Timo Karppinen / Mbed OS McLab08_SPI_Pmod_ALS1_OS6

The code is developed for the hardware NUCLEO-L432KC or any other board with SPI communication and the Digilent Pmod ALS1 ambient light sensor module. The purpose is to make students to understand the development process. They need to study the original analog to digital converter documentation to understand how the converter 16 bit output is converted to an illuminance value.

Diff: main.cpp

Revision:
1:444f907aa5eb
Parent:
0:fb0f74ee7b70
--- a/main.cpp	Tue Nov 17 16:01:26 2020 +0000
+++ b/main.cpp	Sun Jan 09 19:07:52 2022 +0000
@@ -32,6 +32,7 @@
 * 
 * Timo Karppinen 17.11.2020
 **************************************************************/
+#include "ThisThread.h"
 #include "mbed.h"
 
 DigitalOut LED(D1);  // LD1 to LD4 pin names are linked to D13 in L432KC.
@@ -48,11 +49,12 @@
 {   
 // SPI for the ALS        
         // Setup the spi for 8 bit data, high steady state clock,
-        // second edge capture, with a 12MHz clock rate
+        // second edge capture, with a 2MHz clock rate
         spi.format(8,0);           
-        spi.frequency(12000000);
+        spi.frequency(2000000);
         // ready to wait the conversion start
         alsCS.write(1);
+        ThisThread::sleep_for(1ms);
 
     while (true) {
      
@@ -85,10 +87,12 @@
     // Begin the conversion process and serial data output
     alsCS.write(0); 
     // Reading two 8bit bytes by writing two dymmy 8bit bytes
+    ThisThread::sleep_for(1ms);
     alsByte0 = spi.write(0x00);
     alsByte1 = spi.write(0x00);
     // End of serial data output and back to tracking mode
     alsCS.write(1);
+    ThisThread::sleep_for(1ms);
     // Check the http://www.ti.com/lit/ds/symlink/adc081s021.pdf
     // shifting bits to get the number out
     alsByteSh0 = alsByte0 << 4;