Heart rate sensor MAX30102

[richard]

LATC.1 for Data
LATC.2 for Clock

a recipe for failure in the making ?
use of LATx ports in "highlevel" commands is incorrect and will not work as expected

Is this the correct way to assign a constant value to the name?

a quick little exercise trying to compile this will reveal the differences between defines and constants

reg var byte'#define bite_me 5     ;try one or the other of these two or niether 
'bite_me con 5         ;                      "


REG_INTR_STATUS_1 con   $00
REG_INTR_STATUS_2 con   $01
REG_INTR_STATUS_2 con   $07
REG_INTR_STATUS_3 con   bite_me


define REG_INTR_ENABLE_1   $02
define REG_INTR_ENABLE_2  bite_me
define REG_INTR_ENABLE_2  1


#define REG_INTR_ENABLE_3   $02
#define REG_INTR_ENABLE_4  bite_me
#define REG_INTR_ENABLE_4  1


loopy:


reg =  bite_me
reg = REG_INTR_ENABLE_3 
reg = REG_INTR_ENABLE_1
reg = REG_INTR_STATUS_1


goto loopy

[astanapane]

Thanks for the reply.

do you mean that i cannot use the following format?

DataPin var LATC.1
ClockPin var LATC.2

[richard]

if that will become

I2CREAD DataPin, ClockPin, Control,{Address,}[Var{,Var...}]{,Label}

then yes that is not allowable and will cause difficult to determine bugs.
you have to remember pbp is ancient technology, latx registers did not exist when it was created
it never gets any significant updates

[astanapane]

It is a bit consfusing for me.

But i will try to figure it out.

My goal is to communicate with this heart sensor. First step is to send this command to light up the LED and then try to read the information needed.

I have tried this I2C ping program http://www.picbasic.co.uk/forum/showthread.php?t=20185, in order to see if the sensor responds with the ACK. (i though that the sensor was dead)

[richard]

this i2c sniffer will usually do the job

  
DEFINE I2C_SLOW 1    
      anselA=0        'dig i/o 
      ANSELC=0
      TRISC= %11111111
      TRISA= %11111110  


SCL                 var Portc.1                     ' I2C Clock  PortA.3
SDA                 var Portc.0                     ' I2C Data   PortA.2
I                   VAR BYTE  
addr                var byte
rd                   var byte

    porta.0=1
    DEFINE DEBUG_REG PORTA
    DEFINE DEBUG_BIT 0      ;  if not used for pwr  
    DEFINE DEBUG_BAUD 38400
    DEFINE DEBUG_MODE 0     
    pause 2000
    Debug "Start",13 ,10
   addr=0


for I = $02 to $fe step 2
I2Cread SDA,SCL,i,addr,[rd] ; or I2Cread SDA,SCL,i,[rd] ;
Debug "found addr ",#i , 13,10 
nak:
Next I
end

[astanapane]

thanks for the book.

on the other hand, i would like to continue with this project as it is important for me and the kids in school.

I have done the first attempt to communicate with the sensor but no luck.

Based on the Datasheet MAX30102, device address, or slave id: %1010111, consists of 7 bit, B7-B1,and the MSB-7 is transmitted first followed by the remaining bits. B0 is LSB which can be 0 if we write or 1 if we read.

Then again from the manual explains that for the first write operation, we send the slave id as the first byte!....followed by the register address byte and then one or more data.

From the PBP manual, and from this link http://www.picbasic.co.uk/forum/cont...-EEPROM-Part-1

It is clear that I2CWRITE and I2CREAD command takes care of the write or read bit, also for the ACK.



Now i have tried to send the following:

if PBP and command I2CWRITE takes care of the 8th bit then how could i manage to correspond it in the code.

i2cwrite sda,scl,%1010111,$04,error ' this is slave id cosnist of 7 bits.

If i send the above command nothing will happen, and the data line will be offset from the clock.



Now using the following code:

i2cwrite sda,scl,%10101110,$04,error

i get this on the scope:



then i tried the following:

i2cwrite sda,scl,%10101110,$04,error
pause 100
i2cwrite sda,scl,%10101110,$04,error

and the result on the scope: it looks strange again.