Revision 3:d3be72ac889e, committed 2018-06-19

Comitter:

martinsimpson

Date:

Tue Jun 19 11:19:34 2018 +0000

Parent:

2:70039cc8ba02

Commit message:

V3 changed Data output routine and sorted sclk for phase selection

Changed in this revision

--- a/SWSPI_HD.cpp	Tue Jun 19 10:49:39 2018 +0000
+++ b/SWSPI_HD.cpp	Tue Jun 19 11:19:34 2018 +0000
@@ -23,10 +23,11 @@
 #include <mbed.h>
 #include "SWSPI_HD.h"
 
-SWSPI_HD::SWSPI_HD(PinName dio_pin, PinName sclk_pin)
+SWSPI_HD::SWSPI_HD(PinName dio_pin, PinName sclk_pin, PinName cs_pin)
 {
     dio = new DigitalInOut(dio_pin);
     sclk = new DigitalOut(sclk_pin);
+    cs = new DigitalOut(cs_pin,true);
     format(8);
     frequency();
 }
@@ -35,6 +36,7 @@
 {
     delete dio;
     delete sclk;
+    delete cs;
 }
 
 void SWSPI_HD::format(int bits, int mode)
@@ -54,19 +56,20 @@
 int SWSPI_HD::write(int value)
 {
     int read = 0;
-
+    //ensure clock is in right phase to start and disable slave device
+    cs->write(true);
+    sclk->write(!polarity);
+    
     //Write Out
     dio->output();// set as an OUTPUT
-    
+    cs->write(false);//select slave device (active low)
     for (int bit = bits-1; bit >= 0; --bit)
     {
-        dio->output();// set as an OUTPUT
-        
         dio->write(((value >> bit) & 0x01) != 0);
-
+        wait(1.0/freq/2);
         sclk->write(!polarity);
-
         wait(1.0/freq/2);
+        sclk->write(polarity);
     }
     
     //Read In
@@ -79,6 +82,11 @@
             if (dio->read())   // was miso
                 read |= (1 << bit);
         }
+        
+        sclk->write(!polarity);
+
+        wait(1.0/freq/2);
+        
         if (phase == 1)
         {
             if (dio->read())   // was miso
@@ -89,6 +97,7 @@
 
         wait(1.0/freq/2);
     }
+    cs->write(true);
     return read;
 }
 

--- a/SWSPI_HD.h	Tue Jun 19 10:49:39 2018 +0000
+++ b/SWSPI_HD.h	Tue Jun 19 11:19:34 2018 +0000
@@ -37,11 +37,10 @@
  * #include "mbed.h"
  * #include "SWSPI_HD.h"
  * 
- * SWSPI_HD spi(D8, D7); // dio, sclk (Using Arduino form factor Board (NUCLEO-32F401RE)
+ * SWSPI_HD spi(D8, D7, D6); // dio, sclk (n)cs (Using Arduino form factor Board (NUCLEO-32F401RE)
  * 
  * int main() 
  * {
- *     DigitalOut cs(D6);
  *     spi.format(8, 0);
  *     spi.frequency(10000000);
  *     cs.write(0);
@@ -56,6 +55,7 @@
 private:
     DigitalInOut* dio;
     DigitalOut* sclk;
+    DigitalOut* cs;
     int port;
     int bits;
     int mode;
@@ -69,7 +69,7 @@
      *  @param dio
      *  @param sclk_pin
      */
-    SWSPI_HD(PinName dio_pin, PinName sclk_pin);
+    SWSPI_HD(PinName dio_pin, PinName sclk_pin, PinName cs_pin);
     
     /** Destructor */
     ~SWSPI_HD();