HDMI Pin Assignments

[biomurph]

@eyuan-creare
Hi, I am tagging you on this because I think you are making this decision.
Please pass it on if not you.

What are the desired HDMI pin assignments for this build?
We had a bit of a discussion about how to assign the twisted pairs in standard HDMI cables and how they might effect our signals.

[eyuan-creare]

Here's what Chris Brooks proposed for pin assignments on the microHDMI cable. This is from Creare's git issue:

• https://code.crearecomputing.com/hearingproducts/open-hearing-group/open-hearing-hardware/-/work_items/27

Micro-HDMI Pin	HDMI Signal	Tympan Shield Signal	Auren PCB Signal
1	Hot Plug Detect / HEAC-	GND	GND_1
2	Utility / HEAC+	3.3V	VDD_1
3	TMDS Data2+	HPL_1_OUT ("HPL_1")	SPK1+
4	TMDS Data2 Shield	GND	Not Connected
5	TMDS Data2-	HPL_1_RET ("GND_SENS_L")	SPK1-
6	TMDS Data1+	PDM_CLK	CLK_1
7	TMDS Data1 Shield	GND	Not Connected
8	TMDS Data1-	PDM_DAT	DAT_1
9	TMDS Data0+	HPR_1_OUT ("HPR_1")	SPK2+
10	TMDS Data0 Shield	GND	Not Connected
11	TMDS Data0-	HPR_1_RET ("GND_SENS_R")	SPK2-
12	TMDS Clock+	PDM_CLK1	CLK_2
13	TMDS Clock Shield	GND	Not Connected
14	TMDS Clock-	PDM_DAT1	DAT_2
15	CEC	GND	GND_2
16	DDC/CEC Ground / HEAC Shield	GND	Not Connected
17	SCL	Reserved_1 (Test Point 1)	Reserved_1 (Test Point 1)
18	SDA	Reserved_2 (Test Point 2)	Reserved_2 (Test Point 2)
19	+5V Power	3.3V	VDD_2

[biomurph]

Duly noted, Thanks!

[biomurph]

@eyuan-creare
What is the difference between GND_1, VDD_1 verses GND_2, VDD_2?

[biomurph]

@eyuan-creare
Here's a pic of the HDMI pin assignments.

[biomurph]

This was brought up in #2 and I'm moving it here.
There is a discrepancy between the different size HDMI pinouts, mentioned here
https://www.electronics-notes.com/articles/audio-video/hdmi/hdmi-pinouts-connections.php

@eyuan-creare I will use your chart at above to correlate between the Micro HDMI and the Standard HDMI so we are not crossing the streams.

[b-graybill]

Thanks @biomurph . I updated the table with the full-size pins and changed the columns so that each board is adjacent to its respective connector:

Micro-HDMI Pin	HDMI Signal	Auren PCB Signal	Tympan Shield Signal	Full-Size HDMI Pin
1	Hot Plug Detect / HEAC-	GND_1	GND	19
2	Utility / HEAC+	VDD_1	3.3V	14
3	TMDS Data2+	SPK1+	HPL_1_OUT ("HPL_1")	1
4	TMDS Data2 Shield	Not Connected	GND	2
5	TMDS Data2-	SPK1-	| HPL_1_RET ("GND_SENS_L") |	3
6	TMDS Data1+	CLK_1	PDM_CLK	4
7	TMDS Data1 Shield	Not Connected	GND	5
8	TMDS Data1-	DAT_1	PDM_DAT	6
9	TMDS Data0+	SPK2+	HPR_1_OUT ("HPR_1")	7
10	TMDS Data0 Shield	Not Connected	GND	8
11	TMDS Data0-	SPK2-	HPR_1_RET ("GND_SENS_R")	9
12	TMDS Clock+	CLK_2	PDM_CLK1	10
13	TMDS Clock Shield	Not Connected	GND	11
14	TMDS Clock-	DAT_2	PDM_DAT1	12
15	CEC	GND_2	GND	13
16	DDC/CEC Ground / HEAC Shield	Not Connected	GND	17
17	SCL	Reserved_1 (Test Point 1)	Reserved_1 (Test Point 1)	15
18	SDA	Reserved_2 (Test Point 2)	Reserved_2 (Test Point 2)	16
19	+5V Power	VDD_2	3.3V	18

[biomurph]

This is great! I will confirm while I build it up.

[biomurph]

OK, we're off to the races.
Here's the updated shcematic connector on the Auren Shield side.
I'll have the board layout for review shortly.