Spent the day getting two Tbolts I got off flea-bay up and running. Fun! Got to know my way around Lady Heather and learned a few more things about time/freq sources.
One of these units appears to have an onboard temp sensor that is dead - the temp just reads -55.0C all the time. This is the little Maxim/DallasDS1620 chip, which I can replace, but I had a few questions first. 1. I'm presuming that this isn't used for any of the oven temp control loop, and that its OK to run the unit as is. I can't imagine it would be and the DAC control voltage for the OCXO is not in runaway for a hot oven. 2. Anyone had this fail on a unit before? Seems kinda odd, as these little things are in everything and are ususally pretty robust. 3. I hooked up a logic analyzer to it, and there's data going back and forth between it and the microcontroller, which surprised me, as I thought it would be totally dead (but maybe this is just the microcontroller polling it to send back data?). I can't make sense of the data that I see. Just for my knowledge - Dallas 3 wire is more or less SPI right? I think there are a few differences for this chip - 9 bit word, trailing edge clock, and active high on the reset line. Anyone else ever looked at the data exchange with this device? Anything else I should know? I'm just trying to verify that it is indeed the DS1620 and not something else. Brent _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
