• Humanoid posted an update 2 years, 9 months ago

    I have a question about the finger-tip sensors. I notice that the nervo break-out boards have the same 3 input pins as the servo ones (pos, neg and S). The finger sensors only have 2 wires for each. The circuit diagram looks like the 2 wires go to the positive and S pins only. Is this correct? If so do we ignore the ground pin? Is there anything else which has to be added apart from the ribbon to go to the nervo board attached breakout?
    Did someone mention additional resistors being required? The only resistors I have used are the ones on the nervo. I have added all of them but I thought they were only for the LEDs.

    • You need to order two SIP resistor_network they look like this:
      http://www.thedigitalshop.net/iccpix/sip-b-10.gif
      http://www.electronicshub.org/wp-content/uploads/2014/12/Network-Resistors.jpg
      The NervoBoard has the option to solder one at the sensor side.
      You need a 8-pin version (with seven resistors).
      I only don’t now which value you need to use.
      I hope some one els can share this info.

      The sensors are only connected to the 5V and the Signal.

      Regards,
      Marten

    • Hi, Marten.
      I understand now where to connect the SIP resistor. I note that there are type A and type B in those resistor networks. Is the one I need the type A? (isolated). I have been asking around but haven’t yet found anyone who knows or who knows which value I need. If you find out can you reply please?

      • Hi Humanoid,

        Can you measure for me the open value and the closed value from the sensor ?
        If I now these value’s, I can choice a SIP resistor value 🙂

        Thanks in advance…

        Regards,
        Marten

    • HI Marten.
      I will probably re-print the finger-tips tomorrow and start again as I’m not happy with them.
      I am trying to get the measurements you asked for but the numbers are changing continually – going radically up and down. I have attached the red and black to each wire in the finger and have tried with a couple of fingers where the tip moves okay.
      When the finger is untouched it says 1. which seems to usually be the default measurement when my meter is not doing anything.
      When I touch the majeur it goes between 2.0 and 19.00 all over the place then goes back to 1. It keeps changing again even when not touched. ????
      The thumb :
      when pressed fully goes to 0.06 and when not touched at all says 1. When it it pushed to just make a bit of contact it goes to 8.0, 7.0, 15.0, 14.0, 2.0, 10.0, 17.0, 14.0. Etc. It seems to settle around 0.76-0.66 when not touched. ???

      Middle finger (Majeur):
      Seems to hover up to 19.0 and all the way down to 9.0 when not touched. When pressed all the way in it down to 0.07 when pressed all the way in.

      The numbers seem to move around all over the place regardless of whether they are being touched.

      Ring finger: 1.45 (not pressed) to 0.3(when pressed). – Note: this sensor is a little hard to press as I think it might be a bit gluey.

      I don’t know what’s really happening here or whether that’s what’s supposed to happen. ;-/

      The only meter setting where I could get readings was 20M.
      Thanks for helping.
      -Humanoid