One last BMP085 Project...

[gwdeveloper 275]

The G2211 has neither.

 

You can see how the same code and BMP085 sensor was implemented on a F5529 at http://www.43oh.com/forum/viewtopic.php?f=8&t=1058&hilit=weather+station

[pfactorial 7]

oh. So only a G2553 would work...okaythen.

[displacedtexan 1]

Hmm... I just downloaded it and imported it into CCS v5.1 and get the following errors when I try to compile:

 

 

Description Resource Path Location Type

errors encountered during linking; "bmp085_2553.out" not built bmp085_2553 C/C++ Problem

unresolved symbol uart_TX_isr, first referenced in C:\Users\Jason\workspace_v5_1\bmp085_2553\src\csl/csl.lib bmp085_2553 C/C++ Problem

unresolved symbol watchdog_isr, first referenced in C:\Users\Jason\workspace_v5_1\bmp085_2553\src\csl/csl.lib bmp085_2553 C/C++ Problem

unresolved symbols remain bmp085_2553 C/C++ Problem

 

I went back and selected the "Enable Watchdog Timer Interrupt" in WDT+ under Grace. Same for the uart_TX_isr interrupt under USCI_A for the Transmit Interrupt.

 

Any ideas on how to resolve?

 

Thanks!

[gwdeveloper 275]

Not sure what's going on. I created that project in v4 a while back. It's already imported and working in v5.1 for me but it was imported quite a while ago. Not sure if I changed anything to get it going. Give me a bit and I'll check on it. If needed, I'll re-upload the project files.

 

EDIT: Ok, the files are cleaned and uploaded. I found where the issue was. Initially, when building the program, I had used the WDT and TX isr. Those were removed as the WDT wasn't needed and the UART tx was moved to a function instead of isr. In v4.2 it was ok to leave a function name in the box and just uncheck the use isr box. In v5.1, that's not the case -they need to be empty slots.

 

Please check the first post to download the updated project files.

[displacedtexan 1]

gwdeveloper, that's it!

 

I don't suppose you have played with one of those DHT22 humidity sensors? They are pretty cheap, but seem to use a non standard 1 wire interface. Probably a bit too complicated for me to get working...

 

Thanks!

[gwdeveloper 275]

Sorry, I haven't tested the DHT22 yet. I used the SHT21 for a while but the software for the i2c interface was bulky. Made the transition to only using Honeywell HIH-5031 analog humidity sensors and haven't looked back.

[gcgasson 0]

Hi. Just a question. I am using a MSP430f247 and I am using Grace to setup the hardware. You show UCB0I2CIE |= UCB0RXIE when init_rx. Is this correct? On the MSP430f247 there is no such field in the UCB0I2CIE. Am I making a mistake?

[pfactorial 7]

Ok, so the MSP-EXP430F5529 dev board may not provide me with optimal hardware I/O for my greenhouse controller. Basically, I'd want the power/speed of the F5529 without the accelerometer. If I were rebuilding this board, I'd move the LCD SPI over to UCA1 and free up UCB1 for an I2C channel. UCB0 is being used for the RF2500t interface. So...

 

My solution (for now) is to use a standalone G2553 as an I2C to UART translator. It actually works out well but not my optimal hardware configuration. This project may not be useful for many but some might find bits of the code helpful. The kicker, though, is I configured all of the hardware using Grace. :crazy:

 

If you have a BMP085, you can open a terminal on your launchpad port and receive temperature and barometric pressure.

 

/****************************************************************/
/* Greg Whitmore												*/
/* greg@gwdeveloper.net											*/
/* www.gwdeveloper.net									*/
/****************************************************************/
/* released under the "Use at your own risk" license			*/
/* use it how you want, where you want and have fun				*/
/* debugging the code.											*/
/* MSP-EXP430G2553												*/
/****************************************************************/

/* includes */
#include 
#include 
#include 

#include "itoa.h"

/* bmp085 defines */
#define BMP085_ADDR		0x77
#define BMP085_CTRL_REG 0xF4
#define BMP085_TEMP_REG 0x2E
#define BMP085_PRESSURE_REG 0x34		// oss =0
//#define BMP085_PRESSURE_REG_OSS1 0x74	// oss =1, longer delays needed 7.5ms
//#define BMP085_PRESSURE_REG_OSS2 0xB4 	// oss =2, 13.5ms
//#define BMP085_PRESSURE_REG_OSS3 0xF4 	// oss =3, 25.5ms
#define BMP085_MSB_REG	0xF6
#define BMP085_LSB_REG	0xF7
#define BMP085_CONV_REG_XLSB 0xF8

/* prototypes */
// bmp085
void bmp085_cal(void);
unsigned int bmp085_ut(void);
unsigned long bmp085_up(void);
void get_bmp085(void);

// iic
void iic_init(void);
void iic_tx_init(void);
void iic_rx_init(void);
void start_TX(void);
void start_RX(void);
int sendByte_getBytes(unsigned char reg_2_read, int bytes_to_rx);

//uart
void TXString( char* string, int length );

/* variables */
// bmp085
// cal data
int ac1;
int ac2;
int ac3;
unsigned int ac4;
unsigned int ac5;
unsigned int ac6;
int b1;
int b2;
int mb;
int mc;
int md;
// true temp
long ut;
long x1;
long x2;
long b5;
int bmp_temp = 0;
//true pressure
long up;
long x3;
long b3;
unsigned long b4;
long b6;
unsigned long b7;
long p;
long bmp_pres = 0;
// adjusters
long b6Temp;
long x1Temp;

//unsigned int i;

unsigned char temp_buffer[8];
unsigned char pres_buffer[8];

// tx constants
const unsigned char utTxData[] = { BMP085_CTRL_REG, BMP085_TEMP_REG };    // uncomp temp reg
const unsigned char upTxData[] = { BMP085_CTRL_REG, BMP085_PRESSURE_REG }; // oss =0 see bmp085.h
const unsigned char msbData[] = { BMP085_MSB_REG };

// iic
unsigned char *PTxData;                     	// Pointer to TX data
unsigned char TXByteCtr;

unsigned char *PRxData;                     	// Pointer to RX data
unsigned char RXByteCtr;
volatile unsigned char RxBuffer[3];       		// Allocate 3 byte of RAM

void main(void)
{
   CSL_init();                     // Activate Grace-generated configuration
   __enable_interrupt();           // Set global interrupt enable

   bmp085_cal(); 					// load calibration data

get_bmp085();					// loop to collect temp & pressure
								//  and TX via UART

}

// store PROM data into usable variables
void bmp085_cal(void)
{  
   ac1 = sendByte_getBytes(0xAA, 2);
   __delay_cycles(1000);
   ac2 = sendByte_getBytes(0xAC, 2);
   __delay_cycles(1000);
   ac3 = sendByte_getBytes(0xAE, 2);
   __delay_cycles(1000);    
   ac4 = sendByte_getBytes(0xB0, 2);
   __delay_cycles(1000);
   ac5 = sendByte_getBytes(0xB2, 2);
   __delay_cycles(1000);
   ac6 = sendByte_getBytes(0xB4, 2);
   __delay_cycles(1000);
   b1 =  sendByte_getBytes(0xB6, 2);
   __delay_cycles(1000);
   b2 =  sendByte_getBytes(0xB8, 2);
   __delay_cycles(1000);
   mb =  sendByte_getBytes(0xBA, 2);
   __delay_cycles(1000);
   mc =  sendByte_getBytes(0xBC, 2);
   __delay_cycles(1000);
   md =  sendByte_getBytes(0xBE, 2);
   __delay_cycles(1000);

}

// read uncompensated temperature and return msb & lsb
unsigned int bmp085_ut(void)
{
iic_tx_init();

__delay_cycles(1000);

PTxData = (unsigned char *)utTxData;		// send control reg and temp reg
TXByteCtr = 2;              				// Load TX byte counter

start_TX();

__delay_cycles(200000);   // long delay here or it hangs on the valueline mcus

return (sendByte_getBytes(BMP085_MSB_REG, 2));

}

// read uncompensated pressure and return msb, lsb & xlsb
unsigned long bmp085_up(void)
{
iic_tx_init();

__delay_cycles(1000);

PTxData = (unsigned char *)upTxData;		// send control reg and temp reg
TXByteCtr = 2;              				// Load TX byte counter

start_TX();

__delay_cycles(200000);			// long delay here or it hangs on the valueline mcus

   PTxData = (unsigned char *)msbData;		// send msb read register
TXByteCtr = 1;

start_TX();

iic_rx_init();						// set RX interrupt

   __delay_cycles(200000);			// long delay here or it hangs on the valueline mcus

   PRxData = (unsigned char *)RxBuffer;    // rx buffer
   RXByteCtr = 3;     			// number of bytes to receive

   start_RX();

   // returning longs instead of ints to allow 2^16 shifts
   // sendByte_getBytes not used here due to long shifts
   return ( (( (long)RxBuffer[0] << 16) | ( (long)RxBuffer[1] << 8) | (long)RxBuffer[2]) >> 8);

}

// collect uncompensated temp and pressure
// calculate compensated temp and pressure then transmit via UART
void get_bmp085()
{

while (1){

ut = bmp085_ut();
up = bmp085_up();

// calc true temp
x1 = ((long)ut - ac6) * ac5 >> 15;
   x2 = ((long)mc << 11) / (x1 + md);
   b5 = x1 + x2;
   bmp_temp = (b5 + 8) >> 4;

   // itoa function added
   itoa(bmp_temp, (char*)temp_buffer);			// move integer into char buffer

	// calc true pressure
   b6 = b5 - 4000;

//x1 = (b2 * (b6 * b6) >> 12) >> 11; // won't work this way on the value line LSR_23 error
b6Temp = b6 * b6;
x1Temp = b2 * b6Temp;
x1Temp = x1Temp >> 12;
x1 = x1Temp >> 11;

x2 = (ac2 * b6) >> 11;
x3 = x1 + x2;

b3 = ((long)ac1 * 4 + x3 + 2) >> 2;  // ????  so many 'corrections' on the web this one works though

x1 = ac3 * b6 >> 13;
x2 = (b1 * ((b6 * b6) >> 12)) >> 16;
x3 = ((x1 + x2) + 2) >> 2;
b4 = (ac4 * (unsigned long)(x3 + 32768)) >> 15;
b7 = ((unsigned long)up - b3) * 50000;

if (b7  < 0x80000000)
{ p = (b7 * 2) / b4;}
else {p = (b7 / b4) *2;}

x1 = (p >> 8) * (p >> 8);
x1 = (x1 * 3038) >> 16;
x2 = (-7357 * p) >> 16;
bmp_pres = p + ((x1 + x2 + 3791) >> 4);

   // ltoa part of stdlib.h
   ltoa(bmp_pres, (char*)pres_buffer);

   TXString((char*)temp_buffer, sizeof temp_buffer);
   TXString("\r\n", 2);
   TXString((char*)pres_buffer, sizeof pres_buffer);
   TXString("\r\n", 2);

  	__delay_cycles(500000);

}
}

void iic_tx_init()
{
UCB0I2CSA = BMP085_ADDR;
UCB0I2CIE |= UCB0TXIE;                       	// Enable TX interrupt
}
void iic_rx_init(void)
{
UCB0I2CIE |= UCB0RXIE;							// enable RX interrupt	
}

// send 1 byte, return 2 bytes - needs the return expanded for X bytes
int sendByte_getBytes(unsigned char reg_2_read, int bytes_to_rx)
{
// transmit slave address and register to read
iic_tx_init();

__delay_cycles(1000);  

   PTxData = (unsigned char *)&reg_2_read;     // TX array start address

   TXByteCtr = sizeof reg_2_read;              // Load TX byte counter

   start_TX();
   //
   // receive requested bytes
   iic_rx_init();								// set RX interrupt

   __delay_cycles(1000);

   PRxData = (unsigned char *)RxBuffer;    	// rx buffer

   RXByteCtr = bytes_to_rx;     				// number of bytes to receive

   start_RX();
   //
   return ((int)RxBuffer[0] << 8) | (int)RxBuffer[1];  // currently only returning 2 bytes

}

// iic start transmitting
void start_TX(void)
{
UCB0CTL1 |= UCTR + UCTXSTT;             	// I2C TX, start condition

   __bis_SR_register(LPM0_bits + GIE);     	// Enter LPM0, enable interrupts
   __no_operation();                       	// Remain in LPM0 until all data
                                           	// is TX'd
   while (UCB0CTL1 & UCTXSTP);             	// Ensure stop condition got sent
}

// iic restart and receive
void start_RX(void)
{
while (UCB0CTL1 & UCTXSTP);             	// wait for stop

   UCB0CTL1 &= ~UCTR;                      	// restart, set as receiver
   UCB0CTL1 |= UCTXSTT;                    	// start condition

   __bis_SR_register(LPM0_bits + GIE);

   while (UCB0CTL1 & UCTXSTP);
}
// interrupt pragma is defined in grace
void iic_TX_isr(void)
{
if (TXByteCtr)                          // Check TX byte counter
   {
     UCB0TXBUF = *PTxData++;               // Load TX buffer
     TXByteCtr--;                          // Decrement TX byte counter
   }
   else
   {
     UCB0CTL1 |= UCTXSTP;                  // I2C stop condition
     IFG2 &= ~UCB0TXIFG;                   // Clear USCI_B0 TX int flag
   }  
}
// interrupt pragma is defined in grace
void iic_RX_isr(void)
{	
RXByteCtr--;                            // Decrement RX byte counter
   if (RXByteCtr)
   {
   	P1OUT ^= 0x10;
     *PRxData++ = UCB0RXBUF;               // Move RX data to address PRxData
     if (RXByteCtr == 1)                   // Only one byte left?
       UCB0CTL1 |= UCTXSTP;                // Generate I2C stop condition
   }
   else
   {
     *PRxData = UCB0RXBUF;                 // Move final RX data to PRxData
   }
}

// tx function borrowed from TI's virtual_com_cmds.c
void TXString( char* string, int length )
{
 int pointer;
 for( pointer = 0; pointer < length; pointer++)
 {
   volatile int i;
   UCA0TXBUF = string[pointer];
   while (!(IFG2&UCA0TXIFG));              // USCI_A0 TX buffer ready?
 }
}

// timer A isr is simply toggling activity light for now.
// future pwm functions to go here
void timer_A_ISR(void)
{
P1OUT ^= BIT0;	
}

 

 

Excuse me, but where is the zip file?

[gwdeveloper 275]

Here it is...

bmp085_2553.zip

[matbhe 0]

Hi

Can anyone explain why the reading of the sensor data requires this ultralong delays?

* __delay_cycles(200000) -> Why wait 200ms?

According to the sensor specification the wait should be at least 5ms?
I'd like to make at least 10 measurements per second...

Thanks for an answer
Best Regards

Matthias

[semicolo 39]

200000 cycles that's 12.5ms at 16MHz, 200ms at 1MHz.

[matbhe 0]

Hello semicolo

 

Thanks for your answer. I assumed that my cpu is running @ 1mhz...

I've tested the cpu speed with a blinking led - test:

__delay_cycles(2000000) = 1 sec

So my CPU is running at 2mhz ... (16mhz - Divider = 8).

How can i speed up the I2C communication ..?

[gwdeveloper 275]

I couldn't get this to run any faster on the Launchpad for some reason. Move it over to the F2274, FR5739 or F5529 and all the delays can be removed and run at full speed. At the time, I didn't need a faster sampling rate so didn't look much further into it.

 

Sorry for any delayed responses on my part.

[supamas 2]

 

 

CCS was complaining about the Grace file.  Was there any special configurations I needed to see the Grace set up?  Specifically I wanted to see the TX interrupt functions.  I'm using the same MSP430 2553 chip and BMP085 for a project of mine and was using your code to compare against what I thought I understood.  I've downloaded your files but couldn't configure the Grace files correctly so that it would compile for me.

 

Thanks for your help!

[gwdeveloper 275]

@@supamas The TX and RX ISR functions are both included in the main.c file.  The grace file is just a configuration for the hardware.  It directs the IV to iic_RX_isr() and iic_TX_isr().

 

Can you be more specific with the error you are getting?