Gigabit PoE Shield
==================

The Gigabit PoE Shield is a 10/100/1000 Mb/s Ethernet shield with 802.3af Power-over-Ethernet for OpenMV Cams that have an on-board Ethernet PHY. One cable to a PoE switch carries both power and the network link.

.. image:: ../gigabit-poe-shield-hero.jpg
    :alt: Gigabit PoE Shield
    :width: 400px
    :align: center

For full datasheet, photos, and ordering see the
`Gigabit PoE Shield product page <https://openmv.io/products/gigabit-poe-shield>`_.

.. note::

   Supported only on the OpenMV Cam RT1062 and N6.

Highlights
----------

* 10/100/1000 Mb/s Gigabit Ethernet with IEEE 802.3af PoE
* Up to ~6 W to the camera via 5.6 V VIN
* 1500 V isolated design — stacks with dual-header shields via on-board OR'ing diode

Pinout
------

.. image:: ../pinout-gigabit-poe-shield.png
    :alt: Gigabit PoE Shield Pinout
    :width: 700px

Pin reference
-------------

10/100 Mb/s only uses the MDI TX and MDI RX pairs (Pairs A and B).
Gigabit (1000BASE-T) is bidirectional on all four pairs A/B/C/D, so
the MDI TX ± and MDI RX ± lines double as Pair A and Pair B at gigabit
speeds, and Pairs C and D carry the additional gigabit-only pairs.

.. csv-table::
   :header: "Pin", "Function"
   :widths: 22, 78

   "MDI LED",          "PHY link / activity LED line"
   "MDI TX P / DA P",  "Pair A positive — MDI TX+ at 10/100, BI_DA+ at gigabit"
   "MDI TX N / DA N",  "Pair A negative — MDI TX− at 10/100, BI_DA− at gigabit"
   "MDI RX P / DB P",  "Pair B positive — MDI RX+ at 10/100, BI_DB+ at gigabit"
   "MDI RX N / DB N",  "Pair B negative — MDI RX− at 10/100, BI_DB− at gigabit"
   "DC P",             "Pair C positive (BI_DC+) — gigabit only"
   "DC N",             "Pair C negative (BI_DC−) — gigabit only"
   "DD P",             "Pair D positive (BI_DD+) — gigabit only"
   "DD N",             "Pair D negative (BI_DD−) — gigabit only"
   "VIN out",          "5.6 V at up to ~1 A from the on-board PoE regulator (powers the camera)"
   "3.3V rail",        "Powers the shield's on-board electronics"
   "GND rail",         "Common ground"

.. note::

   The DC and DD pairs are tied to the camera through 0-ohm resistors
   on the back of the shield. Remove them to free P15–P18 (the
   gigabit-only pins on cams like the OpenMV N6) for unrelated use —
   the shield then drops to 10/100 Ethernet since the gigabit pairs
   are no longer connected.

Usage
-----

When the shield is connected to a PoE switch, the camera's gigabit
PHY appears as a :class:`network.LAN` interface. DHCP runs
automatically once the link comes up::

    import network
    import time

    lan = network.LAN()
    lan.active(True)
    while not lan.isconnected():
        time.sleep(1)
    print("Ethernet IP:", lan.ipconfig("addr4")[0])