# HDMI Pinout Mapping

This document maps the 19 HDMI pins to the multiplexer channels.

## HDMI Type A Connector Pinout
1. TMDS Data2+
2. TMDS Data2 Shield
3. TMDS Data2-
4. TMDS Data1+
5. TMDS Data1 Shield
6. TMDS Data1-
7. TMDS Data0+
8. TMDS Data0 Shield
9. TMDS Data0-
10. TMDS Clock+
11. TMDS Clock Shield
12. TMDS Clock-
13. CEC
14. Reserved (HEAC+ in 1.4)
15. SCL (DDC)
16. SDA (DDC)
17. DDC/CEC Ground
18. +5V Power
19. Hot Plug Detect (HEAC- in 1.4)

## Multiplexer Mapping (2x CD74HC4067)
We use two 16-channel muxes.

### Mux A (High Speed Data)
- Channel 0: Pin 1 (Data2+)
- Channel 1: Pin 3 (Data2-)
- Channel 2: Pin 4 (Data1+)
- Channel 3: Pin 6 (Data1-)
- Channel 4: Pin 7 (Data0+)
- Channel 5: Pin 9 (Data0-)
- Channel 6: Pin 10 (Clock+)
- Channel 7: Pin 12 (Clock-)

### Mux B (Control & Power)
- Channel 0: Pin 13 (CEC)
- Channel 1: Pin 14 (Reserved/HEAC+)
- Channel 2: Pin 15 (SCL)
- Channel 3: Pin 16 (SDA)
- Channel 4: Pin 18 (+5V)
- Channel 5: Pin 19 (HPD)

## Expected Diode Mode Values (General Guide)
- TMDS Lines (1, 3, 4, 6, 7, 9, 10, 12): 0.3V - 0.7V
- DDC Lines (15, 16): 0.5V - 0.8V
- CEC (13): 0.6V - 0.9V
- +5V (18): Usually high or varies depending on console (check for shorts!)
- HPD (19): 0.6V - 0.9V

*Note: Shields (2, 5, 8, 11) and GND (17) should be tied to common ground for the measurement.*