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Sensors, Actuators, and Robotics » "custom" interface on ADC questions

March 24, 2010
by 6ofhalfdozen
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I recently inherited some microchip TC3400 ADC's. They seem to be a good choice for some simple ADC and thermocouple projects I plan to try. The only problem is that they have a "custom" style 2 wire interface, I am am not sure where to start in trying to figure out how to get them to talk with the nerdkit mcu. I read the post about the digital humidity sensor having a similar issue, but I didn't see any details about how the custom interface was dealt with. Back to the TC3400's. The datasheet goes over the specific clocking sequences to start/stop and read the data. They make decent sense, and I think I can handle the programming to toggle the pins as needed. The datasheet makes a brief mention of a 520kHz internal clock for the ADC, but no clear mention of data in/out communication speeds. It shows clocking diagrams but there are no clear measurable time units. So my questions:

  • does this imply that the clocking must be done at 520kHz?

  • or is the clocking open to whatever rate the mcu sends (below 520kHz?)?

  • has anyone here dealt with this style of ADC before?

any other thoughts, suggestions, or comments?

March 24, 2010
by BobaMosfet
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Actually, those clocking sequences tell you a lot more than you think :P They are your friends! How many pins does it have? I'll see if I can find a datasheet and look at it.

BM

March 24, 2010
by BobaMosfet
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I looked up the TC3400 datasheet. It uses a proprietary protocol called 'MicroPort'. However, the datasheet explains it.

BM

March 28, 2010
by 6ofhalfdozen
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Perhaps I was reading into the datasheet numbers a bit much. It looks like the clock pulses have a min of 75ns and max of 750ns, which gives a decent bit of room to work with. I will give it a few tries and see what I end up with. Any results good or bad, I will mention. thanks for the clarification.

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