From c4f8e8bab01b79533ef703fa326f98275eaa6637 Mon Sep 17 00:00:00 2001
From: sza2 <sza2@users.noreply.github.com>
Date: Sat, 17 Apr 2021 10:34:32 +0200
Subject: [PATCH] Inittial release

---
 pc60fw.py | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 67 insertions(+)
 create mode 100644 pc60fw.py

diff --git a/pc60fw.py b/pc60fw.py
new file mode 100644
index 0000000..fa92576
--- /dev/null
+++ b/pc60fw.py
@@ -0,0 +1,67 @@
+#!/usr/bin/env python
+import sys
+import libscrc
+import bluepy
+
+stream = bytearray()
+
+class MyDelegate(bluepy.btle.DefaultDelegate):
+    def __init__(self):
+        bluepy.btle.DefaultDelegate.__init__(self)
+
+    def handleNotification(self, cHandle, data):
+        stream.extend(bytearray(data))
+        i = 0
+        while(True):
+            if(len(stream) == 0):
+                break
+            # search for sync sequence
+            idx = stream.find(b'\xaa\x55')
+            # gather more bytes if the sync sequence not found
+            if(idx < 0):
+                break
+            # check if there are enough bytes to read the message length
+            # otherwise skip and gather more bytes
+            if(len(stream) >= idx + 4):
+                length = stream[idx + 3]
+                # check whether all the bytes of the message available
+                # otherwise skip and gather more bytes
+                if(len(stream) >= idx + 4 + length):
+                    # remove the bytes from the stream prior sync
+                    # (if any - as this should not happen except in case of the firs message)
+                    del stream[0 : idx]
+                    # copy the whole message 
+                    message = stream[0 : idx + 4 + length]
+                    # the last byte of the message is a CRC8/MAXIM 
+                    # the CRC sum for the whole message (including the CRC) must be 0
+                    if(libscrc.maxim8(message) != 0):
+                        print("CRC error")
+                    # remove the sync bytes and the CRC
+                    message =  message[2 : idx + 3 + length]
+                    # remove the processed bytes from the stream
+                    del stream[0 : idx + 4 + length]
+                    # messages with 0x08 on the second spot contains values appear on the OLED display
+                    if(message[1] == 0x08):
+                        print("SpO2: %d PR: %d PI: %1.1f" % (message[3], message[4], message[6] / 10))
+                else:
+                    break
+            else:
+                break
+
+pulseoximeter = bluepy.btle.Peripheral(sys.argv[1], "random")
+
+try:
+    pulseoximeter.setDelegate(MyDelegate())
+
+    # enable notification
+    setup_data = b"\x01\x00"
+    notify = pulseoximeter.getCharacteristics(uuid='6e400003-b5a3-f393-e0a9-e50e24dcca9e')[0]
+    notify_handle = notify.getHandle() + 1
+    pulseoximeter.writeCharacteristic(notify_handle, setup_data, withResponse = True)
+
+    # wait for answer
+    while True:
+        if pulseoximeter.waitForNotifications(1.0):
+            continue
+finally:
+    pulseoximeter.disconnect()