Show COVID-19 exposure notification statistics

Based on !390 (merged)

Displays how many unique MACs (aka phones) which send exposure notifications have been seen during the last 100 seconds.

It tries to distinguish between Apple and Google devices based on a heuristic mentioned in https://github.com/znuh/microbit-corona-scanner. The user can choose if they want the LEDs and/or the vibration motor to show newly discovered MACs / exposure notifications.

Loosely based on:

• https://github.com/kauzu/CoronaAppDetector
• https://github.com/frankrieger/CoronaAppDetectorM5StickC
• https://github.com/znuh/microbit-corona-scanner

Most of the logic resides in a plain Python script and can be modified by the user as needed.

preload/apps/exnostat/__init__.py

@@ -6,6 +6,7 @@ import display
 import color
 import buttons
 import leds
+import config
 
 DM_ADV_TYPE_FLAGS = 0x01
 DM_ADV_TYPE_16_UUID = 0x03
@@ -19,8 +20,8 @@ MODE_ON_RX = 2
 MODE_BOTH = 3
 
 seen = {}
-vib_mode = MODE_OFF
-led_mode = MODE_OFF
+vib_mode = MODE_BOTH
+led_mode = MODE_BOTH
 
 
 def parse_advertisement_data(data):
@@ -100,12 +101,13 @@ def process_scan_report(scan_report):
 
 def ble_callback(_):
     event = sys_ble.get_event()
-    prune()
-    while True:
-        scan_report = sys_ble.get_scan_report()
-        if scan_report == None:
-            return
-        process_scan_report(scan_report)
+    if event == sys_ble.EVENT_SCAN_REPORT:
+        while True:
+            scan_report = sys_ble.get_scan_report()
+            if scan_report == None:
+                break
+            process_scan_report(scan_report)
+        prune()
 
 
 def show_stats():
@@ -139,7 +141,6 @@ def show_stats():
     disp.update()
 
 
-t0 = time.time()
 last_rx_time = 0
 disp = display.open()
 v_old = 0
@@ -148,6 +149,15 @@ pause = 1
 interrupt.set_callback(interrupt.BLE, ble_callback)
 interrupt.enable_callback(interrupt.BLE)
 
+try:
+    vib_mode = int(config.get_string("exno_vib_mode"))
+except:
+    pass
+
+try:
+    led_mode = int(config.get_string("exno_led_mode"))
+except:
+    pass
 
 disp.clear()
 disp.print(" Exp Notif", posy=0, fg=color.WHITE)
@@ -158,6 +168,7 @@ disp.update()
 
 time.sleep(3)
 
+t0 = time.time()
 sys_ble.scan_start()
 
 while True:
@@ -182,8 +193,9 @@ while True:
         elif vib_mode == MODE_BOTH:
             vib_mode = MODE_OFF
             disp.print("Vib off", posy=40, fg=color.WHITE)
-
         disp.update()
+
+        config.set_string("exno_vib_mode", str(vib_mode))
         pause = 20
 
     if v & buttons.BOTTOM_LEFT:
@@ -203,8 +215,9 @@ while True:
         elif led_mode == MODE_BOTH:
             led_mode = MODE_OFF
             disp.print("LED off", posy=40, fg=color.WHITE)
-
         disp.update()
+
+        config.set_string("exno_led_mode", str(led_mode))
         pause = 20
 
     pause -= 1