single-page flash storage

5 files changed, 82 insertions, 9 deletions

diff --git a/include/app.h b/include/app.h
index ed946d5..c26c131 100644
--- a/include/app.h
+++ b/include/app.h
@@ -43,7 +43,7 @@
 
 /******************************************************************************
  Button indexing is as follows - numbers in brackets do not correspond to real
-buttons, but can be harmessly sent in hal_set_led.
+ buttons, but can be harmessly sent in hal_set_led.
  
  (90)91 92 93 94 95 96 97 98 (99)
  .......
@@ -92,6 +92,40 @@ void hal_send_midi(u8 port, u8 status, u8 data1, u8 data2);
  */
 void hal_send_sysex(u8 port, const u8* data, u16 length);
 
+/**
+ * Read some data from flash.
+ *
+ * Flash storage is in a single block, currently corresponding to one page.
+ * The block is always USER_AREA_SIZE bytes long. You can read/write any bytes
+ * within it - you do not need to worry about paging, that's handled by the HAL.
+ *
+ * The block size may increase to span multiple pages in future :)
+ *
+ * @param offset - how far into the USER_AREA_SIZE byte block to start reading
+ * @param data - buffer to receive data (must be at least length bytes long)
+ * @param length - bytes to read
+ *
+ * Attempts to read beyond the end of the block will fail silently.
+ *
+ * Note that your first ever read from a new device will contain 0xFF's until
+ * you overwrite them.
+ */
+void hal_read_flash(u32 offset, u8 *data, u32 length);
+
+/**
+ * Write data to flash
+ *
+ * Do take care to avoid thrashing it, as you can wear it out with excessive
+ * writes. The HAL does not currently do anything clever to mitigate this.
+ *
+ * @param offset - how far into the USER_AREA_SIZE byte block to start writing
+ * @param data - buffer to write (must be at least length bytes long)
+ * @param length - bytes to write
+ *
+ * Attempts to write beyond the end of the block will fail silently
+ */
+void hal_write_flash(u32 offset,const u8 *data, u32 length);
+
 // ____________________________________________________________________________
 //
 // Callbacks from the hardware (implemented in your app.c)
diff --git a/include/app_defs.h b/include/app_defs.h
index 829f8a6..7a3efa1 100644
--- a/include/app_defs.h
+++ b/include/app_defs.h
@@ -100,5 +100,12 @@ typedef unsigned char  u8;
 #define MIDI_OUT_CABLE          1
 
 // ____________________________________________________________________________
+//
+// Flash storage
+// ____________________________________________________________________________
+
+#define USER_AREA_SIZE 1024
+
+// ____________________________________________________________________________
 
 #endif
diff --git a/lib/launchpad_pro.a b/lib/launchpad_pro.a
index 347b65e..907c72a 100644
--- a/lib/launchpad_pro.a
+++ b/lib/launchpad_pro.a
diff --git a/src/app.c b/src/app.c
index f0edec8..e250cd3 100644
--- a/src/app.c
+++ b/src/app.c
@@ -41,6 +41,15 @@
 //
 // This is where the fun is!  Add your code to the callbacks below to define how
 // your app behaves.
+//
+// In this example, we store all button states in an array, which we sometimes
+// save to flash.
+//______________________________________________________________________________
+
+#define BUTTON_COUNT 100
+
+u8 g_Buttons[BUTTON_COUNT] = {0};
+
 //______________________________________________________________________________
 
 void app_surface_event(u8 type, u8 index, u8 value)
@@ -49,16 +58,28 @@ void app_surface_event(u8 type, u8 index, u8 value)
         {
                 case  TYPEPAD:
                 {
-                        // example - light / extinguish pad LEDs, send MIDI
-                        hal_plot_led(TYPEPAD, index, value, value, value);
+                        // toggle it and store it off, so we can save to flash if we want to
+                        if (value)
+                        {
+                                g_Buttons[index] = MAXLED * !g_Buttons[index];
+                        }
+                        
+                        // example - light / extinguish pad LEDs
+                        hal_plot_led(TYPEPAD, index, 0, 0, g_Buttons[index]);
+                        
+                        // example - send MIDI
                         hal_send_midi(DINMIDI, NOTEON | 0, index, value);
+                        
                 }
                 break;
 
                 case TYPESETUP:
                 {
-                        // example - light the setup LED
-                        hal_plot_led(TYPESETUP, 0, value, value, value);
+                        if (value)
+                        {
+                                // save button states to flash (reload them by power cycling the hardware!)
+                                hal_write_flash(0, g_Buttons, BUTTON_COUNT);
+                        }
                 }
                 break;
         }
@@ -137,16 +158,17 @@ void app_timer_event()
 
 void app_init()
 {
+        // example - load button states from flash
+        hal_read_flash(0, g_Buttons, BUTTON_COUNT);
+        
     // example - light the LEDs to say hello!
         for (int i=0; i < 10; ++i)
         {
                 for (int j=0; j < 10; ++j)
                 {
-                        u8 r = i < 5 ? (MAXLED * (5-i))/5 : 0;
-                        u8 g = i < 5 ? (MAXLED * i)/5 : (MAXLED * (10-i))/5;
-                        u8 b = i < 5 ? 0 : (MAXLED * (i-5))/5;
+                        u8 b = g_Buttons[j*10 + i];
 
-                        hal_plot_led(TYPEPAD, j*10 + i, r, b, g);
+                        hal_plot_led(TYPEPAD, j*10 + i, 0, 0, b);
                 }
         }
 }
diff --git a/tools/simulator.c b/tools/simulator.c
index 56298d7..0df95ab 100644
--- a/tools/simulator.c
+++ b/tools/simulator.c
@@ -57,6 +57,16 @@ void hal_send_sysex(u8 port, const u8* data, u16 length)
         printf("...hal_send_midi(%d, (data), %d);\n", port, length);
 }
 
+void hal_read_flash(u32 offset, u8 *data, u32 length)
+{
+        printf("...hal_read_flash(%d, (data), %d);\n", offset, length);
+}
+
+void hal_write_flash(u32 offset,const u8 *data, u32 length)
+{
+        printf("...hal_write_flash(%d, (data), %d);\n", offset, length);
+}
+
 // ____________________________________________________________________________
 //
 // App event wrappers - these just log to the console.  Would be nice to wire