included pygate reference api

content/datasheets/expansionboards/pygate.md

@@ -45,3 +45,5 @@ The Pygate features a single cell Li-Ion/Li-Po charger. When the board is being
 
 * If PIC stays in bootloader mode, the [`dfu-util` update](/pytrackpysense/installation/firmware) should be performed
 
+* If `machine.callback()` gives an error, update your -py device with the `pygate` firmware.
+

content/firmwareapi/pycom/machine/pygate.md

@@ -0,0 +1,39 @@
+---
+title: "Pygate"
+aliases:
+    - firmwareapi/pycom/machine/pygate.html
+    - firmwareapi/pycom/machine/pygate.md
+    - chapter/firmwareapi/pycom/machine/pygate
+---
+
+The Pygate is an 8-channel LoRaWAN gateway. Connect a WiPy, Gpy or LoPy4 board to the Pygate and flash the Pygate firmware. See the [Pygate tutorial](/tutorials/all/pygate) to get started.
+
+## Methods
+
+#### machine.pygate\_init(buff)
+
+This function is used to initialize the Pygate
+
+- `buff`: the data contents of the gateway global config json file
+
+#### machine.pygate\_deinit()
+
+This shuts down the concentrator.
+
+#### machine.callback(trigger, handler=None, arg=None)
+
+- `trigger`: A trigger event(s) for invoking the callback function `handler`, the triggers/events are:
+
+	`machine.PYGATE_START_EVT`
+
+	`machine.PYGATE_STOP_EVT`
+
+	`machine.MP_QSTR_PYGATE_ERROR_EVT`
+
+- `handler`: The callback function to be called.  When not passed to function, any pre-registered callback will be disabled/removed.
+
+- `arg`: Optional argument to be passed to the callback function.
+
+#### machine.events()
+
+Get the Pygate events