diff --git a/main.c b/main.c
index cbe6a4f..61f37bf 100644
--- a/main.c
+++ b/main.c
@@ -144,7 +144,7 @@ int main(void) {
 
     uint8_t voltage_scale = 0;
     uint8_t time_scale = 0;
-    uint8_t rising = 1;
+    uint8_t trigger_mode = 1;
 
     while (true) {
         // calculate cpu usage
@@ -158,7 +158,8 @@ int main(void) {
         while (fifo_get(&button)) {
             switch (button) {
                 case S1: // toggle edge
-                    rising = !rising;
+                    trigger_mode++;
+                    trigger_mode %= 3;
                     break;
                 case S2: // draw
                     refresh = !refresh;
@@ -203,10 +204,16 @@ int main(void) {
         snprintf(str, sizeof(str), "CPU Load %.1f%%", usage_percent); 
         GrStringDraw(&sContext, str, /*length*/ -1, /*x*/ 0, /*y*/ HEIGHT - 10, /*opaque*/ false);
 
-        if (rising) {
-            GrStringDraw(&sContext, "^", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
-        } else {
-            GrStringDraw(&sContext, "v", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+        switch (trigger_mode) {
+            case 1:
+                GrStringDraw(&sContext, "^", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
+            case 0:
+                GrStringDraw(&sContext, "v", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
+            case 2:
+                GrStringDraw(&sContext, "-", /*length*/ -1, /*x*/ WIDTH - 10, /*y*/ 0, /*opaque*/ false);
+                break;
         }
 
         // display graph
@@ -215,7 +222,12 @@ int main(void) {
         int32_t adc_current_index;
         int32_t j;
         if (refresh) {
-            int trigger = Trigger(rising);
+            int trigger;
+            if (trigger_mode == 2) {
+                trigger = gADCBufferIndex - (WIDTH / 2); // show latest if trigger disabled
+            } else {
+                trigger = Trigger(trigger_mode);
+            }
 
             adc_current_index = trigger - (WIDTH / 2);
             for (j=0; j<LOCAL_BUF_LEN; j++) {
@@ -303,6 +315,6 @@ int Trigger(bool rising) // search for edge trigger
         }
     }
     if (x == x_stop) // for loop ran to the end
-    x = x = gADCBufferIndex - (WIDTH / 2); // reset x back to how it was initialized
+    x = gADCBufferIndex - (WIDTH / 2); // reset x back to how it was initialized
     return x;
 }