Increase message size. Add gdb script.

.gdbinit

@@ -0,0 +1,14 @@
+  define btload
+    file build/bbc-microbit-classic-gcc-nosd/source/pyb-radio-module
+    target extended-remote /dev/ttyACM0
+    monitor swdp_scan
+    attach 1
+    set mem inaccessible-by-default off
+    mon erase_mass
+    load
+  end
+
+  define btreset
+    set mem inaccessible-by-default off
+    set *0xe000ed0c = 0x05fa << 16 | (1 << 2)
+  end

inc/SPISlaveExt.h

@@ -27,7 +27,7 @@ DEALINGS IN THE SOFTWARE.
 
 #include "mbed.h"
 
-const uint8_t SPI_IOBUF_SIZE = 64;
+const uint16_t SPI_IOBUF_SIZE = 255;
 
 typedef enum {
     SPI_OP_SUCCESS,
@@ -68,7 +68,7 @@ class SPISlaveExt : public SPISlave {
          * buffer is where we should place bytes
          * maxLen is the size of the buffer
          * release tells us whether to release the CPU semaphore after operating.
-         *   If we want to respond we should keep hold of the semaphore, however 
+         *   If we want to respond we should keep hold of the semaphore, however
          *   we MUST then call release before the device will send any messages.
          *
          */

source/SPIRadio.cpp

@@ -35,7 +35,7 @@ extern SPISlaveExt spi;
 
 // Radio messages buffer
 extern uint8_t radio_buffer_len;
-extern uint8_t radio_buffer[64];
+extern uint8_t radio_buffer[SPI_IOBUF_SIZE];
 // Version info prototype
 const char* version_info(void);
 
@@ -68,7 +68,7 @@ uint8_t validate_packet(const uint8_t *io_buffer, const uint32_t length) {
 spi_op_status_t craft_packet(uint8_t *io_buffer, spi_radio_responses_t resp,
         const uint8_t *msg, const uint32_t length) {
     // Check that our message isn't too long
-    if (length > 61)
+    if (length > SPI_IOBUF_SIZE - 4)
         return SPI_OP_INSUFFICIENT_BUFFER;
 
     // Calculate our checksum
@@ -178,7 +178,7 @@ void spi_cmd_switch(spi_radio_cmds_t cmd, uint8_t *io_buffer, const uint32_t len
                 spi.reply(SPI_INVALID_LENGTH);
                 break;
             }
-            if (check > 61) {
+            if (check > SPI_IOBUF_SIZE - 4) {
                 spi.reply(SPI_REPLY_OVERFLOW);
                 break;
             }

source/main.cpp

@@ -47,8 +47,8 @@ SPISlaveExt spi(P0_22, P0_23, P0_21, P0_24); // MOSI, MISO, SCLK, CS
 
 // Allocate space for a message buffer
 uint8_t radio_buffer_len;
-uint8_t radio_buffer[64];
-uint8_t io_buffer[64];
+uint8_t radio_buffer[SPI_IOBUF_SIZE];
+uint8_t io_buffer[SPI_IOBUF_SIZE];
 
 void onRadioMsg(MicroBitEvent e) {
     ManagedString s = module.radio.datagram.recv();
@@ -90,7 +90,7 @@ int main()
           spi.release();
         // If we have, handle it
         if (r) {
-            spi_op_status_t success = spi.read_buffer(io_buffer, 64, 0);
+          spi_op_status_t success = spi.read_buffer(io_buffer, sizeof(io_buffer), 0);
             if (success != SPI_OP_SUCCESS)
                 continue;
             spi_radio_cmds_t cmd = (spi_radio_cmds_t) io_buffer[0];