rename file to wobble

README.md

@@ -7,3 +7,24 @@ Perhaps useful if you have a stationary bike of some kind and want to
 put the vital statistics on a big screen instead of on your handlebar.
 
 ![screenshot](20221209_22h46m07s_grim.png)
+
+## How to use
+
+First you need to identify bluetooth address of your bike sensor(s).
+Spin the wheel to wake it up, then run
+
+```sh
+$ bluetoothctl scan on
+Discovery started
+[CHG] Controller 24:FD:52:00:ED:F1 Discovering: yes
+[NEW] Device C2:35:5D:F2:F4:0F  Giant Combo
+[CHG] Device 98:06:3A:15:B7:BA RSSI: -82
+^C
+$ bluetoothctl connect C2:35:5D:F2:F4:0F
+```
+
+Now you can start the app
+
+```sh
+$ python wobble.py C2:35:5D:F2:F4:0F
+``` 

wobble.py

@@ -1,11 +1,12 @@
 import  BLE_GATT
 from gi.repository import GLib
+
 import pdb
 import struct
 
 import sys
 import time
-from datetime import datetime
+from datetime import datetime, timedelta
 import os
 
 import pygame
@@ -13,8 +14,6 @@ import pygame.freetype
 from pygame.locals import *
 
 class CadenceListener:
-    csc_feature = '00002a5c-0000-1000-8000-00805F9B34FB' 
-
     prevCtime = 0
     prevWtime = 0
     prevWrevs = 0
@@ -22,7 +21,8 @@ class CadenceListener:
     wheelSpeed = 0
     crankSpeed = 0
     crankSpeedMax = 120
-    startTime = None
+    elapsedTime = None
+    firstMessage = True
 
     def getWheelSpeed(self):
         return self.wheelSpeed
@@ -35,13 +35,13 @@ class CadenceListener:
             offset = offset + 6
         if flags & 2:
             crankRevolutions,crankTime = struct.unpack('<HH', bytes(value)[offset:offset+4])        
-        # print(wheelrevs, wheeltime, crankrevs, cranktime)
-        if(not self.startTime):
+
+        if(self.firstMessage):
             self.prevCtime = crankTime
             self.prevWtime = wheelTime
             self.prevCrevs = crankRevolutions
             self.prevWrevs = wheelRevolutions
-            self.startTime = datetime.now()
+            self.firstMessage = False
             return
         
         # handle wraparound
@@ -62,16 +62,17 @@ class CadenceListener:
             self.prevCrevs = crankRevolutions
 
         if(wheelTime > self.prevWtime):
-            revs = ((wheelRevolutions - self.prevWrevs) /
-                    float(wheelTime - self.prevWtime))
+            millis = float(wheelTime - self.prevWtime)
+            self.rolling = True
+            revs = (wheelRevolutions - self.prevWrevs) / millis
+
             self.wheelSpeed = revs * 2205 * 3600 / 1024.0
-            print("wheel",
-                  (float(wheelTime - self.prevWtime)),
-                  self.wheelSpeed)
+            print("wheel", millis, self.wheelSpeed)
             self.prevWtime = wheelTime
             self.prevWrevs = wheelRevolutions
+            self.elapsedTime = (self.elapsedTime or 0) + (millis / 1024.0)
 
-class Biscuit:
+class Wobble:
     listener = CadenceListener()
 
     def __init__(self):
@@ -95,8 +96,8 @@ class Biscuit:
                             (scale/16,scale + 20),
                             "{: 5.1f} rpm".format(self.listener.crankSpeed),
                             (0,255,0))
-        if self.listener.startTime !=  None:
-            runTime = datetime.now() - self.listener.startTime
+        if self.listener.elapsedTime !=  None:
+            runTime = timedelta(seconds=self.listener.elapsedTime)
             timelabel = str(runTime)[0:9]
         else:
             timelabel = datetime.now().strftime("%H:%M:%S")
@@ -111,41 +112,43 @@ class Biscuit:
         pygame.display.flip()
 
 
-
-bike_address = 'C2:35:5D:F2:F4:0F'
-bike = BLE_GATT.Central(bike_address)
+bike = BLE_GATT.Central(sys.argv[1])
 bike.connect()
-app = Biscuit()
+app = Wobble()
 
 csc_measurement = '00002a5b-0000-1000-8000-00805F9B34FB' 
 bike.on_value_change(csc_measurement, app.listener.process)
 
 running = True
+
+def handle_pygame_event(event):
+    if event.type == pygame.QUIT:
+        running = False
+    if event.type == pygame.KEYUP and event.key == pygame.K_q:
+        running = False
+    if event.type == pygame.KEYUP and event.key == pygame.K_SPACE:
+        if app.listener.startTime == None:
+            app.listener.startTime = datetime.now()
+        else:
+            app.listener.startTime = None
+    if event.type == pygame.VIDEORESIZE:
+        app.width = event.w
+        app.height = event.h
+        app.font = None
+
+def on_timer():
+    handle_pygame_event(pygame.event.poll())
+    app.on_update()
+    return True
+    
+
+GLib.timeout_add(100, on_timer)
+    
 try:
     # Time to go live
-    context = bike.mainloop.get_context()
-
     print("Listening for events...")
-    while running:
-        time.sleep(0.1)
-        context.iteration(False)
-        for event in pygame.event.get():
-            if event.type == pygame.QUIT:
-                running = False
-            if event.type == pygame.KEYUP and event.key == pygame.K_q:
-                running = False
-            if event.type == pygame.KEYUP and event.key == pygame.K_SPACE:
-                if app.listener.startTime == None:
-                    app.listener.startTime = datetime.now()
-                else:
-                    app.listener.startTime = None
-            if event.type == pygame.VIDEORESIZE:
-                app.width = event.w
-                app.height = event.h
-                app.font = None
+    bike.mainloop.run()
 
-        app.on_update()
-    
 finally:
     pygame.quit()