Revision 0:ce7a8546502b, committed 2010-01-16
- Comitter:
- okano
- Date:
- Sat Jan 16 02:41:51 2010 +0000
- Commit message:
Changed in this revision
diff -r 000000000000 -r ce7a8546502b main.cpp
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sat Jan 16 02:41:51 2010 +0000
@@ -0,0 +1,140 @@
+/*
+ * NXP LM75B temperature sensor test
+ * www.nxp.com/pip/LM75B_2.html
+ *
+ * Expecting to use the pins 9 and 10 for I2C bus
+ * these pins should be pulled-up properly.
+ *
+ * The temperature read out will be shown on terminal on the PC screen.
+ *
+ * In this demo code, two LM75B devices can be driven.
+ * These two devices should have different I2C address setting
+ * using its address pins (LM75B's A0 to A2 (pins 5 to 7)).
+ * One LM75B should have all those pins tied to GND.
+ * And another should have the pin A0(pin7) pulled-up.
+ *
+ * From the software, those devices can be accessed by I2C addresses
+ * "0x90" and "0x92".
+ * It will not be as "0x90" and "0x91" because the address has
+ * 7 bit only and stuffed to left. So the "A0" setting become 0xX2.
+ * The LSB does not care because it will be set by I2C libraly when
+ * it transfer the data for read and write.
+ */
+
+#include "mbed.h"
+//#include "SDFileSystem.h"
+
+// LM75B IIC address
+#define LM75B_ADDR 0x90
+
+// LM75B registers
+#define Conf 0x01
+#define Temp 0x00
+#define Tos 0x03
+#define Thyst 0x02
+
+
+DigitalOut led[] = { LED4, LED3, LED2, LED1 };
+Serial pc(USBTX, USBRX); // tx, rx
+
+I2C i2c( p9, p10 ); // sda, scl
+
+
+void iic_write( char addr, char reg, char data );
+char iic_read( char addr, char reg );
+short iic_read_short( char addr, char reg );
+void iic_error( void );
+
+void init_temp_sensor( char dev_num );
+float get_temp( char dev_num );
+
+int main() {
+ int i;
+
+ init_temp_sensor( 0 );
+ init_temp_sensor( 1 );
+
+ while(1) {
+ pc.printf( " (%d) temp[0]=%6.3f, temp[1]=%6.3f(degree-C)\n", i++, get_temp( 0 ), get_temp( 1 ) );
+ wait( 1 );
+ }
+}
+
+void init_temp_sensor( char dev_num )
+{
+ dev_num <<= 1;
+
+ iic_write( LM75B_ADDR | dev_num, Conf, 0x00 ); // configuration
+ pc.printf( "sensor[%d] : Conf register read out = 0x%02X\n", dev_num, iic_read( LM75B_ADDR | dev_num, Conf ) );
+ pc.printf( "sensor[%d] : Tos register read out = 0x%04X\n", dev_num, iic_read_short( LM75B_ADDR | dev_num, Tos ) );
+ pc.printf( "sensor[%d] : Thyst register read out = 0x%04X\n", dev_num, iic_read_short( LM75B_ADDR | dev_num, Thyst ) );
+}
+
+
+float get_temp( char dev_num )
+{
+ dev_num <<= 1;
+
+ return ( (float)(iic_read_short( LM75B_ADDR | dev_num, Temp )) / 256.0 );
+}
+
+void iic_write( char addr, char reg, char data )
+{
+ char cmd[2];
+
+ cmd[ 0 ] = reg;
+ cmd[ 1 ] = data;
+
+ if ( i2c.write( addr, cmd, 2) )
+ iic_error();
+}
+
+char iic_read( char addr, char reg )
+{
+ char cmd;
+ int nack;
+
+ cmd = reg;
+
+ nack = i2c.write( addr, &cmd, 1); // Send command string
+ nack |= i2c.read( addr, &cmd, 1); // Send command string
+
+ if ( nack )
+ iic_error();
+
+ return ( cmd );
+}
+
+
+short iic_read_short( char addr, char reg )
+{
+ char cmd[ 2 ];
+ int nack;
+
+ cmd[ 0 ] = reg;
+
+ nack = i2c.write( addr, cmd, 1); // Send command string
+ nack |= i2c.read( addr, cmd, 2); // Send command string
+
+ if ( nack )
+ iic_error();
+
+ return ( ((short)cmd[ 0 ]) << 8 | cmd[ 1 ] );
+}
+
+
+void iic_error( void )
+{
+ pc.printf( "I2C error\n" );
+
+ for ( int i = 0; i < 4; i++ )
+ led[ i ] = i & 0x01;
+
+ wait ( 0.2 );
+
+ for ( int i = 0; i < 4; i++ )
+ led[ i ] = !(i & 0x01);
+
+ wait ( 0.2 );
+}
+
diff -r 000000000000 -r ce7a8546502b mbed.bld
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed.bld Sat Jan 16 02:41:51 2010 +0000
@@ -0,0 +1,1 @@
+http://mbed.org/users/mbed_official/code/mbed/builds/49a220cc26e0
Tedd OKANO