2 Replies Latest reply on Mar 29, 2017 11:06 PM by alku_1601796

    How many ADC inputs is possible on PSoC6?

      I'm making a small project on PSoC 5LP - capacitive sensing controller, mostly for old IBM keyboards (though other capacitive switches should not be much of a problem to support).


      Here's the source if anyone is interested: https://github.com/dmaone/CommonSense


      Almost got to release and BAM, PSoC6 is announced


      I'm not using capsense module - it's just too slow. I use scanning ADC. To make things faster, I drive the short side of the matrix, and scanning long one. Less time spent waiting for the matrix to charge that way.

      For beamsprings, that requires 23 ADC inputs.


      So, the question is - will PSoC6 support normal AMUX, or it will sport a crippled version with 8 unmovable SARMUX pins, like in PSoC4?


      Bluetooth beamspring is a holy grail of mechanical keyboards community, and making a single-chip solution would be awesome (bonus points if the same chip would also supervise battery charging - right now it looks like a separate IC is needed just for that).

        • 1. Re: How many ADC inputs is possible on PSoC6?



          The SAR ADC architecture in PSoC 6 is similar to what we have in PSoC 4 but with improved sampling rate (2 Msps vs 1 Msps). So, it again provides only 8 pins that directly connect to the SAR Sequencer.


          That said, I would like to point out a feature that you probably might have missed (even in PSoC 4). The SAR ADC is capable of taking inputs from the Analog Muxes (AMUX-A and AMUX-B) that run across the chip. Thus enabling the connection of pretty much all the IOs to the SAR MUX. This ability combined with a small sequencing logic (for sequencing the AMUX inputs) implemented in the UDBs along with DMAs or firmware using interrupts should be able to serve the 23 input need. This I believe should be possible in PSoC 4 as well. If you are interested, you can raise a tech support case and our support team will be more than glad to assist you further on this.


          And for battery charging supervision, I believe you require an ADC channel (may be buffered) for voltage and another ADC channel with a TIA for monitoring current. If this is the requirement, then PSoC 6 should be able to support this with its Op-amps and ADC.


          Let me know, if the above answer clarifies your question.



          Meenakshi Sundaram R

          • 2. Re: How many ADC inputs is possible on PSoC6?

            Oh, what a pleasant surprise.

            Completely missed that. So SARMUX is not instead of AMUXes, but in addition to. Wonderful news!


            Looks like when PSoC6 comes out with BT _and_ USB, that would be one perfect device for me.