Hi Geert, Do you put resistors on the SDA and SCL on each i2c circuit on the bus, or only one pair on the "fox side ?" Thanks Best regards
--- In [email protected], "Geert Vancompernolle" <[EMAIL PROTECTED]> wrote: > > --- In [email protected], Thomas Treyer <Thomas@> wrote: > > > > Hi Geert, > > > > I am just wondering about your "construction", because I am designing > > the schematic for my hardware. Can you please explain, why you use > > the 100 Ohm series resistors? Are they necessary or are they used for > > debugging purposes? > > > > I have some doubts about pin 12 (EXT input). In the data sheet this > > pin has to be connected to either VSS or VDD. This input has high > > impedance. If you leave it open, strange things may occur. The signal > > level depends now on leakage current from the board and from the chip > > itself. In some instances it may result in a logical Low, in other > > circumstances it may be high. If this is the case, no A/D conversion > > will take place. Maybe this is the problem of gazoox22. For A/D > > conversion you need a clock, while you need no clock for D/A conversion. > > > > .................... > > Thomas Treyer > > Hi Thomas, > > The 100 Ohm resistors are there as "damping" resistors. It's a first > level of protection against ESD (high voltage spikes). > > About your second question: you're correct. I overlooked this, since > I'm using a breadboard and there are so many wires attached to the > board one can hardly see the "real" hardware. Sorry for the possible > misleading information... > > Only in case you choose to feed the clock externally, you have to > connect that pin to Vcc. Gnd otherwise... > > Best rgds, > > --Geert >
