 5.93 -7.95) (layer B.CrtYd) (width 0.05))
-    (fp_line (start -5.93 7.95) (end -5.93 -7.95) (layer B.CrtYd) (width 0.05))
-    (fp_line (start -3.75 6.7) (end -2.75 7.7) (layer B.Fab) (width 0.1))
-    (fp_line (start -3.75 -7.7) (end -3.75 6.7) (layer B.Fab) (width 0.1))
-    (fp_line (start 3.75 -7.7) (end -3.75 -7.7) (layer B.Fab) (width 0.1))
-    (fp_line (start 3.75 7.7) (end 3.75 -7.7) (layer B.Fab) (width 0.1))
-    (fp_line (start -2.75 7.7) (end 3.75 7.7) (layer B.Fab) (width 0.1))
-    (fp_line (start -3.86 7.545) (end -5.675 7.545) (layer B.SilkS) (width 0.12))
-    (fp_line (start -3.86 7.81) (end -3.86 7.545) (layer B.SilkS) (width 0.12))
-    (fp_line (start 0 7.81) (end -3.86 7.81) (layer B.SilkS) (width 0.12))
-    (fp_line (start 3.86 7.81) (end 3.86 7.545) (layer B.SilkS) (width 0.12))
-    (fp_line (start 0 7.81) (end 3.86 7.81) (layer B.SilkS) (width 0.12))
-    (fp_line (start -3.86 -7.81) (end -3.86 -7.545) (layer B.SilkS) (width 0.12))
-    (fp_line (start 0 -7.81) (end -3.86 -7.81) (layer B.SilkS) (width 0.12))
-    (fp_line (start 3.86 -7.81) (end 3.86 -7.545) (layer B.SilkS) (width 0.12))
     (fp_line (start 0 -7.81) (end 3.86 -7.81) (layer B.SilkS) (width 0.12))
+    (fp_line (start 3.86 -7.81) (end 3.86 -7.545) (layer B.SilkS) (width 0.12))
+    (fp_line (start 0 -7.81) (end -3.86 -7.81) (layer B.SilkS) (width 0.12))
+    (fp_line (start -3.86 -7.81) (end -3.86 -7.545) (layer B.SilkS) (width 0.12))
+    (fp_line (start 0 7.81) (end 3.86 7.81) (layer B.SilkS) (width 0.12))
+    (fp_line (start 3.86 7.81) (end 3.86 7.545) (layer B.SilkS) (width 0.12))
+    (fp_line (start 0 7.81) (end -3.86 7.81) (layer B.SilkS) (width 0.12))
+    (fp_line (start -3.86 7.81) (end -3.86 7.545) (layer B.SilkS) (width 0.12))
+    (fp_line (start -3.86 7.545) (end -5.675 7.545) (layer B.SilkS) (width 0.12))
+    (fp_line (start -2.75 7.7) (end 3.75 7.7) (layer B.Fab) (width 0.1))
+    (fp_line (start 3.75 7.7) (end 3.75 -7.7) (layer B.Fab) (width 0.1))
+    (fp_line (start 3.75 -7.7) (end -3.75 -7.7) (layer B.Fab) (width 0.1))
+    (fp_line (start -3.75 -7.7) (end -3.75 6.7) (layer B.Fab) (width 0.1))
+    (fp_line (start -3.75 6.7) (end -2.75 7.7) (layer B.Fab) (width 0.1))
+    (fp_line (start -5.93 7.95) (end -5.93 -7.95) (layer B.CrtYd) (width 0.05))
+    (fp_line (start -5.93 -7.95) (end 5.93 -7.95) (layer B.CrtYd) (width 0.05))
+    (fp_line (start 5.93 -7.95) (end 5.93 7.95) (layer B.CrtYd) (width 0.05))
+    (fp_line (start 5.93 7.95) (end -5.93 7.95) (layer B.CrtYd) (width 0.05))
     (fp_text user bq3285 (at 0 1.27) (layer B.SilkS)
       (effects (font (size 1 1) (thickness 0.15)) (justify mirror))
     )
@@ -262,19 +265,19 @@
     (fp_text value bq4285 (at 7.62 30.27) (layer F.Fab) hide
       (effects (font (size 1 1) (thickness 0.15)))
     )
-    (fp_line (start 1.255 -1.27) (end 14.985 -1.27) (layer F.Fab) (width 0.1))
-    (fp_line (start 14.985 -1.27) (end 14.985 29.21) (layer F.Fab) (width 0.1))
-    (fp_line (start 14.985 29.21) (end 0.255 29.21) (layer F.Fab) (width 0.1))
-    (fp_line (start 0.255 29.21) (end 0.255 -0.27) (layer F.Fab) (width 0.1))
-    (fp_line (start 0.255 -0.27) (end 1.255 -1.27) (layer F.Fab) (width 0.1))
-    (fp_line (start -1.27 -1.33) (end -1.27 29.27) (layer F.Fab) (width 0.1))
-    (fp_line (start -1.27 29.27) (end 16.51 29.27) (layer F.Fab) (width 0.1))
-    (fp_line (start 16.51 29.27) (end 16.51 -1.33) (layer F.Fab) (width 0.1))
-    (fp_line (start 16.51 -1.33) (end -1.27 -1.33) (layer F.Fab) (width 0.1))
-    (fp_line (start -1.55 -1.6) (end -1.55 29.55) (layer F.CrtYd) (width 0.05))
-    (fp_line (start -1.55 29.55) (end 16.8 29.55) (layer F.CrtYd) (width 0.05))
-    (fp_line (start 16.8 29.55) (end 16.8 -1.6) (layer F.CrtYd) (width 0.05))
     (fp_line (start 16.8 -1.6) (end -1.55 -1.6) (layer F.CrtYd) (width 0.05))
+    (fp_line (start 16.8 29.55) (end 16.8 -1.6) (layer F.CrtYd) (width 0.05))
+    (fp_line (start -1.55 29.55) (end 16.8 29.55) (layer F.CrtYd) (width 0.05))
+    (fp_line (start -1.55 -1.6) (end -1.55 29.55) (layer F.CrtYd) (width 0.05))
+    (fp_line (start 16.51 -1.33) (end -1.27 -1.33) (layer F.Fab) (width 0.1))
+    (fp_line (start 16.51 29.27) (end 16.51 -1.33) (layer F.Fab) (width 0.1))
+    (fp_line (start -1.27 29.27) (end 16.51 29.27) (layer F.Fab) (width 0.1))
+    (fp_line (start -1.27 -1.33) (end -1.27 29.27) (layer F.Fab) (width 0.1))
+    (fp_line (start 0.255 -0.27) (end 1.255 -1.27) (layer F.Fab) (width 0.1))
+    (fp_line (start 0.255 29.21) (end 0.255 -0.27) (layer F.Fab) (width 0.1))
+    (fp_line (start 14.985 29.21) (end 0.255 29.21) (layer F.Fab) (width 0.1))
+    (fp_line (start 14.985 -1.27) (end 14.985 29.21) (layer F.Fab) (width 0.1))
+    (fp_line (start 1.255 -1.27) (end 14.985 -1.27) (layer F.Fab) (width 0.1))
     (fp_text user %R (at 7.62 13.97) (layer F.Fab) hide
       (effects (font (size 1 1) (thickness 0.15)))
     )
@@ -339,10 +342,10 @@
     (fp_text value CR2025 (at -0.127 -0.254) (layer F.SilkS)
       (effects (font (size 1 1) (thickness 0.15)))
     )
-    (fp_circle (center 0 0) (end 0.1 -7.5) (layer F.SilkS) (width 0.12))
-    (fp_line (start -5 5.6) (end -5 7.9) (layer F.SilkS) (width 0.12))
-    (fp_line (start -5 7.9) (end 5 7.9) (layer F.SilkS) (width 0.12))
     (fp_line (start 5 7.9) (end 5 5.6) (layer F.SilkS) (width 0.12))
+    (fp_line (start -5 7.9) (end 5 7.9) (layer F.SilkS) (width 0.12))
+    (fp_line (start -5 5.6) (end -5 7.9) (layer F.SilkS) (width 0.12))
+    (fp_circle (center 0 0) (end 0.1 -7.5) (layer F.SilkS) (width 0.12))
     (pad 1 smd rect (at 0 8 180) (size 2.3 4) (layers F.Cu F.Paste F.Mask)
       (net 19 BC))
     (pad 2 smd rect (at 0 -8 180) (size 2.3 4) (layers F.Cu F.Paste F.Mask)
@@ -363,26 +366,26 @@
     (fp_text value "32kHz 6pF" (at -3.1115 -0.889 90) (layer B.SilkS)
       (effects (font (size 1 1) (thickness 0.15)) (justify mirror))
     )
-    (fp_line (start -0.95 1.9) (end -0.95 -4.1) (layer B.Fab) (width 0.1))
-    (fp_line (start -0.95 -4.1) (end 0.95 -4.1) (layer B.Fab) (width 0.1))
-    (fp_line (start 0.95 -4.1) (end 0.95 1.9) (layer B.Fab) (width 0.1))
-    (fp_line (start 0.95 1.9) (end -0.95 1.9) (layer B.Fab) (width 0.1))
-    (fp_line (start -0.5 1.9) (end -1.27 2.7) (layer B.Fab) (width 0.1))
-    (fp_line (start -1.27 2.7) (end -1.27 3.5) (layer B.Fab) (width 0.1))
-    (fp_line (start 0.5 1.9) (end 1.27 2.7) (layer B.Fab) (width 0.1))
-    (fp_line (start 1.27 2.7) (end 1.27 3.5) (layer B.Fab) (width 0.1))
-    (fp_line (start -1.7 2.1) (end -1.7 -4.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start -1.7 -4.5) (end 1.7 -4.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start 1.7 -4.5) (end 1.7 2.1) (layer B.SilkS) (width 0.12))
-    (fp_line (start 1.7 2.1) (end -1.7 2.1) (layer B.SilkS) (width 0.12))
-    (fp_line (start -0.5 2.1) (end -1.27 2.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start -1.27 2.5) (end -1.27 2.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start 0.5 2.1) (end 1.27 2.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start 1.27 2.5) (end 1.27 2.5) (layer B.SilkS) (width 0.12))
-    (fp_line (start -2.1 4.63) (end -2.1 -5.07) (layer B.CrtYd) (width 0.05))
-    (fp_line (start -2.1 -5.07) (end 2.1 -5.07) (layer B.CrtYd) (width 0.05))
-    (fp_line (start 2.1 -5.07) (end 2.1 4.63) (layer B.CrtYd) (width 0.05))
     (fp_line (start 2.1 4.63) (end -2.1 4.63) (layer B.CrtYd) (width 0.05))
+    (fp_line (start 2.1 -5.07) (end 2.1 4.63) (layer B.CrtYd) (width 0.05))
+    (fp_line (start -2.1 -5.07) (end 2.1 -5.07) (layer B.CrtYd) (width 0.05))
+    (fp_line (start -2.1 4.63) (end -2.1 -5.07) (layer B.CrtYd) (width 0.05))
+    (fp_line (start 1.27 2.5) (end 1.27 2.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start 0.5 2.1) (end 1.27 2.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start -1.27 2.5) (end -1.27 2.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start -0.5 2.1) (end -1.27 2.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start 1.7 2.1) (end -1.7 2.1) (layer B.SilkS) (width 0.12))
+    (fp_line (start 1.7 -4.5) (end 1.7 2.1) (layer B.SilkS) (width 0.12))
+    (fp_line (start -1.7 -4.5) (end 1.7 -4.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start -1.7 2.1) (end -1.7 -4.5) (layer B.SilkS) (width 0.12))
+    (fp_line (start 1.27 2.7) (end 1.27 3.5) (layer B.Fab) (width 0.1))
+    (fp_line (start 0.5 1.9) (end 1.27 2.7) (layer B.Fab) (width 0.1))
+    (fp_line (start -1.27 2.7) (end -1.27 3.5) (layer B.Fab) (width 0.1))
+    (fp_line (start -0.5 1.9) (end -1.27 2.7) (layer B.Fab) (width 0.1))
+    (fp_line (start 0.95 1.9) (end -0.95 1.9) (layer B.Fab) (width 0.1))
+    (fp_line (start 0.95 -4.1) (end 0.95 1.9) (layer B.Fab) (width 0.1))
+    (fp_line (start -0.95 -4.1) (end 0.95 -4.1) (layer B.Fab) (width 0.1))
+    (fp_line (start -0.95 1.9) (end -0.95 -4.1) (layer B.Fab) (width 0.1))
     (fp_text user %R (at 0 -0.3 180) (layer B.Fab)
       (effects (font (size 0.6 0.6) (thickness 0.09)) (justify mirror))
     )

kicad/nwX287.lib

@@ -1,11 +1,11 @@
 EESchema-LIBRARY Version 2.4
 #encoding utf-8
 #
-# bq4285
+# bq3285
 #
-DEF bq4285 U 0 40 Y Y 1 F N
+DEF bq3285 U 0 40 Y Y 1 F N
 F0 "U" 0 200 50 H V C CNN
-F1 "bq4285" 0 100 50 H V C CNN
+F1 "bq3285" 0 100 50 H V C CNN
 F2 "" 0 50 50 H I C CNN
 F3 "" 0 50 50 H I C CNN
 DRAW
@@ -23,8 +23,8 @@ X ~RST 18 400 -650 100 L 50 50 1 1 I
 X ~INT 19 400 -550 100 L 50 50 1 1 I
 X X1 2 -400 -150 100 R 50 50 1 1 I
 X BC 20 400 -450 100 L 50 50 1 1 I
-X ~CEI 21 400 -350 100 L 50 50 1 1 I
-X ~CEO 22 400 -250 100 L 50 50 1 1 I
+X ~RCL 21 400 -350 100 L 50 50 1 1 I
+X NC 22 400 -250 100 L 50 50 1 1 I
 X SQW 23 400 -150 100 L 50 50 1 1 I
 X VCC 24 400 -50 100 L 50 50 1 1 I
 X X2 3 -400 -250 100 R 50 50 1 1 I
@@ -37,11 +37,11 @@ X AD5 9 -400 -850 100 R 50 50 1 1 I
 ENDDRAW
 ENDDEF
 #
-# ds12887
+# bq4285
 #
-DEF ds12887 U 0 40 Y Y 1 F N
+DEF bq4285 U 0 40 Y Y 1 F N
 F0 "U" 0 200 50 H V C CNN
-F1 "ds12887" 0 100 50 H V C CNN
+F1 "bq4285" 0 100 50 H V C CNN
 F2 "" 0 50 50 H I C CNN
 F3 "" 0 50 50 H I C CNN
 DRAW
@@ -59,8 +59,8 @@ X ~RST 18 400 -650 100 L 50 50 1 1 I
 X ~INT 19 400 -550 100 L 50 50 1 1 I
 X X1 2 -400 -150 100 R 50 50 1 1 I
 X BC 20 400 -450 100 L 50 50 1 1 I
-X ~RCL 21 400 -350 100 L 50 50 1 1 I
-X NC 22 400 -250 100 L 50 50 1 1 I
+X ~CEI 21 400 -350 100 L 50 50 1 1 I
+X ~CEO 22 400 -250 100 L 50 50 1 1 I
 X SQW 23 400 -150 100 L 50 50 1 1 I
 X VCC 24 400 -50 100 L 50 50 1 1 I
 X X2 3 -400 -250 100 R 50 50 1 1 I

kicad/nwX287.sch

@@ -14,7 +14,7 @@ Comment3 ""
 Comment4 ""
 $EndDescr
 $Comp
-L nw12887:bq4285 U2
+L nwX287:bq4285 U2
 U 1 1 60A068FA
 P 3850 2300
 F 0 "U2" H 3850 2475 50  0000 C CNN
@@ -25,7 +25,7 @@ F 3 "" H 3850 2350 50  0001 C CNN
 	1    0    0    -1  
 $EndComp
 $Comp
-L nw12887:bq4285 U1
+L nwX287:bq4285 U1
 U 1 1 60A06FF2
 P 5350 2300
 F 0 "U1" H 5350 2475 50  0000 C CNN

kicad/sym-lib-table

@@ -1,3 +1,3 @@
 (sym_lib_table
-  (lib (name nw12887)(type Legacy)(uri ${KIPRJMOD}/nw12887.lib)(options "")(descr ""))
+  (lib (name nwX287)(type Legacy)(uri ${KIPRJMOD}/nwX287.lib)(options "")(descr ""))
 )