How do I wire this circuit and program my controller?

Discussion in 'The Projects Forum' started by levi.dawson94, Jun 12, 2017.

  1. levi.dawson94

    Thread Starter New Member

    Jun 12, 2017
    I personally have limited knowledge and experience in the field of electronics, due to this, I would appreciate help in figuring out how to create and implement this circuit. To help understand a rough idea of what I'm aiming for I have attached a couple drawings. Also, I have no idea as to how to program the servo controller to work based on the goals, although I do have the arduino software, I'm just unsure what to do exactly.

    Aim: The aim of the project is to be able to move the load around the fixed point/bearing using the servos. Due to the weight of the load, there will be a servo on each side and the "rotator" from the servos will connect to the bearings with a cog system to rotate the bearing. Because the servos are on opposite sides they will rotate different directions.

    Idea: Now the idea is that when the back sensor has pressure applied, the servos will move the load towards the sensor, as shown in the mechanism drawing. To do so, the left bearing will have to rotate outwards/ to the left, and the right will have to rotate outwards/to the right, at the same time. The angle I'm aiming for is approximately 60 degrees of rotation for the load. Then once the front sensor has pressure applied, the load will revert back to its initial position, so the servos will rotate in the opposite direction, again back to the initial position.

    Also, I have a couple other questions which I'm unsure about.
    Battery: For the battery, I would like to use Samsung Galaxy batteries, due to their compactness and high charge. However, in order to achieve a higher voltage, I will need to connect 2 in series, which will bring the total voltage to 7.7V.
    Controller: I currently have the Pololu Micro Maestro 6-Channel USB, which has a voltage range of 5-16V, so theres no issue with the battery supply overloading the controller, however, it says it makes a regulated 5V available to the user. Now I'm not sure if that regulated 5V is throughout the controller or what is supplied outwards from that to other components. If it is supplied to other components, such as the servos, will that decrease the performance of a 6V servo or even make it redundant? And if so, would there be a way to bypass the supply from the controller and still use it to communicate with the servos?
    Sensor: The sensors I'm hoping to use are force sensors which decrease the resistance when pressure is applied. So due to the force applied being a desirable several dozen to maybe 100g to activate the servos, would there be a specifc sensor required which is highly sensitive? Or would a standard several dozen to 10kg sensor be sufficient with the assumed voltage supply, to be able to send the signal?
    If any more information is required just let me know and I'll do my best to supply it.
    Regards, Levi.
  2. blocco a spirale

    AAC Fanatic!

    Jun 18, 2008
    You've got quite a lot to do there. I think the best place to start is to put the electrical and mechanical details aside for a moment and concentrate on the basics. Essentially you have a micro-controller that takes input from a sensor, does some processing, and then outputs a value to a servo.

    I would start by learning how to program the micro-controller to read a value from the sensor (or a potentiometer may be more convenient) and output it to the serial port. Then write the servo control routine and control the position according to the incoming analogue value from the sensor.

    The important thing is to be methodical and tackle one thing at a time.
    Last edited: Jun 13, 2017