On 05/27/2009 11:15 AM, Andre Prendel wrote: > Hi Hans, > > looking in the datasheet of the TMP421 sensor chip > > http://focus.ti.com/docs/prod/folders/print/tmp421.html, > > I saw the following addresses. > > TMP421 100 11xx > TMP422 100 11xx > TMP423A 100 1100 > TMP423B 100 1101 > > But the preliminary driver of your students uses 0x2a. > > /* Addresses to scan */ > static unsigned short normal_i2c[] = { 0x2a, I2C_CLIENT_END }; > > 0x2a == 010 1010b, right? > Right. > Do I misunderstand something? No, what my students did in there was wrong, they only put the address in there to which the sample I gave them is wired The addresses to scan should be: static unsigned short normal_i2c[] = { 0x1c, 0x1d, 0x1e, 0x1f, 0x2a, 0x4c, 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; But we better run those past Jean, to see if any of those are dangerous to scan by default, Jean ? > And what means the xx in the address of TMP421/422? This means that the address is configurable by hooking up the IC in different ways, see table 9 and 10 at page 17 of the data sheet. Regards, Hans
