5 Replies Latest reply on Aug 28, 2014 1:45 PM by DiegoV_Intel

    Working with Galileo (1st gen), servo motor, buttons and display

    eloher

      Hi everyone, I'm working on a project: I want to realize an automatic vehicles parking barrier with a real time counter of available parking spaces.

      I have a Galileo (1st gen) and I want to simulate the automatic barrier with a servo motor, that will be activated by two buttons (one for entering cars, the other for the exiting ones). The real time counter will be showed on a 7 segment display.

      I realized this schematic on Fritzing for now:

       

      10637840_10204516167688319_642657312_n.jpg

       

      My questions are:

      1) Is the schematic correct? Any suggestion on it?

      2) Will my servo motor (Tower Pro SG90 9G) work with Galileo?

       

      Thanks in advance!

        • 1. Re: Working with Galileo (1st gen), servo motor, buttons and display
          DiegoV_Intel

          Hi eloher,

           

          Your schematic looks good but I recommend you a few things:

           

          For the push buttons:

               I can see that one button provide a high level input and the other one a low level input right? Well, this is fine but when these two buttons are not pressed the inputs will be in an open circuit, I mean the      inputs will not be in high level or low level and this is not recommended. This is not a huge problem, it probably works with the Galileo but is a good practice keep the inputs define in a digital circuit as      high or low.

           

          For the 7 segment display:

               A 7 segment display is just an array of 7 LEDs with a common cathode (or anode) so these LEDs need a resistor, one resistor for each LED. Again, protect the LEDs with a resistor is a good practice      but your 7 segment display probably works fine. Another thing I noticed is that in your schematic there are only 6 pins connected, I think you forgot the last one, and also I don't see the pin for the      common anode (cathode), so check that in your schematic.

           

          For the servo:

               I think there is not problem with that, just try to connect the servo in a PWM pin. I'm not sure if it will works in a pin without PWM but you can try with both. You can check the Servo examples on the      IDE, I think this is the best way to start.

           

          These are my suggestions, let us know if were helpful for you. Have a nice great and enjoy your Galileo!

           

          Regards,

          Diego.

          1 of 1 people found this helpful
          • 2. Re: Working with Galileo (1st gen), servo motor, buttons and display
            eloher

            Thank you so much for your reply. Sorry for my late reply.

             

            I have improved your suggestions (with the exception of the servo, for now) into the project. This is the result:

             

            10634291_10204527092761439_2130534249_n.jpg

            What about now?

            Feel free to correct every imperfection!

            • 3. Re: Working with Galileo (1st gen), servo motor, buttons and display
              DiegoV_Intel

              Hi eloher,

               

              I see this new schematic looks good. The 7 segments display is now correctly connected but I think you are still missing to connect the common anode (cathode). Also, I will insist with the push buttons, I recommend you to connect them this way, check this link: push button schematic, it is not mandatory but it is a very good practice connect push buttons like this way. Just be careful because that schematic is for generate a high level input when the push button is pressed, so it will works for one of your push buttons without any change, but for the other one you have to modify this schematic to generate a low level input when the push button is pressed, not a high level input.

               

              For the rest, everything is fine so go ahead and enjoy playing with your servo and let us know if you have other questions. Have a great day!

               

              Regards,

              Diego.

              • 4. Re: Working with Galileo (1st gen), servo motor, buttons and display
                eloher

                Hi Diego, thanks another time for your reply, I have just now edited my project trying to follow your suggestions, can you give a look?

                 

                progettopark_bb.png

                Is it ok if I connect the push buttons with 3.3 volt slot? Or should I connect them to the 5 volt slot?

                 

                Thank you so much for your patience!

                • 5. Re: Working with Galileo (1st gen), servo motor, buttons and display
                  DiegoV_Intel

                  Hi eloher,

                   

                  Don't worry and ask everything you want. About the push buttons, you can connect them to the 3.3V slot or the 5V slot, both are fine. The difference is that in one way you will have a high level of 3.3V and in the other way you will have a high level of 5V. You can configure the Intel® Galileo Board to work with 3.3V or 5V. Check the IOREF jumper on your board to see what is the current configuration: 3.3V or 5V. I recommend you to use 5V, but if you prefer to use 3.3V is fine too.

                   

                  For the rest, I think all is good. Just one question, does your 7 segment display have common cathode or common anode?. This pin is usually connected to GND or VCC, not to other pin as I see in this schematic version so please check this detail.

                   

                  Let us know if you have more questions, feel free to ask and have a nice day!

                   

                  Regards,

                  Diego.