app-board-LM75 - BULME

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Franz Wolf / Mbed 2 deprecated app-board-LM75

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main.cpp@0:ce7a8546502b, 2010-01-16 (annotated)

Committer:: okano
Date:: Sat Jan 16 02:41:51 2010 +0000
Revision:: 0:ce7a8546502b
Child:: 1:6484448034e3

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User	Revision	Line number	New contents of line
okano	0:ce7a8546502b	1	/*
okano	0:ce7a8546502b	2	* NXP LM75B temperature sensor test
okano	0:ce7a8546502b	3	* www.nxp.com/pip/LM75B_2.html
okano	0:ce7a8546502b	4	*
okano	0:ce7a8546502b	5	* Expecting to use the pins 9 and 10 for I2C bus
okano	0:ce7a8546502b	6	* these pins should be pulled-up properly.
okano	0:ce7a8546502b	7	*
okano	0:ce7a8546502b	8	* The temperature read out will be shown on terminal on the PC screen.
okano	0:ce7a8546502b	9	*
okano	0:ce7a8546502b	10	* In this demo code, two LM75B devices can be driven.
okano	0:ce7a8546502b	11	* These two devices should have different I2C address setting
okano	0:ce7a8546502b	12	* using its address pins (LM75B's A0 to A2 (pins 5 to 7)).
okano	0:ce7a8546502b	13	* One LM75B should have all those pins tied to GND.
okano	0:ce7a8546502b	14	* And another should have the pin A0(pin7) pulled-up.
okano	0:ce7a8546502b	15	*
okano	0:ce7a8546502b	16	* From the software, those devices can be accessed by I2C addresses
okano	0:ce7a8546502b	17	* "0x90" and "0x92".
okano	0:ce7a8546502b	18	* It will not be as "0x90" and "0x91" because the address has
okano	0:ce7a8546502b	19	* 7 bit only and stuffed to left. So the "A0" setting become 0xX2.
okano	0:ce7a8546502b	20	* The LSB does not care because it will be set by I2C libraly when
okano	0:ce7a8546502b	21	* it transfer the data for read and write.
okano	0:ce7a8546502b	22	*/
okano	0:ce7a8546502b	23
okano	0:ce7a8546502b	24	#include "mbed.h"
okano	0:ce7a8546502b	25	//#include "SDFileSystem.h"
okano	0:ce7a8546502b	26
okano	0:ce7a8546502b	27	// LM75B IIC address
okano	0:ce7a8546502b	28	#define LM75B_ADDR 0x90
okano	0:ce7a8546502b	29
okano	0:ce7a8546502b	30	// LM75B registers
okano	0:ce7a8546502b	31	#define Conf 0x01
okano	0:ce7a8546502b	32	#define Temp 0x00
okano	0:ce7a8546502b	33	#define Tos 0x03
okano	0:ce7a8546502b	34	#define Thyst 0x02
okano	0:ce7a8546502b	35
okano	0:ce7a8546502b	36
okano	0:ce7a8546502b	37	DigitalOut led[] = { LED4, LED3, LED2, LED1 };
okano	0:ce7a8546502b	38	Serial pc(USBTX, USBRX); // tx, rx
okano	0:ce7a8546502b	39
okano	0:ce7a8546502b	40	I2C i2c( p9, p10 ); // sda, scl
okano	0:ce7a8546502b	41
okano	0:ce7a8546502b	42
okano	0:ce7a8546502b	43	void iic_write( char addr, char reg, char data );
okano	0:ce7a8546502b	44	char iic_read( char addr, char reg );
okano	0:ce7a8546502b	45	short iic_read_short( char addr, char reg );
okano	0:ce7a8546502b	46	void iic_error( void );
okano	0:ce7a8546502b	47
okano	0:ce7a8546502b	48	void init_temp_sensor( char dev_num );
okano	0:ce7a8546502b	49	float get_temp( char dev_num );
okano	0:ce7a8546502b	50
okano	0:ce7a8546502b	51	int main() {
okano	0:ce7a8546502b	52	int i;
okano	0:ce7a8546502b	53
okano	0:ce7a8546502b	54	init_temp_sensor( 0 );
okano	0:ce7a8546502b	55	init_temp_sensor( 1 );
okano	0:ce7a8546502b	56
okano	0:ce7a8546502b	57	while(1) {
okano	0:ce7a8546502b	58	pc.printf( " (%d) temp[0]=%6.3f, temp[1]=%6.3f(degree-C)\n", i++, get_temp( 0 ), get_temp( 1 ) );
okano	0:ce7a8546502b	59	wait( 1 );
okano	0:ce7a8546502b	60	}
okano	0:ce7a8546502b	61	}
okano	0:ce7a8546502b	62
okano	0:ce7a8546502b	63	void init_temp_sensor( char dev_num )
okano	0:ce7a8546502b	64	{
okano	0:ce7a8546502b	65	dev_num <<= 1;
okano	0:ce7a8546502b	66
okano	0:ce7a8546502b	67	iic_write( LM75B_ADDR \| dev_num, Conf, 0x00 ); // configuration
okano	0:ce7a8546502b	68	pc.printf( "sensor[%d] : Conf register read out = 0x%02X\n", dev_num, iic_read( LM75B_ADDR \| dev_num, Conf ) );
okano	0:ce7a8546502b	69	pc.printf( "sensor[%d] : Tos register read out = 0x%04X\n", dev_num, iic_read_short( LM75B_ADDR \| dev_num, Tos ) );
okano	0:ce7a8546502b	70	pc.printf( "sensor[%d] : Thyst register read out = 0x%04X\n", dev_num, iic_read_short( LM75B_ADDR \| dev_num, Thyst ) );
okano	0:ce7a8546502b	71	}
okano	0:ce7a8546502b	72
okano	0:ce7a8546502b	73
okano	0:ce7a8546502b	74	float get_temp( char dev_num )
okano	0:ce7a8546502b	75	{
okano	0:ce7a8546502b	76	dev_num <<= 1;
okano	0:ce7a8546502b	77
okano	0:ce7a8546502b	78	return ( (float)(iic_read_short( LM75B_ADDR \| dev_num, Temp )) / 256.0 );
okano	0:ce7a8546502b	79	}
okano	0:ce7a8546502b	80
okano	0:ce7a8546502b	81	void iic_write( char addr, char reg, char data )
okano	0:ce7a8546502b	82	{
okano	0:ce7a8546502b	83	char cmd[2];
okano	0:ce7a8546502b	84
okano	0:ce7a8546502b	85	cmd[ 0 ] = reg;
okano	0:ce7a8546502b	86	cmd[ 1 ] = data;
okano	0:ce7a8546502b	87
okano	0:ce7a8546502b	88	if ( i2c.write( addr, cmd, 2) )
okano	0:ce7a8546502b	89	iic_error();
okano	0:ce7a8546502b	90	}
okano	0:ce7a8546502b	91
okano	0:ce7a8546502b	92	char iic_read( char addr, char reg )
okano	0:ce7a8546502b	93	{
okano	0:ce7a8546502b	94	char cmd;
okano	0:ce7a8546502b	95	int nack;
okano	0:ce7a8546502b	96
okano	0:ce7a8546502b	97	cmd = reg;
okano	0:ce7a8546502b	98
okano	0:ce7a8546502b	99	nack = i2c.write( addr, &cmd, 1); // Send command string
okano	0:ce7a8546502b	100	nack \|= i2c.read( addr, &cmd, 1); // Send command string
okano	0:ce7a8546502b	101
okano	0:ce7a8546502b	102	if ( nack )
okano	0:ce7a8546502b	103	iic_error();
okano	0:ce7a8546502b	104
okano	0:ce7a8546502b	105	return ( cmd );
okano	0:ce7a8546502b	106	}
okano	0:ce7a8546502b	107
okano	0:ce7a8546502b	108
okano	0:ce7a8546502b	109	short iic_read_short( char addr, char reg )
okano	0:ce7a8546502b	110	{
okano	0:ce7a8546502b	111	char cmd[ 2 ];
okano	0:ce7a8546502b	112	int nack;
okano	0:ce7a8546502b	113
okano	0:ce7a8546502b	114	cmd[ 0 ] = reg;
okano	0:ce7a8546502b	115
okano	0:ce7a8546502b	116	nack = i2c.write( addr, cmd, 1); // Send command string
okano	0:ce7a8546502b	117	nack \|= i2c.read( addr, cmd, 2); // Send command string
okano	0:ce7a8546502b	118
okano	0:ce7a8546502b	119	if ( nack )
okano	0:ce7a8546502b	120	iic_error();
okano	0:ce7a8546502b	121
okano	0:ce7a8546502b	122	return ( ((short)cmd[ 0 ]) << 8 \| cmd[ 1 ] );
okano	0:ce7a8546502b	123	}
okano	0:ce7a8546502b	124
okano	0:ce7a8546502b	125
okano	0:ce7a8546502b	126	void iic_error( void )
okano	0:ce7a8546502b	127	{
okano	0:ce7a8546502b	128	pc.printf( "I2C error\n" );
okano	0:ce7a8546502b	129
okano	0:ce7a8546502b	130	for ( int i = 0; i < 4; i++ )
okano	0:ce7a8546502b	131	led[ i ] = i & 0x01;
okano	0:ce7a8546502b	132
okano	0:ce7a8546502b	133	wait ( 0.2 );
okano	0:ce7a8546502b	134
okano	0:ce7a8546502b	135	for ( int i = 0; i < 4; i++ )
okano	0:ce7a8546502b	136	led[ i ] = !(i & 0x01);
okano	0:ce7a8546502b	137
okano	0:ce7a8546502b	138	wait ( 0.2 );
okano	0:ce7a8546502b	139	}
okano	0:ce7a8546502b	140

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	17 Sep 2019
Imports:	28
Forks:	0
Commits:	7
Dependents:	0
Dependencies:	2
Followers:	2

main.cpp@0:ce7a8546502b, 2010-01-16 (annotated)

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