After 65 ms delay,
now, i want to read the data from location 2 and 3 of srf08.
can u tell me, how can i read these two locations??
Thanks
____________ _________ _________ __
From: this_ip_address
To: lpc2000@yahoogroups .com
Sent: Friday, 20 March, 2009 11:48:55 PM
Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
Yes, sounds OK. Now after 65 ms timeout you should READ (ADDRESS+R) the device.
Two bytes (in big endian) should tell you the range.
--- In lpc2000@yahoogroups .com, Viren Dobariya wrote: >
> hi,
> in my interrupt routine of srf08,
> 1)in the case 0x08: i am writing 0xE0(I2cAddress of srf08)
>
> 2)in the case 0x18: i am writing 0x00(reg addr of srf08)
> 3)in the case 0x28: i am writing 0x51(to define range)
> and I2CONSET = 0X10 (stop condition)
>
> so,i move out from interrupt routine.
> now i generate delay of 65ms using timer,but it is outside the i2c interrupt
routine..
> uptil now is it ok??
> please tell me,so i can go ahead.
> datasheet of srf08 is attached.
>
> thanks
>
> ____________ _________ _________ __
> From: this_ip_address
> To: lpc2000@yahoogroups .com
> Sent: Friday, 20 March, 2009 12:47:59 AM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> I really don't have time to debug your code, but it looks to me
> that your I2C states screwed up. Roghly, this thing should work
> like below. You should see states in this sequence. If not
> something went wrong. You need an additional timer interrupts
> to (1) define ranging frequency and (2) define ranging time interval
> on state 5.
>
> 1. State 0x00
> Prepare I2C to master transmitter mode.
> Issue start condition.
>
> 2. State 0x08
> Send ADDRESS+W
>
> 3.. State 0x18
> Write register address - 0 in simplest case.
>
> 4. State 0x28
> Write command. Indicate end of data
>
> 5.. Wait for ranging complete
> This depends on gain and ranging registers.
> Default 65 ms. If you try to read before sonar finished
> ranging, you will get I2C error.
>
> 6. You should be in master read mode. Issue START.
>
> 7. State 0x10
> Send ADDRESS+R
>
> 8. State 0x40
> Response started. Send ACK
>
> 9. State 0x50
> First byte
>
> 10. State 0x58
> Second byte. Stop. Return result to user.
>
> 11. Timeout before next ranging.
> Go to 1.
>
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> > i am using keil uvision3.
> > i am using lpc21xx.h provided by keil compiler
> > yes i have logic analayzer.
> > no, i never tried eeprom of i2c.how can i use it??
> >
> > data sheet of srf08 is attached with this mail
> >
> > thanks
> >
> >
> >
> >
> > ____________ _________ _________ __
> > From: donhamilton2002
> > To: lpc2000@yahoogroups .com
> > Sent: Wednesday, 18 March, 2009 5:59:21 PM
> > Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> >
> >
> > --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> > >
> > > hi,
> > > see the code of sfr08..
> > > and guide me.
> >
> > What compiler are you using ?
> >
> > What ..h files are you using ?
> >
> > What exactly are you seeing ?
> >
> > Do you have a O'scope or logic analyzer ?
> >
> > Have you tried an I2C EEPROM ?
> >
> > Do you have a data sheet for the sft08 ?
> > ( please link to it )
> >
> > don
> >
> >
> >
> >
> >
> > Unlimited freedom, unlimited storage. Get it now, on http://help.
yahoo.com/ l/in/yahoo/ mail/yahoomail/ tools/tools- 08.html/
> >
> >
> > Add more friends to your messenger and enjoy! Go to http://messenger.
yahoo.com/ invite/
>
>
>
Add more friends to your messenger and enjoy! Go to http://messenger. yahoo.com/
invite/
--- In l..., Viren Dobariya wrote: >
> After 65 ms delay,
> now, i want to read the data from location 2 and 3 of srf08.
> can u tell me, how can i read these two locations??
>
> Thanks
The problem with the SRF08 and I2C in general is that it is time consuming to
write the code. Nobody is going to do that for you.
There are examples all over the Internet but they are probably not specific to
the LPC2138.
You may find the I2C code in jc wren's sample code useful:
www.jcwren.com/arm It is for the LPC2148 so it will probably work. But it
isn't specific to the SRF08.
There is example code, directly to the point of reading distance using the SRF08
but it isn't for an ARM. Nevertheless, you can adapt it if you don't
mind using polled code. See http://www.bdmicro.com/code/srf08/ It is SPECIFIC
to what you are trying to do.
After 65 ms delay,
now, i want to read the data from location 2 and 3 of srf08.
can u tell me, how can i read these two locations??
Thanks
________________________________
From: this_ip_address
To: l...
Sent: Friday, 20 March, 2009 11:48:55 PM
Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
Yes, sounds OK. Now after 65 ms timeout you should READ (ADDRESS+R) the device.
Two bytes (in big endian) should tell you the range.
--- In lpc2000@yahoogroups .com, Viren Dobariya wrote: >
> hi,
> in my interrupt routine of srf08,
> 1)in the case 0x08: i am writing 0xE0(I2cAddress of srf08)
>
> 2)in the case 0x18: i am writing 0x00(reg addr of srf08)
> 3)in the case 0x28: i am writing 0x51(to define range)
> and I2CONSET = 0X10 (stop condition)
>
> so,i move out from interrupt routine.
> now i generate delay of 65ms using timer,but it is outside the i2c interrupt
routine.
> uptil now is it ok??
> please tell me,so i can go ahead.
> datasheet of srf08 is attached.
>
> thanks
>
> ____________ _________ _________ __
> From: this_ip_address
> To: lpc2000@yahoogroups .com
> Sent: Friday, 20 March, 2009 12:47:59 AM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> I really don't have time to debug your code, but it looks to me
> that your I2C states screwed up. Roghly, this thing should work
> like below. You should see states in this sequence. If not
> something went wrong. You need an additional timer interrupts
> to (1) define ranging frequency and (2) define ranging time interval
> on state 5.
>
> 1. State 0x00
> Prepare I2C to master transmitter mode.
> Issue start condition.
>
> 2. State 0x08
> Send ADDRESS+W
>
> 3. State 0x18
> Write register address - 0 in simplest case.
>
> 4. State 0x28
> Write command. Indicate end of data
>
> 5.. Wait for ranging complete
> This depends on gain and ranging registers.
> Default 65 ms. If you try to read before sonar finished
> ranging, you will get I2C error.
>
> 6. You should be in master read mode. Issue START.
>
> 7. State 0x10
> Send ADDRESS+R
>
> 8. State 0x40
> Response started. Send ACK
>
> 9. State 0x50
> First byte
>
> 10. State 0x58
> Second byte. Stop. Return result to user.
>
> 11. Timeout before next ranging.
> Go to 1.
>
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> > i am using keil uvision3.
> > i am using lpc21xx.h provided by keil compiler
> > yes i have logic analayzer.
> > no, i never tried eeprom of i2c.how can i use it??
> >
> > data sheet of srf08 is attached with this mail
> >
> > thanks
> >
> >
> >
> >
> > ____________ _________ _________ __
> > From: donhamilton2002
> > To: lpc2000@yahoogroups .com
> > Sent: Wednesday, 18 March, 2009 5:59:21 PM
> > Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> >
> >
> > --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> > >
> > > hi,
> > > see the code of sfr08..
> > > and guide me.
> >
> > What compiler are you using ?
> >
> > What ..h files are you using ?
> >
> > What exactly are you seeing ?
> >
> > Do you have a O'scope or logic analyzer ?
> >
> > Have you tried an I2C EEPROM ?
> >
> > Do you have a data sheet for the sft08 ?
> > ( please link to it )
> >
> > don
> >
> >
> >
> >
> >
> > Unlimited freedom, unlimited storage. Get it now, on http://help.
yahoo.com/ l/in/yahoo/ mail/yahoomail/ tools/tools- 08.html/
> >
> >
> > Add more friends to your messenger and enjoy! Go to http://messenger.
yahoo.com/ invite/
>
>
>
Yes, sounds OK. Now after 65 ms timeout you should READ (ADDRESS+R) the device.
Two bytes (in big endian) should tell you the range.
--- In l..., Viren Dobariya wrote: >
> hi,
> in my interrupt routine of srf08,
> 1)in the case 0x08: i am writing 0xE0(I2cAddress of srf08)
>
> 2)in the case 0x18: i am writing 0x00(reg addr of srf08)
> 3)in the case 0x28: i am writing 0x51(to define range)
> and I2CONSET = 0X10 (stop condition)
>
> so,i move out from interrupt routine.
> now i generate delay of 65ms using timer,but it is outside the i2c interrupt
routine.
> uptil now is it ok??
> please tell me,so i can go ahead.
> datasheet of srf08 is attached.
>
> thanks
>
> ________________________________
> From: this_ip_address
> To: l...
> Sent: Friday, 20 March, 2009 12:47:59 AM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> I really don't have time to debug your code, but it looks to me
> that your I2C states screwed up. Roghly, this thing should work
> like below. You should see states in this sequence. If not
> something went wrong. You need an additional timer interrupts
> to (1) define ranging frequency and (2) define ranging time interval
> on state 5.
>
> 1. State 0x00
> Prepare I2C to master transmitter mode.
> Issue start condition.
>
> 2. State 0x08
> Send ADDRESS+W
>
> 3. State 0x18
> Write register address - 0 in simplest case.
>
> 4. State 0x28
> Write command. Indicate end of data
>
> 5. Wait for ranging complete
> This depends on gain and ranging registers.
> Default 65 ms. If you try to read before sonar finished
> ranging, you will get I2C error.
>
> 6. You should be in master read mode. Issue START.
>
> 7. State 0x10
> Send ADDRESS+R
>
> 8. State 0x40
> Response started. Send ACK
>
> 9. State 0x50
> First byte
>
> 10. State 0x58
> Second byte. Stop. Return result to user.
>
> 11. Timeout before next ranging.
> Go to 1.
>
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> > i am using keil uvision3.
> > i am using lpc21xx.h provided by keil compiler
> > yes i have logic analayzer.
> > no, i never tried eeprom of i2c.how can i use it??
> >
> > data sheet of srf08 is attached with this mail
> >
> > thanks
> >
> >
> >
> >
> > ____________ _________ _________ __
> > From: donhamilton2002
> > To: lpc2000@yahoogroups .com
> > Sent: Wednesday, 18 March, 2009 5:59:21 PM
> > Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> >
> >
> > --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> > >
> > > hi,
> > > see the code of sfr08..
> > > and guide me.
> >
> > What compiler are you using ?
> >
> > What ..h files are you using ?
> >
> > What exactly are you seeing ?
> >
> > Do you have a O'scope or logic analyzer ?
> >
> > Have you tried an I2C EEPROM ?
> >
> > Do you have a data sheet for the sft08 ?
> > ( please link to it )
> >
> > don
> >
> >
> >
> >
> >
> > Unlimited freedom, unlimited storage. Get it now, on http://help.
yahoo.com/ l/in/yahoo/ mail/yahoomail/ tools/tools- 08.html/
> >
> >
> >
>
> Add more friends to your messenger and enjoy! Go to
http://messenger.yahoo.com/invite/
>
>
>
Reply by Viren Dobariya●March 20, 20092009-03-20
hi,
in my interrupt routine of srf08,
1)in the case 0x08: i am writing 0xE0(I2cAddress of srf08)
2)in the case 0x18: i am writing 0x00(reg addr of srf08)
3)in the case 0x28: i am writing 0x51(to define range)
and I2CONSET = 0X10 (stop condition)
so,i move out from interrupt routine.
now i generate delay of 65ms using timer,but it is outside the i2c interrupt
routine.
uptil now is it ok??
please tell me,so i can go ahead.
datasheet of srf08 is attached.
thanks
________________________________
From: this_ip_address
To: l...
Sent: Friday, 20 March, 2009 12:47:59 AM
Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
I really don't have time to debug your code, but it looks to me
that your I2C states screwed up. Roghly, this thing should work
like below. You should see states in this sequence. If not
something went wrong. You need an additional timer interrupts
to (1) define ranging frequency and (2) define ranging time interval
on state 5.
1. State 0x00
Prepare I2C to master transmitter mode.
Issue start condition.
2. State 0x08
Send ADDRESS+W
3. State 0x18
Write register address - 0 in simplest case.
4. State 0x28
Write command. Indicate end of data
5. Wait for ranging complete
This depends on gain and ranging registers.
Default 65 ms. If you try to read before sonar finished
ranging, you will get I2C error.
6. You should be in master read mode. Issue START.
7. State 0x10
Send ADDRESS+R
8. State 0x40
Response started. Send ACK
9. State 0x50
First byte
10. State 0x58
Second byte. Stop. Return result to user.
11. Timeout before next ranging.
Go to 1.
--- In lpc2000@yahoogroups .com, Viren Dobariya wrote: >
> i am using keil uvision3.
> i am using lpc21xx.h provided by keil compiler
> yes i have logic analayzer.
> no, i never tried eeprom of i2c.how can i use it??
>
> data sheet of srf08 is attached with this mail
>
> thanks
> ____________ _________ _________ __
> From: donhamilton2002
> To: lpc2000@yahoogroups .com
> Sent: Wednesday, 18 March, 2009 5:59:21 PM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> > hi,
> > see the code of sfr08..
> > and guide me.
>
> What compiler are you using ?
>
> What ..h files are you using ?
>
> What exactly are you seeing ?
>
> Do you have a O'scope or logic analyzer ?
>
> Have you tried an I2C EEPROM ?
>
> Do you have a data sheet for the sft08 ?
> ( please link to it )
>
> don
>
> Unlimited freedom, unlimited storage. Get it now, on http://help.
yahoo.com/ l/in/yahoo/ mail/yahoomail/ tools/tools- 08.html/
>
>
>
I really don't have time to debug your code, but it looks to me
that your I2C states screwed up. Roghly, this thing should work
like below. You should see states in this sequence. If not
something went wrong. You need an additional timer interrupts
to (1) define ranging frequency and (2) define ranging time interval
on state 5.
1. State 0x00
Prepare I2C to master transmitter mode.
Issue start condition.
2. State 0x08
Send ADDRESS+W
3. State 0x18
Write register address - 0 in simplest case.
4. State 0x28
Write command. Indicate end of data
5. Wait for ranging complete
This depends on gain and ranging registers.
Default 65 ms. If you try to read before sonar finished
ranging, you will get I2C error.
6. You should be in master read mode. Issue START.
7. State 0x10
Send ADDRESS+R
8. State 0x40
Response started. Send ACK
9. State 0x50
First byte
10. State 0x58
Second byte. Stop. Return result to user.
11. Timeout before next ranging.
Go to 1.
--- In l..., Viren Dobariya wrote: >
> i am using keil uvision3.
> i am using lpc21xx.h provided by keil compiler
> yes i have logic analayzer.
> no, i never tried eeprom of i2c.how can i use it??
>
> data sheet of srf08 is attached with this mail
>
> thanks
> ________________________________
> From: donhamilton2002
> To: l...
> Sent: Wednesday, 18 March, 2009 5:59:21 PM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> > hi,
> > see the code of sfr08.
> > and guide me.
>
> What compiler are you using ?
>
> What .h files are you using ?
>
> What exactly are you seeing ?
>
> Do you have a O'scope or logic analyzer ?
>
> Have you tried an I2C EEPROM ?
>
> Do you have a data sheet for the sft08 ?
> ( please link to it )
>
> don
>
> Unlimited freedom, unlimited storage. Get it now, on
http://help.yahoo.com/l/in/yahoo/mail/yahoomail/tools/tools-08.html/
>
>
>
Reply by Kenneth Crudup●March 19, 20092009-03-19
On Thu, 19 Mar 2009, Viren Dobariya wrote:
> i tried with
> I2SCLL = 188;
> I2SCLH = 188;
Be careful- I've seen a few lpc21xx.h files that have the wrong type for
these two registers (they're coded as either ushorts or uchars and they
need to be ulongs else the compiler writes 0 to the business end of the
register).
-Kenny
--
Kenneth R. Crudup Sr. SW Engineer, Scott County Consulting, Los Angeles
O: 3630 S. Sepulveda Blvd. #138, L.A., CA 90034-6809 (888) 454-8181
Reply by Viren Dobariya●March 19, 20092009-03-19
i am using keil uvision3.
i am using lpc21xx.h provided by keil compiler
yes i have logic analayzer.
no, i never tried eeprom of i2c.how can i use it??
data sheet of srf08 is attached with this mail
thanks
________________________________
From: donhamilton2002
To: l...
Sent: Wednesday, 18 March, 2009 5:59:21 PM
Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
--- In lpc2000@yahoogroups .com, Viren Dobariya wrote: >
> hi,
> see the code of sfr08.
> and guide me.
What compiler are you using ?
What .h files are you using ?
What exactly are you seeing ?
Do you have a O'scope or logic analyzer ?
Have you tried an I2C EEPROM ?
Do you have a data sheet for the sft08 ?
( please link to it )
but behavior of the sensor is same.
please check my i2ctransferbyte() function and sonar_call() function.
code is given below.
thanks
________________________________
From: this_ip_address
To: l...
Sent: Thursday, 19 March, 2009 2:20:03 AM
Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
Since you do not set explicitly APB divider, I assume it is
default 1/4 of CPU speed. Assuming CPU speed at 60 MHz,
if you want to get 40 kHz I2C, the divider should be 187.5:
40000 = (0.25*60000000) / (187.5 + 187.5)
I use SRF10 (suppose to be the same as SRF08) at 100kHz on LPC2368 and it works
OK (electrically) , but device itself is rather crappy. I did not check your
other code. Start with the correct dividers first.
--- In lpc2000@yahoogroups .com, Viren Dobariya wrote: >
> hi,
> see the code of sfr08.
> and guide me.
>
> Thanks
> viren
> //////////// ///****** ********* ********* *//////// ///////// /////////
///////
> unsigned char message[1] = {0x51};
> //unsigned char message1[1] = {0x01};
> //unsigned char messageIn[4] ;
> unsigned char *I2CData,
> I2Counter,
> I2CAddress,
> MemAddress,
> lock; //Define Function prototypes and Global
variables
> unsigned int data = 0;
> /*********** ********* ********* ********* ********* ********* ******/
> void I2CTransferByte( unsigned int I2CAddr,unsigned char MemAddr,unsigned char
count,...)
> {
> va_list ap;
> va_start(ap, count);
>
> while(lock == 1) //Wait for interrupt to
signal end of I2C activity
> {
> ;
> }
> lock = 1; //Set I2C bus as
active
>
> I2CAddress = I2CAddr; //Place address and
data in Globals
>
> to be used by the interrupt
> if(count >0)
> {
> I2CData = va_arg(ap,unsigned char *);
> }
> I2Counter = count;
> MemAddress = MemAddr;
> I2CONCLR = 0x000000FF; //Clear all I2C
settings
> I2CONSET = 0x00000040; //Enable the I2C
interface
> I2CONSET = 0x00000020; //Start condition
> va_end(ap);
> }
>
> /*********** ********* ********* ********* ********* ********* ******/
> void I2CISR (void) __irq //I2C interrupt routine
> {
> switch (I2STAT) //Read result code and
switch to next
>
> action
> {
> // Start and Send byte conditions
>
> case ( 0x08): //Start bit
> I2CONCLR = 0x20; //Clear start bit
> I2DAT = I2CAddress; //Send address and write
bit
> break;
>
> case ( 0x10): //Start bit
> I2CONCLR = 0x20; //Clear start bit
> I2DAT = I2CAddress; //Send address and write
bit
> break;
>
> case (0x18): //Slave address+W, ACK
> I2DAT = MemAddress; //Write Mem,ory start
address to tx register
> break;
>
> case (0x20): //Salve address +W, Not
ACK
> I2DAT = I2CAddress; //Resend address and
write bi
> break;
>
> case (0x28):
> if(I2Counter- ->0) //Data sent, Ack
> {
> I2DAT = *I2CData; //Write data to tx
register
> I2CData++;
> }
> else
> {
> I2CONSET = 0x10; //Stop condition
> lock = 0; //Signal end of I2C
activity
> }
> break;
>
> case (0x30) : //Data sent, NOT
Ack
> I2DAT = *I2CData; //Write data to tx
register
> break;
> //Receive byte conditions
>
> case (0x40) : //Slave Address +R,
ACK
> I2CONSET = 0x04; //Enable ACK for data
byte
> break;
>
> case (0x48) : //Slave Address +R, Not
Ack
> I2CONSET = 0x20; //Resend Start
condition
> break;
>
> case (0x50) : //Data Received, ACK
> if(I2Counter- ->0)
> {
> to_hyper(I2DAT) ;
> data = I2DAT;
> //*I2CData = I2DAT;
> //I2CData++;
> }
> else
> {
> I2CONSET = 0x10; //Stop condition
> lock = 0; //Signal end of I2C
activity
> }
> break;
>
> case (0x58): //Data Received, Not
Ack
> I2CONSET = 0x20; // Resend Start
condition
> break;
>
> default :
> break;
>
> }
>
> I2CONCLR = 0x08; //Clear I2C interrupt
flag
> VICVectAddr = 0x00000000; //Clear interrupt in
>
> }
> /*********** ********* ********* ********* ********* ********* *********
***/
> void sonar_call(void)
> {
> unsigned int data1 = 0;
> unsigned int i= 0;
> I2CTransferByte( 0xE0,0x00, 1,message) ; //write data to
the I2C Memory
>
> //////////// // delay ems //////////// ///////// //////
>
> I2CTransferByte( 0xE0,0x02, 1); //write data to the I2C
Memory
> I2CTransferByte( 0xE1,0x02, 2); //read higher byte
> I2CTransferByte( 0xE1,0x03, 1); //read lower data
>
> }
>
> /*********** ********* ********* ********* ********* ********* *********
**/
> int main(void)
> {
>
> lock = 0; //Initilise the lock
flag
>
> VICVectCntl1 = 0x00000029; //select a priority slot
for a given interrupt
> VICVectAddr1 = (unsigned)I2CISR; //pass the address of the
IRQ into the VIC slot
> VICIntEnable = 0x00000200; //enable interrupt
>
> PINSEL0 = 0x55; //Switch GPIO to I2C
pins
>
> I2SCLH = 1875; //Set bit rate =
40khz
> I2SCLL = 1875;
>
> while(1)
> {
> sonar_call() ;
>
> }
> }
> ____________ _________ _________ __
> From: donhamilton2002
> To: lpc2000@yahoogroups .com
> Sent: Tuesday, 17 March, 2009 5:05:14 PM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> >
> > hi,
> > i have interface srf08-ultrasonic sensor with i2c bus of lpc2138.but i am
facing communication problem with this interfacing. can anybody give me sample
code of srf08-ultrasonic sensor with lpc21xx??
> >
> > thanks
> > viren
>
> It would be much easier to post your code here.
>
> I am sure you did something wrong in your code, lets see it..
>
> don
>
> Add more friends to your messenger and enjoy! Go to http://messenger.
yahoo.com/ invite/
>
>
>
Since you do not set explicitly APB divider, I assume it is
default 1/4 of CPU speed. Assuming CPU speed at 60 MHz,
if you want to get 40 kHz I2C, the divider should be 187.5:
40000 = (0.25*60000000) / (187.5 + 187.5)
I use SRF10 (suppose to be the same as SRF08) at 100kHz on LPC2368 and it works
OK (electrically), but device itself is rather crappy. I did not check your
other code. Start with the correct dividers first.
--- In l..., Viren Dobariya wrote: >
> hi,
> see the code of sfr08.
> and guide me.
>
> Thanks
> viren
> ///////////////*************************/////////////////////////////////
> unsigned char message[1] = {0x51};
>
>
> //unsigned char message1[1] = {0x01};
> //unsigned char messageIn[4];
> unsigned char *I2CData,
> I2Counter,
> I2CAddress,
> MemAddress,
> lock; //Define Function prototypes and Global
variables
> unsigned int data = 0;
> /**************************************************************/
> void I2CTransferByte(unsigned int I2CAddr,unsigned char MemAddr,unsigned char
count,...)
> {
> va_list ap;
> va_start(ap,count);
>
> while(lock == 1) //Wait for interrupt to
signal end of I2C activity
> {
> ;
> }
> lock = 1; //Set I2C bus as
active
>
> I2CAddress = I2CAddr; //Place address and
data in Globals
>
> to be used by the interrupt
> if(count >0)
> {
> I2CData = va_arg(ap,unsigned char *);
> }
> I2Counter = count;
> MemAddress = MemAddr;
> I2CONCLR = 0x000000FF; //Clear all I2C
settings
> I2CONSET = 0x00000040; //Enable the I2C
interface
> I2CONSET = 0x00000020; //Start condition
> va_end(ap);
> }
>
> /**************************************************************/
> void I2CISR (void) __irq //I2C interrupt routine
> {
> switch (I2STAT) //Read result code and
switch to next
>
> action
> {
> // Start and Send byte conditions
>
> case ( 0x08): //Start bit
> I2CONCLR = 0x20; //Clear start bit
> I2DAT = I2CAddress; //Send address and write
bit
> break;
>
> case ( 0x10): //Start bit
> I2CONCLR = 0x20; //Clear start bit
> I2DAT = I2CAddress; //Send address and write
bit
> break;
>
> case (0x18): //Slave address+W, ACK
> I2DAT = MemAddress; //Write Mem,ory start
address to tx register
> break;
>
> case (0x20): //Salve address +W, Not
ACK
> I2DAT = I2CAddress; //Resend address and
write bi
> break;
>
> case (0x28):
> if(I2Counter-->0) //Data sent, Ack
> {
> I2DAT = *I2CData; //Write data to tx
register
> I2CData++;
> }
> else
> {
> I2CONSET = 0x10; //Stop condition
> lock = 0; //Signal end of I2C
activity
> }
> break;
>
> case (0x30) : //Data sent, NOT
Ack
> I2DAT = *I2CData; //Write data to tx
register
> break;
>
>
> //Receive byte conditions
>
> case (0x40) : //Slave Address +R,
ACK
> I2CONSET = 0x04; //Enable ACK for data
byte
> break;
>
> case (0x48) : //Slave Address +R, Not
Ack
> I2CONSET = 0x20; //Resend Start
condition
> break;
>
> case (0x50) : //Data Received, ACK
> if(I2Counter-->0)
> {
> to_hyper(I2DAT);
> data = I2DAT;
> //*I2CData = I2DAT;
> //I2CData++;
> }
> else
> {
> I2CONSET = 0x10; //Stop condition
> lock = 0; //Signal end of I2C
activity
>
>
> }
> break;
>
> case (0x58): //Data Received, Not
Ack
> I2CONSET = 0x20; // Resend Start
condition
> break;
>
> default :
> break;
>
> }
>
> I2CONCLR = 0x08; //Clear I2C interrupt
flag
> VICVectAddr = 0x00000000; //Clear interrupt in
>
> }
> /********************************************************************/
> void sonar_call(void)
> {
> unsigned int data1 = 0;
> unsigned int i= 0;
> I2CTransferByte(0xE0,0x00,1,message); //write data to the
I2C Memory
>
> ////////////// delay ems ///////////////////////////
>
> I2CTransferByte(0xE0,0x02,1); //write data to the I2C Memory
> I2CTransferByte(0xE1,0x02,2); //read higher byte
> I2CTransferByte(0xE1,0x03,1); //read lower data
>
> }
>
> /*******************************************************************/
> int main(void)
> {
>
> lock = 0; //Initilise the lock
flag
>
> VICVectCntl1 = 0x00000029; //select a priority slot
for a given interrupt
> VICVectAddr1 = (unsigned)I2CISR; //pass the address of the
IRQ into the VIC slot
> VICIntEnable = 0x00000200; //enable interrupt
>
> PINSEL0 = 0x55; //Switch GPIO to I2C
pins
>
> I2SCLH = 1875; //Set bit rate =
40khz
> I2SCLL = 1875;
>
> while(1)
> {
> sonar_call();
>
> }
> }
> ________________________________
> From: donhamilton2002
> To: l...
> Sent: Tuesday, 17 March, 2009 5:05:14 PM
> Subject: [lpc2000] Re: regarding srf08(ultrasonic sensor) comm prob with
lpc2138
> --- In lpc2000@yahoogroups .com, Viren Dobariya
wrote:
> >
> >
> > hi,
> > i have interface srf08-ultrasonic sensor with i2c bus of lpc2138.but i am
facing communication problem with this interfacing. can anybody give me sample
code of srf08-ultrasonic sensor with lpc21xx??
> >
> > thanks
> > viren
>
> It would be much easier to post your code here.
>
> I am sure you did something wrong in your code, lets see it..
>
> don
>
> Add more friends to your messenger and enjoy! Go to
http://messenger.yahoo.com/invite/
>
>
>
