anomalous touch logger (#147)

* anomalous touch logger

* service

* add evdev

* rename

* Update userspace/files/phantom_touch_logger.service

userspace/files/phantom_touch_logger.service

@@ -0,0 +1,10 @@
+[Unit]
+After=multi-user.target
+
+[Service]
+User=comma
+Restart=no
+ExecStart=/usr/local/pyenv/shims/python -u /usr/comma/phantom_touch_logger.py
+
+[Install]
+WantedBy=multi-user.target

userspace/services.sh

@@ -25,6 +25,7 @@ systemctl enable ssh-param-watcher.service
 systemctl enable home.mount
 systemctl enable logrotate-hourly.timer
 systemctl enable set_time.service
+systemctl enable phantom_touch_logger.service
 
 # Disable some of our services
 systemctl disable serial-hostname.service

userspace/usr/comma/phantom_touch_logger.py

@@ -0,0 +1,35 @@
+#!/usr/bin/env python3
+import sys
+from collections import deque
+from evdev import InputDevice, ecodes
+
+def log(msg):
+  # TODO: keep buffer of touch events + coords and dump after log
+  print(msg, file=sys.stderr)
+
+if __name__ == "__main__":
+  touch_starts = deque([0.]*20, maxlen=20)
+
+  dev = InputDevice('/dev/input/by-path/platform-894000.i2c-event')
+  for event in dev.read_loop():
+    #print(event.type, event.code, event.value)
+
+    # TODO: consider multitouch events
+    if event.type == ecodes.EV_KEY and event.code == ecodes.BTN_TOUCH:
+      if event.value == 1:
+        touch_starts.append(event.timestamp())
+
+        avg_touch_dt = (max(touch_starts) - min(touch_starts)) / len(touch_starts)
+        avg_touch_freq = 1 / (avg_touch_dt + 0.0001)
+        if avg_touch_freq > 15:
+          log(f"Quick touch frequency {avg_touch_freq:.2f}s / {event}")
+
+        if len(touch_starts) > 2:
+          dt = (touch_starts[-1] - touch_starts[-2])
+          if dt < 0.02:
+            log(f"Quick consecutive touches {dt:.2f}s / {event}")
+      elif event.value == 0:
+        if len(touch_starts):
+          dt = event.timestamp() - touch_starts[-1]
+          if dt > 10.:
+            log(f"Touch point persisted for {dt:.2f}s / {event}")