add schematic pdfs and firmware code

Code/devterm_keyboard/trackball.ino

@@ -0,0 +1,53 @@
+/*
+ * clockworkpi devterm trackball 
+ */
+#include "keys_io_map.h"
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include <USBComposite.h>
+
+#include "trackball.h"
+
+
+int btn_state;
+int btn_read_state;
+unsigned long btn_current_action_time;
+unsigned long btn_last_action_time;
+
+// mouse move
+int x_move, y_move;
+Direction x_direction(LEFT_PIN, RIGHT_PIN);
+Direction y_direction(UP_PIN, DOWN_PIN);
+
+void trackball_task(DEVTERM*dv) {
+  btn_read_state = digitalRead(BTN_PIN);
+  
+  if(btn_read_state != btn_state) {
+    btn_current_action_time = millis();
+    if(btn_current_action_time - btn_last_action_time > BOUNCE_INTERVAL) {
+      btn_state = btn_read_state;
+      btn_last_action_time = btn_current_action_time;
+      
+      if(btn_state == HIGH) {
+        dv->Mouse->release();
+      } else {
+        dv->Mouse->press();
+      }
+    }
+  }
+
+  x_move = x_direction.read_action();
+  y_move = y_direction.read_action();
+  if(x_move != 0 || y_move != 0) {
+    dv->Mouse->move(x_move, y_move, 0);
+  }
+  
+}
+
+
+void trackball_init(DEVTERM*){
+  pinMode(BTN_PIN,INPUT);
+}