Revision 0:f9b5c272f6ed, committed 2016-05-06

Comitter:

skelter

Date:

Fri May 06 18:50:55 2016 +0000

Commit message:

commit start

Changed in this revision

diff -r 000000000000 -r f9b5c272f6ed main.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Fri May 06 18:50:55 2016 +0000
@@ -0,0 +1,27 @@
+/* 
+    Read analog channel from MCP3201 with SPI interface and send it to the serial interface.
+*/
+
+#include "mbed.h"
+#include "mcp3201.h"
+
+#define ADC_SCALE_VALUE 3.3/4096 
+
+Serial pc(USBTX, USBRX); // tx, rx
+ 
+int main() 
+{
+    pc.printf("Analog read test from MCP3201.\n");
+    
+    while(1) 
+    {    
+    float r=(float)ReadAnalogMCP3201() * ADC_SCALE_VALUE; // show value in volts.
+    pc.printf("AD channel value: %4.2f Volts.\r\n", r);
+    pc.printf(" Press any key to get new sample...\r\n\r\n");
+    char c = pc.getc();
+    }
+}
+
+
+    
+

diff -r 000000000000 -r f9b5c272f6ed mbed.bld
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld	Fri May 06 18:50:55 2016 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/99a22ba036c9
\ No newline at end of file

diff -r 000000000000 -r f9b5c272f6ed mcp3201.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mcp3201.h	Fri May 06 18:50:55 2016 +0000
@@ -0,0 +1,35 @@
+/*
+    Header for MCP3201 Analog SAR Converter with SPI interface 
+    Version: 1.0
+    Julio S.
+*/
+
+// SPI clock freq. in HZ
+// Limits from MCP3201 datasheet are:
+// 1500000Hz when vdd=5V
+// 800000Hz when vdd=2.7V
+// 1MHz should work and is the default value.
+#define MCP3201_CLK_FREQ    1000000
+
+// MCP3201 SPI channel pinout
+// p5 not wired, there are no commands to send for MCP3201 device
+SPI MCP3201(p5,p6,p7);
+// take control from CS pin to avoid transition changes between write commands
+DigitalOut cs(p8); 
+
+
+// Read the analog value from MCP3201.
+// return 12bit interger (0...4095)
+int ReadAnalogMCP3201(void)
+{
+ //uncommente below line only if the MCP3201_CLK_FREQ is diferrent of 1MHz
+ //MCP3201.frequency(MCP3201_CLK_FREQ);
+ 
+ cs=0;
+ int high_byte = MCP3201.write(0x00);
+ int low_byte = MCP3201.write(0x00);
+ cs=1;
+ int conv_result = ((high_byte & 0x1f) << 7) | ((low_byte >> 1) & 0x7f);  
+
+ return conv_result;
+}
\ No newline at end of file