add schematic pdfs and firmware code

Code/devterm_keyboard/trackball.h

@@ -0,0 +1,67 @@
+#ifndef TRACKBALL_H
+#define TRACKBALL_H
+
+#include "devterm.h"
+
+#include "keys_io_map.h"
+
+#define BOUNCE_INTERVAL       30
+#define BASE_MOVE_PIXELS      5
+#define EXPONENTIAL_BOUND     15
+#define EXPONENTIAL_BASE      1.2
+
+#define BTN_PIN               KEY0
+#define RIGHT_PIN             HO3
+#define LEFT_PIN              HO1
+#define DOWN_PIN              HO4
+#define UP_PIN                HO2
+
+
+
+class Direction {
+  public:
+    Direction(int pin1, int pin2) {
+      this->pins[0] = pin1;
+      this->pins[1] = pin2;
+      pinMode(this->pins[0], INPUT);
+      pinMode(this->pins[1], INPUT);
+    };
+    
+    int read_action() {
+      for(int i = 0; i < 2; ++i) {
+        this->current_actions[i] = digitalRead(this->pins[i]);
+        this->current_action_times[i] = millis();
+        if(this->current_actions[i] != this->last_actions[i]) {
+          this->last_actions[i] = this->current_actions[i];
+          exponential = (EXPONENTIAL_BOUND - (this->current_action_times[i] - this->last_action_times[i]));
+          exponential = (exponential > 0) ? exponential : 1;
+          move_multiply = EXPONENTIAL_BASE;
+          for(int i = 0; i < exponential; ++i) {
+            move_multiply *= EXPONENTIAL_BASE;
+          }
+          this->last_action_times[i] = this->current_action_times[i];
+          if(i == 0) {
+            return (-1) * BASE_MOVE_PIXELS * move_multiply;
+          } else {
+            return BASE_MOVE_PIXELS * move_multiply;
+          }
+        }
+      }
+      return 0;
+    };
+    
+  private:
+    int           pins[2];
+    int           current_actions[2];
+    int           last_actions[2];
+    int           exponential;
+    double        move_multiply;
+    unsigned long current_action_times[2];
+    unsigned long last_action_times[2];
+};
+
+void trackball_init(DEVTERM*);
+void trackball_task(DEVTERM*);
+
+
+#endif