From 6ad116fe1c17400f918b41e4eb5627c888774488 Mon Sep 17 00:00:00 2001
From: Andrey Pokhilko <apc4@ya.ru>
Date: Wed, 14 Aug 2019 11:04:29 +0300
Subject: [PATCH] Change button callback into 3-state

---
 docs/MoveHub.md        | 9 ++++++++-
 pylgbst/peripherals.py | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/docs/MoveHub.md b/docs/MoveHub.md
index 3047d9e..ed855a5 100644
--- a/docs/MoveHub.md
+++ b/docs/MoveHub.md
@@ -33,4 +33,11 @@ def callback(is_pressed):
 
 hub = MoveHub()
 hub.button.subscribe(callback)
-```
\ No newline at end of file
+```
+
+The state for button has 3 possible values: 
+- `0` - not released
+- `1` - pressed
+- `2` - pressed
+
+It is for now unknown why Hub always issues notification with `1` and immediately with `2`, after button is pressed.
\ No newline at end of file
diff --git a/pylgbst/peripherals.py b/pylgbst/peripherals.py
index 834adda..db80808 100644
--- a/pylgbst/peripherals.py
+++ b/pylgbst/peripherals.py
@@ -660,4 +660,4 @@ class Button(Peripheral):
         :type msg: MsgHubProperties
         """
         if msg.property == MsgHubProperties.BUTTON and msg.operation == MsgHubProperties.UPSTREAM_UPDATE:
-            self._notify_subscribers(bool(usbyte(msg.parameters, 0)))
+            self._notify_subscribers(usbyte(msg.parameters, 0))