> To follow up on this post: I missed > the i2c pullup on the same pin,
Speaking about pullups: Internal PIC pullups should do. They deliver at least 50µA, while the ds18b20 only requires 5µA. So, even if the PIC pullup is thought as being resistive, and the PIC is powered from 3.3V, it should suffice. In parasite power mode during conversion or eprom writes, a maximum of 1.5mA is required, which is easily supplied by a PIC by switching the pin to output, driving high. So I thought interfacing the ds18b20 to a PIC should only require some wires, no other components? And, even when powering with 5V, the pullup resistor can go as low as 1.2kOhm. During a conversion, max. 1.5mA are required. 5V-(1.5mA*1.2kOhm)=3.2V, which is above the minimum operating voltage. So, with a 1.2kOhm pullup parasite power could be possible, even without the "strong pullup" described in the datasheet? I can try when I have one of those, just had to write down my thoughts ;-) Greets, Kiste -- 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.
