make SPI work by understanding how it actually works

git-svn-id: https://svn.spreadspace.org/mur.sat@419 7de4ea59-55d0-425e-a1af-a3118ea81d4c

1 files changed, 40 insertions, 20 deletions

diff --git a/software/hhd70dongle/c1101lib.c b/software/hhd70dongle/c1101lib.c
index 8f9f5a7..cda199b 100644
--- a/software/hhd70dongle/c1101lib.c
+++ b/software/hhd70dongle/c1101lib.c
@@ -40,6 +40,8 @@
 /**** Helper Functions ****/
 
 #define SPIC1101_MAX_WAIT 1024
+#define SPIC1101_SEND_MOSTLY_HARMLESS 0
+
 unsigned int attempts = 0;
 char spi_c1101_exchange(char *data, int len)
 {
@@ -51,20 +53,23 @@ char spi_c1101_exchange(char *data, int len)
     while (len-- > 0)
     {
         //~ while ( ! (SPIC1101_SB_CHIPRDY(spi_read_byte())));
-        spi_write_byte(*(data++));
+        sb = spi_exchange_byte(*data);
         usb_rawhid_send((uint8_t*)"spi byte written",255);        
-        do
+        debug_sprint_int16hex(debug_sb, sb);
+        usb_rawhid_send(debug_sb,255);        
+        while ( ! (SPIC1101_SB_CHIPRDY(sb)));
         {
-            usb_rawhid_send((uint8_t*)"wait chipready",255);
-            sb = spi_read_byte();
+            usb_rawhid_send((uint8_t*)"not yet chipready",255);
+            sb = spi_exchange_byte(*data);
             debug_sprint_int16hex(debug_sb, sb);
             usb_rawhid_send(debug_sb,255);
             if (attempts++ > SPIC1101_MAX_WAIT)
                 return -1;
-        } while ( ! (SPIC1101_SB_CHIPRDY(sb)));
+        }
         usb_rawhid_send((uint8_t*)"spi chipready",255);
+        data++;
     }
-    rbyte = spi_read_byte();
+    rbyte = spi_exchange_byte(SPIC1101_SEND_MOSTLY_HARMLESS);
     usb_rawhid_send((uint8_t*)"spi byte read",255);
     spi_cs_disable();
     return rbyte;
@@ -98,21 +103,29 @@ char spi_c1101_strobe_command(char address)
 int spi_c1101_read_rxfifo(int leave_num_bytes, char *buffer, int maxlen)
 {
     char sb;
+    uint8_t debug_sb[6];
+    attempts = 0;
     int num_read = 0;
     int num_fifo_available = 0;
     spi_cs_enable();
-    while ( ! (SPIC1101_SB_CHIPRDY(spi_read_byte())));
-    spi_write_byte(SPIC1101_ADDR_FIFO_READ_BURST);
-    do
+    sb = spi_exchange_byte(SPIC1101_ADDR_FIFO_READ_BURST);
+    while ( ! (SPIC1101_SB_CHIPRDY(sb)));
     {
-        sb = spi_read_byte();
-    } while ( ! (SPIC1101_SB_CHIPRDY(sb)));
+        usb_rawhid_send((uint8_t*)"not yet chipready",255);
+        sb = spi_exchange_byte(SPIC1101_ADDR_FIFO_READ_BURST);
+        debug_sprint_int16hex(debug_sb, sb);
+        usb_rawhid_send(debug_sb,255);
+        if (attempts++ > SPIC1101_MAX_WAIT)
+            return -1;
+    }
+    usb_rawhid_send((uint8_t*)"spi chipready",255);
     num_fifo_available = SPIC1101_SB_FIFO_BYTES_AVAILABLE(sb);
-    
+    //note if num_fifo_available  == 15 then 15 or more bytes are available
+    //FIXTHIS
     while (maxlen-- && num_fifo_available - num_read <= leave_num_bytes)
     {
         //hope this works !!
-        buffer[num_read++] = spi_read_byte();
+        buffer[num_read++] = spi_exchange_byte(SPIC1101_SEND_MOSTLY_HARMLESS);
     }
     spi_cs_disable();
     return num_read;
@@ -122,18 +135,25 @@ int spi_c1101_read_rxfifo(int leave_num_bytes, char *buffer, int maxlen)
 int spi_c1101_write_txfifo(char *buffer, int len)
 {
     char sb;
+    uint8_t debug_sb[6];
+    attempts = 0;
     int num_written = 0;
     int num_fifo_available = 0;
     spi_cs_enable();
-    while ( ! (SPIC1101_SB_CHIPRDY(spi_read_byte())));
-    spi_write_byte(SPIC1101_ADDR_FIFO_WRITE_BURST);
-    do
+    sb = spi_exchange_byte(SPIC1101_ADDR_FIFO_WRITE_BURST);
+    while ( ! (SPIC1101_SB_CHIPRDY(sb)));
     {
-        sb = spi_read_byte();
-    } while ( ! (SPIC1101_SB_CHIPRDY(sb)));
+        usb_rawhid_send((uint8_t*)"not yet chipready",255);
+        sb = spi_exchange_byte(SPIC1101_ADDR_FIFO_WRITE_BURST);
+        debug_sprint_int16hex(debug_sb, sb);
+        usb_rawhid_send(debug_sb,255);
+        if (attempts++ > SPIC1101_MAX_WAIT)
+            return -1;
+    }
+    usb_rawhid_send((uint8_t*)"spi chipready",255);
     num_fifo_available = SPIC1101_SB_FIFO_BYTES_AVAILABLE(sb);
-    
-    //if there is less space in tx-fifo than num-byte we want to send, only fill fifo until full and leave rest of buffer unsent (for now)
+    //note if num_fifo_available  == 15 then 15 or more bytes are available
+    //FIXTHIS
     if (num_fifo_available < len)
         len = num_fifo_available;