I guess they never thought someone would want to use two SHT21's in the same circuit.
They should have used the two NC pins for setting the address, like microchip does. Matt. On Apr 4, 5:32 am, "Serdar K." <[email protected]> wrote: > But that address is same for all SHT21 s. Everyone has an unique serial ID > also, but that has nothing to do with I2C protocol. > > 2011/4/4 mattschinkel <[email protected]> > > > > > > > from SHT21 datasheet: > > > Sending a Command > > > After sending the Start condition, the subsequent I2C > > header consists of the 7-bit I2C device address ‘1000’000’ > > and an SDA direction bit (Read R: ‘1’, Write W: ‘0’). > > > On Apr 4, 4:52 am, Sebastien Lelong <[email protected]> > > wrote: > > > If you can access the device using i2c protocol, it inevitably has a i2c > > > address as it's inner part of the procotol itself. > > > > Cheers, > > > Seb > > > > 2011/4/4 Serdar K. <[email protected]> > > > > > The thing is, i can't find any data on the datasheet of SHT21 to > > address > > > > them. > > > > It has an ID, and you can read the ID, but no specific I2C address, and > > no > > > > match mechanism is shown for the SHT21 ID as far as i could see. > > > > > 2011/4/4 mattschinkel <[email protected]> > > > > >> Why do you need 2 I2C ports? I2C is addressable and you may put more > > > >> then one device on one I2C port. > > > > >> Matt. > > > > >> On Apr 4, 3:13 am, "Serdar K." <[email protected]> wrote: > > > >> > 2011/3/27 mattschinkel <[email protected]> > > > > >> > > > > MSSP2 will require a separate SPI library, or a constant in > > the > > > >> > > > > current lib to choose between 1 and 2. > > > > >> > > > OK. I guess this is the same for serial hardware with RX1/TX2 > > and > > > >> > > RX2/TX2. > > > >> > > > Preprocessor to the rescue ? > > > > >> > > Someday we all need to decide on either using the same library > > twice, > > > >> > > or create a 2nd library. A preprocessor doesn't seem like the > > right > > > >> > > solution. Again, pointers would be nice. > > > > >> > I even do need it now. > > > >> > Not only to decide which module, registers, i need to use seperate > > ports > > > >> for > > > >> > two different > > > >> > devices simultaneously. > > > > >> > My need for now is to select different two similar (better > > equivalent) > > > >> i2c > > > >> > devices. > > > >> > I use software I2C, my work is to be easier in this way, but it > > isn't. > > > >> Or i > > > >> > haven't enough knowledge about JAL. > > > > >> > .......................... > > > >> > ..... > > > > >> > var byte I2C_PortIndex = 1 > > > > >> > ............................. > > > > >> > --- > > > //============================================================================== > > > >> > --- //Initializes the ports for I2C interface > > > >> > --- > > > //============================================================================== > > > >> > procedure i2c_initialize() is > > > >> > --- > > > //============================================================================== > > > > >> > if (I2C_PortIndex == 1) then > > > >> > i2c_SHT21_sda_direction = low; // Set port as > > output > > > >> for > > > >> > configuration > > > >> > i2c_SHT21_scl_direction = low; // Set port as > > output > > > >> for > > > >> > configuration > > > > >> > i2c_SHT21_sda = low; // Set SDA level as low for output > > mode > > > >> > i2c_SHT21_scl = low; // Set SCL level as low for output > > mode > > > > >> > i2c_SHT21_sda_direction = high; // I2C-bus idle mode > > SDA > > > >> > released (input) > > > >> > i2c_SHT21_scl_direction = high; // I2C-bus idle mode > > SCL > > > >> > released (input) > > > >> > end if > > > > >> > if ( I2C_PortIndex == 2 ) then > > > >> > i2c_SHT21_sda_direction_2 = low; // Set port as > > output > > > >> for > > > >> > configuration > > > >> > i2c_SHT21_scl_direction_2 = low; // Set port as > > output > > > >> for > > > >> > configuration > > > > >> > i2c_SHT21_sda_2 = low; // Set SDA level as low for > > output > > > >> mode > > > >> > i2c_SHT21_scl_2 = low; // Set SCL level as low for > > output > > > >> mode > > > > >> > i2c_SHT21_sda_direction_2 = high; // I2C-bus idle > > mode > > > >> SDA > > > >> > released (input) > > > >> > i2c_SHT21_scl_direction_2 = high; // I2C-bus idle > > mode > > > >> SCL > > > >> > released (input) > > > >> > end if > > > > >> > end procedure > > > > >> > ..... > > > > >> > .... > > > > >> > This is only the shortest procedure. > > > > >> > This perspective is not tested OK yet, but i haven't be able to find > > > >> another > > > >> > way. > > > >> > And all procedures are multiplied like this by the sensor count > > (and > > > >> also > > > >> > the code size is multiplied). > > > > >> > If i could be able to dynamically change the alias to point another > > > >> > register, this would never be a problem. > > > > >> > > Maybe you can ask William if you can add a optional constant for > > > >> > > choosing what SPI port to use (after you test with ENC28J60 of > > > >> > > course). > > > > >> > > Matt. > > > > >> > > -- > > > >> > > You received this message because you are subscribed to the Google > > > >> Groups > > > >> > > "jallib" group. > > > >> > > To post to this group, send email to [email protected]. > > > >> > > To unsubscribe from this group, send email to > > > >> > > [email protected]. > > > >> > > For more options, visit this group at > > > >> > >http://groups.google.com/group/jallib?hl=en. > > > > >> > -- > > > >> > *Serdar KIZILTOPRAK > > > >> > Intelligence **Technology Systems > > > >> > [email protected]http://www.its3k.com > > > >> > +90(216) 518 15 00* > > > >> > **- Hide quoted text - > > > > >> > - Show quoted text - > > > > >> -- > > > >> You received this message because you are subscribed to the Google > > Groups > > > >> "jallib" group. > > > >> To post to this group, send email to [email protected]. > > > >> To unsubscribe from this group, send email to > > > >> [email protected]. > > > >> For more options, visit this group at > > > >>http://groups.google.com/group/jallib?hl=en. > > > > > -- > > > > *Serdar KIZILTOPRAK > > > > Intelligence **Technology Systems > > > > [email protected] > > > >http://www.its3k.com > > > > > +90(216) 518 15 00 > > > > * > > > > **- Hide quoted text - > > > > - Show quoted text - > > > -- > > You received this message because you are subscribed to the Google Groups > > "jallib" group. > > To post to this group, send email to [email protected]. > > To unsubscribe from this group, send email to > > [email protected]. > > For more options, visit this group at > >http://groups.google.com/group/jallib?hl=en. > > -- > *Serdar KIZILTOPRAK > Intelligence **Technology Systems > [email protected]http://www.its3k.com > +90(216) 518 15 00* > **- Hide quoted text - > > - Show quoted text - -- You received this message because you are subscribed to the Google Groups "jallib" group. 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