From e2e8f5f5a95ff25f0a25299a758c53cef5ec40fb Mon Sep 17 00:00:00 2001
From: Daniel Hoffend <dh@dotlan.net>
Date: Fri, 23 Aug 2019 19:45:22 +0200
Subject: [PATCH] feat(ecg) add ecg application
---
preload/apps/ecg/__init__.py | 242 +++++++++++++++++++++++++++++++++
preload/apps/ecg/metadata.json | 1 +
2 files changed, 243 insertions(+)
create mode 100644 preload/apps/ecg/__init__.py
create mode 100644 preload/apps/ecg/metadata.json
diff --git a/preload/apps/ecg/__init__.py b/preload/apps/ecg/__init__.py
new file mode 100644
index 000000000..ccc38843d
--- /dev/null
+++ b/preload/apps/ecg/__init__.py
@@ -0,0 +1,242 @@
+import os
+import display
+import utime
+import buttons
+import max30001
+import math
+import struct
+
+WIDTH = 160
+HEIGHT = 80
+OFFSET = 50
+ECG_RATE = 128
+HISTORY_MAX = ECG_RATE * 2
+DRAW_AFTER_SAMPLES = 5
+SCALE_FACTOR = 30
+MODE_USB = "USB"
+MODE_FINGER = "Finger"
+FILEBUFFERBLOCK = 4096
+COLOR_BACKGROUND = [0, 0, 0]
+COLOR_LINE = [255, 255, 255]
+COLOR_TEXT = [255, 255, 255]
+COLOR_MODE_FINGER = [0, 255, 0]
+COLOR_MODE_USB = [0, 0, 255]
+COLOR_WRITE_FG = [255, 255, 255]
+COLOR_WRITE_BG = [255, 0, 0]
+
+current_mode = MODE_FINGER
+history = []
+filebuffer = bytearray()
+write = 0
+bias = True
+update_screen = 0
+pause_screen = 0
+sensor = 0
+disp = display.open()
+
+
+def callback_ecg(datasets):
+ global update_screen, history, filebuffer, write
+ if len(datasets) > 0:
+ for value in datasets:
+ history.append(value)
+ update_screen += len(datasets)
+ if len(history) > HISTORY_MAX:
+ r = len(history) - HISTORY_MAX
+ for i in range(r):
+ history.pop(0)
+
+ # buffer for writes
+ if write > 0:
+ if len(datasets) > 0:
+ for value in datasets:
+ filebuffer.extend(struct.pack("h", value))
+ if len(filebuffer) >= FILEBUFFERBLOCK:
+ write_filebuffer()
+
+ # don't update on every callback
+ if update_screen >= DRAW_AFTER_SAMPLES:
+ # print("history: %i, filebuffer: %i" % (len(history), len(filebuffer)))
+ draw_histogram()
+ update_screen = 0
+
+
+def write_filebuffer():
+ global write, filebuffer
+ # write to file
+ chars = ""
+ lt = utime.localtime(write)
+ filename = "/ecg-%04d-%02d-%02d_%02d%02d%02d.log" % (
+ lt[0],
+ lt[1],
+ lt[2],
+ lt[3],
+ lt[4],
+ lt[5],
+ )
+
+ # write stuff to disk
+ # print("Write %i bytes to %s" % (len(filebuffer), filename))
+ try:
+ f = open(filename, "ab")
+ f.write(filebuffer)
+ f.close()
+ except OSError as e:
+ print("Please check the file or filesystem", e)
+ write = 0
+ pause_screen = -1
+ disp.clear(COLOR_BACKGROUND)
+ disp.print("IO Error", posy=0, fg=COLOR_TEXT)
+ disp.print("Please check", posy=20, fg=COLOR_TEXT)
+ disp.print("your", posy=40, fg=COLOR_TEXT)
+ disp.print("filesystem", posy=60, fg=COLOR_TEXT)
+ disp.update()
+ close_sensor()
+ except:
+ print("Unexpected error, stop writeing logfile")
+ write = 0
+
+ filebuffer = bytearray()
+ return
+
+
+def open_sensor():
+ global sensor
+ sensor = max30001.MAX30001(
+ usb=(False if current_mode == MODE_FINGER else True),
+ bias=bias,
+ sample_rate=ECG_RATE,
+ callback=callback_ecg,
+ )
+
+
+def close_sensor():
+ global sensor
+ sensor.close()
+
+
+def toggle_mode():
+ global current_mode
+ close_sensor()
+ current_mode = MODE_USB if current_mode == MODE_FINGER else MODE_FINGER
+ open_sensor()
+
+
+def toggle_bias():
+ global bias
+ close_sensor()
+ bias = False if bias == True else True
+ open_sensor()
+ return
+
+
+def toggle_write():
+ global write, disp, pause_screen
+ pause_screen = utime.time_ms() + 1000
+ disp.clear(COLOR_BACKGROUND)
+ if write > 0:
+ write_filebuffer()
+ write = 0
+ disp.print("Stop", posx=50, posy=20, fg=COLOR_TEXT)
+ disp.print("logging", posx=30, posy=40, fg=COLOR_TEXT)
+ else:
+ filebuffer = bytearray()
+ write = utime.time()
+ disp.print("Start", posx=45, posy=20, fg=COLOR_TEXT)
+ disp.print("logging", posx=30, posy=40, fg=COLOR_TEXT)
+
+ disp.update()
+ return
+
+
+def draw_histogram():
+ global disp, history, current_mode, bias, write, pause_screen
+
+ # skip rendering due to message beeing shown
+ if pause_screen == -1:
+ return
+ elif pause_screen > 0:
+ t = utime.time_ms()
+ if t > pause_screen:
+ pause_screen = 0
+ else:
+ return
+
+ disp.clear(COLOR_BACKGROUND)
+
+ # get max value and calc scale
+ value_max = 0
+ for value in history:
+ if abs(value) > value_max:
+ value_max = abs(value)
+ scale = SCALE_FACTOR / (value_max if value_max > 0 else 1)
+
+ # draw histogram
+ old = False
+ x = 0
+ samples = len(history)
+ for i, value in enumerate(history):
+ if old == False:
+ old = (x, int(value * scale) + OFFSET)
+ x += 1
+ continue
+ elif i > samples - WIDTH:
+ disp.line(old[0], old[1], x, int(value * scale) + OFFSET, col=COLOR_LINE)
+ old = (x, int(value * scale) + OFFSET)
+ x += 1
+
+ # draw text: mode/bias/write
+ disp.print(
+ current_mode + ("+Bias" if bias else ""),
+ posx=0,
+ posy=0,
+ fg=(COLOR_MODE_FINGER if current_mode == MODE_FINGER else COLOR_MODE_USB),
+ )
+
+ # announce writing ecg log
+ if write > 0:
+ t = utime.time()
+ if write > 0 and t % 2 == 0:
+ disp.print("LOG", posx=0, posy=60, fg=COLOR_WRITE_FG, bg=COLOR_WRITE_BG)
+
+ disp.update()
+
+
+def main():
+ # show button layout
+ disp.clear(COLOR_BACKGROUND)
+ disp.print(" BUTTONS ", posx=0, posy=0, fg=COLOR_TEXT)
+ disp.print("Finger/USB>", posx=0, posy=20, fg=COLOR_MODE_FINGER)
+ disp.print(" Bias >", posx=0, posy=40, fg=COLOR_MODE_USB)
+ disp.print("< Write Log", posx=0, posy=60, fg=COLOR_WRITE_BG)
+ disp.update()
+ utime.sleep(3)
+
+ # start ecg
+ open_sensor()
+ while True:
+ button_pressed = False
+ while True:
+ v = buttons.read(
+ buttons.BOTTOM_LEFT | buttons.BOTTOM_RIGHT | buttons.TOP_RIGHT
+ )
+ if v == 0:
+ button_pressed = False
+
+ if not button_pressed and v & buttons.BOTTOM_LEFT != 0:
+ button_pressed = True
+ toggle_write()
+
+ elif not button_pressed and v & buttons.BOTTOM_RIGHT != 0:
+ button_pressed = True
+ toggle_bias()
+
+ elif not button_pressed and v & buttons.TOP_RIGHT != 0:
+ button_pressed = True
+ toggle_mode()
+
+ pass
+
+
+if __name__ == "__main__":
+ main()
diff --git a/preload/apps/ecg/metadata.json b/preload/apps/ecg/metadata.json
new file mode 100644
index 000000000..8c553a32e
--- /dev/null
+++ b/preload/apps/ecg/metadata.json
@@ -0,0 +1 @@
+{"name":"ECG","description":"A simple ecg monitor which displays the heart rate and allows you to switch between usb and finger reader.","category":"hardware","author":"griffon","revision":1}
--
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