Pi 2 Design – PI2AES 2.0 2.0 Hardware Reference Manual – P1.0 - 4/19/2023
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Table of Contents
1 Warranty......................................................................................................................................................................................... 3
2 Operating Specifications ................................................................................................................................................................. 4
2.1 PI2AES 2.0 Operating specifications ....................................................................................................................................... 4
3 Overview ........................................................................................................................................................................................ 5
3.1 Introduction ............................................................................................................................................................................. 5
3.2 Block Diagram......................................................................................................................................................................... 5
4 On-Board Devices .......................................................................................................................................................................... 7
4.1 Overview ................................................................................................................................................................................. 7
4.1 PI2AES 2.0 I2C Bus Devices................................................................................................................................................... 7
4.1 WM8804 SPDIF Transmitter.................................................................................................................................................... 7
4.1.1 WM8804 SPDIF Transmitter Notes .................................................................................................................................. 8
4.2 Dual High Resolution NDK Clocks........................................................................................................................................... 8
4.3 RS-422 Differential Transmitter ............................................................................................................................................... 8
4.4 I2S Parallel Buffer ................................................................................................................................................................... 8
4.5 I2S Differential Driver .............................................................................................................................................................. 8
4.6 Audio Data Rate and Power LED’s.......................................................................................................................................... 8
5 RPi GPIO........................................................................................................................................................................................ 9
5.1 Overview ................................................................................................................................................................................. 9
5.1.1 RPi GPIO Notes............................................................................................................................................................. 10
6 PI2AES 2.0 Power........................................................................................................................................................................ 11
6.1 Overview ............................................................................................................................................................................... 11
7 PI2AES 2.0 Software .................................................................................................................................................................... 12
7.1 Overview ............................................................................................................................................................................... 12
8 Top Side Connectors.................................................................................................................................................................... 13
8.1 Overview ............................................................................................................................................................................... 13
8.2 J1 – DC Jack......................................................................................................................................................................... 16
8.3 P1 – 40-Pin GPIO Header ..................................................................................................................................................... 16
8.1 P3 – XLR Balanced Output.................................................................................................................................................... 16
8.2 P4 – I2S Over HDMI.............................................................................................................................................................. 16
8.3 U9 – Combo RCA/Opto Transmitter ...................................................................................................................................... 17
8.4 D1 – Status LEDs.................................................................................................................................................................. 17
9 Document Revisions..................................................................................................................................................................... 18
10 Errata.......................................................................................................................................................................................... 19
10.1 Overview ............................................................................................................................................................................. 19
List of Tables
Table 1 – PI2AES 2.0 Operating Specifications ................................................................................................................................. 4
Table 2 – PI2AES 2.0 I2C Bus Devices ............................................................................................................................................. 7
Table 3 – RPi to WM8804 Connections ............................................................................................................................................. 8
Table 4 – CPU GPIO Pin Assignments............................................................................................................................................ 10
Table 5 – I2S Over HDMI Pinout...................................................................................................................................................... 17
Table 6 – Document Revisions ........................................................................................................................................................ 18
List of Figures
Figure 1 – PI2AES 2.0 Block Diagram ............................................................................................................................................... 6
Figure 2 – PI2AES 2.0 Power, Simplified Block Diagram ................................................................................................................. 11
Figure 3 – PI2AES 2.0 Top View ..................................................................................................................................................... 15
Figure 4 – PI2AES 2.0 Front View (shown mounted on Raspberry Pi 4) .......................................................................................... 15
Figure 5 – PI2AES 2.0 Side View (shown mounted on Raspberry Pi 4) ........................................................................................... 16
