diff --git a/main/squeeze.c b/main/squeeze.c
--- a/main/squeeze.c
+++ b/main/squeeze.c
@@ -3,12 +3,14 @@
 #include "esp_log.h"
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
-
 #include "squeeze.h"
 
-static const char *TAG = "squeeze";
 
+// Private variables
+static const char *TAG = "squeeze";
 esp_adc_cal_characteristics_t adc1_chars;
+static squeezable_t squeezables[SQUEEZABLE_MAX] = {0};
+
 
 // Private prototypes
 static void squeeze_process(void);
@@ -18,57 +20,57 @@ void squeeze_init(void)
 {
     // ADC1 chan0 is PIN1
     adc1_config_channel_atten(ADC1_CHANNEL_0, ADC_ATTEN_DB_12);
+    squeezables[SQUEEZABLE_HEART].adc_channel = ADC1_CHANNEL_0;
+    // ADC1 chan1 is GPIO2
+    adc1_config_channel_atten(ADC1_CHANNEL_1, ADC_ATTEN_DB_12);
+    squeezables[SQUEEZABLE_BRAIN].adc_channel = ADC1_CHANNEL_1;
+
     esp_adc_cal_characterize(ADC_UNIT_1, ADC_ATTEN_DB_12, ADC_WIDTH_BIT_DEFAULT, 0, &adc1_chars);
+
     xTaskCreatePinnedToCore(squeeze_process, "squeeze", 1024*2, NULL, 10, NULL, 1);
 }
 
 
-// Definitions
-#define ALPHA_FAST 0.02f
-#define ALPHA_SLOW 0.005f
-
-// Private variables
-static float reading_fast = 0.0f;
-static float reading_slow = 0.0f;
-static float delta_last = 0.0f;
-static uint8_t triggered_flag = 0;
-
 
 static void squeeze_process(void)
 {
     for(;;)
     {
-        uint32_t millivolts = esp_adc_cal_raw_to_voltage(adc1_get_raw(ADC1_CHANNEL_0), &adc1_chars);
 
-        reading_fast = (ALPHA_FAST * millivolts) + ((1.0-ALPHA_FAST) * reading_fast);
-        reading_slow = (ALPHA_SLOW * millivolts) + ((1.0-ALPHA_SLOW) * reading_slow);
-        float delta = reading_fast - reading_slow;
+        for(uint8_t i=0; i<SQUEEZABLE_MAX; i++)
+        {
+            uint32_t millivolts = esp_adc_cal_raw_to_voltage(adc1_get_raw(squeezables[i].adc_channel), &adc1_chars);
 
-        //ESP_LOGI(TAG, "ADC read %lu fast=%g slow=%g delta=%g", millivolts, reading_fast, reading_slow, delta);
+            squeezables[i].reading_fast = (ALPHA_FAST * millivolts) + ((1.0-ALPHA_FAST) * squeezables[i].reading_fast);
+            squeezables[i].reading_slow = (ALPHA_SLOW * millivolts) + ((1.0-ALPHA_SLOW) * squeezables[i].reading_slow);
+            float delta = squeezables[i].reading_fast - squeezables[i].reading_slow;
 
-        if(delta > 4.0 && delta_last < 4.0)
-        {
-            ESP_LOGI(TAG, "Trigger at delta %g", delta);
+            //ESP_LOGI(TAG, "ADC read %lu fast=%g slow=%g delta=%g", millivolts, reading_fast, reading_slow, delta);
+
+            if(delta > 4.0 && squeezables[i].delta_last < 4.0)
+            {
+                ESP_LOGI(TAG, "Trigger at delta %g", delta);
 
-            // set flag, consumed on read by squeeze_triggered()
-            triggered_flag = 1;
+                // set flag, consumed on read by squeeze_triggered()
+                squeezables[i].triggered_flag = 1;
+            }
+            squeezables[i].delta_last = delta;
         }
-        delta_last = delta;
         vTaskDelay(10 / portTICK_PERIOD_MS);
     }
 }
 
-float squeeze_value(void)
+float squeeze_value(squeezable_id_t id)
 {
-    return reading_fast;
+    return squeezables[id].reading_fast;
 }
 
-uint8_t squeeze_triggered(void)
+uint8_t squeeze_triggered(squeezable_id_t id)
 {
-    if(triggered_flag == 1)
+    if(squeezables[id].triggered_flag == 1)
     {
         // consume
-        triggered_flag = 0;
+        squeezables[id].triggered_flag = 0;
         return 1;
     }
     else