fix(max86150): Use 4x averaging on chip

epicardium/modules/max86150.c

@@ -66,6 +66,8 @@ int epic_max86150_enable_sensor(
 		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_100;
 	} else if (config->ppg_sample_rate == 200) {
 		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_200;
+	} else if (config->ppg_sample_rate == 400) {
+		ppg_sample_rate = MAX86150_PPG_SAMPLERATE_400;
 	} else {
 		result = -EINVAL;
 		goto out_free;

preload/apps/spo2/__init__.py

@@ -7,7 +7,7 @@ import buttons
 class SPO2:
     def __init__(self):
         self.sensor = None
-        self.RATE = 128
+        self.RATE = 100
         self.HISTORY_MAX = self.RATE * 4
         self.history = []
         self.update_screen = 0
@@ -35,7 +35,7 @@ class SPO2:
             if self.update_screen >= self.DRAW_AFTER_SAMPLES:
                 self.draw_histogram()
 
-        self.sensor = max86150.MAX86150(callback)
+        self.sensor = max86150.MAX86150(callback=callback, sample_rate=self.RATE * 4)
         while True:
             utime.sleep(.1)
             if buttons.read(buttons.BOTTOM_RIGHT):