PI2Media PI2AES
Hardware Reference Manual – P0.1 - 3/27/2019
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Table of Contents
1 Warranty ......................................................................................................................................................................................... 3
2 Operating Specifications ................................................................................................................................................................. 4
2.1 PI2AES 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 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 Power .............................................................................................................................................................................. 11
6.1 Overview ............................................................................................................................................................................... 11
7 PI2AES 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
8.4 P2 - I2S Expansion Header ................................................................................................................................................... 16
8.1 P3 – XLR Balanced Output .................................................................................................................................................... 17
8.2 P4 – I2S Over HDMI .............................................................................................................................................................. 17
8.3 U9 – Combo RCA/Opto Transmitter ...................................................................................................................................... 18
8.4 D1 – Triple LED ..................................................................................................................................................................... 18
9 Document Revisions ..................................................................................................................................................................... 19
10 Errata.......................................................................................................................................................................................... 20
10.1 Overview ............................................................................................................................................................................. 20
List of Tables
Table 1 – PI2AES Operating Specifications ....................................................................................................................................... 4
Table 2 – PI2AES I2C Bus Devices ................................................................................................................................................... 7
Table 3 – RPi to WM8804 Connections ............................................................................................................................................. 8
Table 4 – CPU GPIO Pin Assignments ............................................................................................................................................ 10
Table 5 – I2S Expansion Header Pinout .......................................................................................................................................... 17
Table 6 – I2S Over HDMI Pinout ...................................................................................................................................................... 18
Table 7 – Document Revisions ........................................................................................................................................................ 19
List of Figures
Figure 1 – PI2AES Block Diagram ..................................................................................................................................................... 6
Figure 2 – PI2AES Power, Simplified Block Diagram ....................................................................................................................... 11
Figure 3 – PI2AES Top View ........................................................................................................................................................... 14
Figure 4 – PI2AES Front View (shown mounted on Raspberry Pi) ................................................................................................... 15
Figure 5 – PI2AES Side View (shown mounted on Raspberry Pi) .................................................................................................... 16
