test-sinclair: Note on optocoupling and negation

diff --git a/test-sinclair/README b/test-sinclair/README
index 80095ed933017f7b29babfcc709d75c60b97665b..cc38070209590977c0c1bde8ea03f2582ad98cf4 100644 (file)
--- a/test-sinclair/README
+++ b/test-sinclair/README
@@ -24,9 +24,9 @@ BluePill LED          | PC13           GND |
                        | PB0           PA11 |
                        | PB1           PA10 |  RXD1 - debugging console
                        | PB10           PA9 |  TXD1 - debugging console
-                       | PB11           PA8 |  IR remote control
-                       | RESET         PB15 |  MOSI2 - LED driver data input
+                       | PB11           PA8 |  IR remote control output (via optocoupler, negated)
+                       | RESET         PB15 |  MOSI2 - LED driver data input (via optocoupler, negated)
                        | 3.3 V         PB14 |  MISO2 - unused
-                       | GND           PB13 |  SCK2 - LED driver clock
+                       | GND           PB13 |  SCK2 - LED driver clock (via optocoupler, negated)
                        | GND           PB12 |  SS2 - unused
                        +--------------------+