M5: added opto-isolators

m5stack/README.md

@@ -1,16 +1,16 @@
 # M5Stack Wiegand Emulator
 
-RP2040 _M5 Stack_ module to emulate a Wiegand reader:
+RP2040 _M5Stack_ module to emulate a Wiegand reader:
 
 - Emulates a single Wiegand-26 card reader/keypad with an LED. 
-- Implements the M5 stack serial interface.
+- Implements the M5Stack serial interface.
 - Intended for use with an M5 _base_ module but can optionally be powered via the external connector
   for standalone use.
 
 ## Raison d'être
 
-Mostly because I got tired of digging out a breadboard and trying to remember how it all worked every time
-I needed to test a Wiegand interface :-).
+Mostly to avoid having to dig out a breadboard and figure how it worked all over again every time I needed
+to test a Wiegand interface.
 
 ## Status
 
@@ -22,4 +22,5 @@ I needed to test a Wiegand interface :-).
 
 ## References
 
-1. [WaveShare RP2040-Tiny](https://www.waveshare.com/wiki/RP2040-Tiny)
+1. [M5Stack](https://m5stack.com)
+2. [WaveShare RP2040-Tiny](https://www.waveshare.com/wiki/RP2040-Tiny)

m5stack/TODO.md

@@ -2,15 +2,19 @@
 
 ## Schematic
 - [ ] WaveShare Tiny library part
+      - [ ] Move 5V and 3V3 to top
+      - [ ] Move GND to bottom
+
 - [ ] Opto-isolated I/O
-- [ ] Level shifters
+      - [ ] Check current
+      - https://forums.raspberrypi.com/viewtopic.php?t=280562
 - [ ] MOVs
 - [ ] Power:
       - [ ] M5 bus + external for opto-isolators
       - [ ] M5 bus only
-      - [ ] external + isolated from M5 bus
+      - (?) external + isolated from M5 bus
 - [ ] 12V to 5V conversion
-- (?) 5V TX/RX for external UART
+- (?) USB mounting holes
 
 ## PCB
 

m5stack/kicad/library/uhppoted.kicad_sym

@@ -1,4 +1,61 @@
 (kicad_symbol_lib (version 20220914) (generator kicad_symbol_editor)
+  (symbol "MOV" (pin_numbers hide) (pin_names (offset 0)) (in_bom yes) (on_board yes)
+    (property "Reference" "V" (at -1.905 0 90)
+      (effects (font (size 1.27 1.27)))
+    )
+    (property "Value" "MOV" (at 1.905 0 90)
+      (effects (font (size 1.27 1.27)))
+    )
+    (property "Footprint" "" (at 1.27 -5.08 0)
+      (effects (font (size 1.27 1.27)) (justify left) hide)
+    )
+    (property "Datasheet" "~" (at 0 0 0)
+      (effects (font (size 1.27 1.27)) hide)
+    )
+    (property "ki_keywords" "resettable fuse PTC PPTC polyfuse polyswitch" (at 0 0 0)
+      (effects (font (size 1.27 1.27)) hide)
+    )
+    (property "ki_description" "Resettable fuse, polymeric positive temperature coefficient, small symbol" (at 0 0 0)
+      (effects (font (size 1.27 1.27)) hide)
+    )
+    (property "ki_fp_filters" "*polyfuse* *PTC*" (at 0 0 0)
+      (effects (font (size 1.27 1.27)) hide)
+    )
+    (symbol "MOV_0_1"
+      (rectangle (start -0.508 1.27) (end 0.508 -1.27)
+        (stroke (width 0) (type default))
+        (fill (type none))
+      )
+      (polyline
+        (pts
+          (xy 0 2.54)
+          (xy 0 -2.54)
+        )
+        (stroke (width 0) (type default))
+        (fill (type none))
+      )
+      (polyline
+        (pts
+          (xy -1.016 1.27)
+          (xy -1.016 0.762)
+          (xy 1.016 -0.762)
+          (xy 1.016 -1.27)
+        )
+        (stroke (width 0) (type default))
+        (fill (type none))
+      )
+    )
+    (symbol "MOV_1_1"
+      (pin passive line (at 0 2.54 270) (length 0.635)
+        (name "~" (effects (font (size 1.27 1.27))))
+        (number "1" (effects (font (size 1.27 1.27))))
+      )
+      (pin passive line (at 0 -2.54 90) (length 0.635)
+        (name "~" (effects (font (size 1.27 1.27))))
+        (number "2" (effects (font (size 1.27 1.27))))
+      )
+    )
+  )
   (symbol "WaveShare_RP2040-Tiny" (in_bom yes) (on_board yes)
     (property "Reference" "U" (at -10.16 13.97 0)
       (effects (font (size 1.27 1.27)))