Salvius robot preparing for balancing and gyroscope

This modification to Salvius's drive base is a prelude to a possible gyroscopic balencing system where the robot stays balanced on two adjacent wheels similar to the Segway PT invented by Dean Kamen. Although this will create a issue where if the robot runs of power it will simply fall over if it is not secured. One solution for that would be a pair of retractable stabilizers that could fold down and lock in place so that the robot could conserve power while remaining stationary for long periods of time.

One of the advantages of building the robot horizontally is that it can have more maneuverability in tight spaces as this new design greatly decreases the circumference of the robot's base. The reduced circumference also has contributed to a reduction of about 5 kg from the overall weight of the robot.

It is obvious at this point in the robot's construction that weight will be a major issue. At the moment, one large motor and the battery make up approximately 50% of the robot's mass. As a solution I plan on drilling out holes in many spots to remove as much material as possible without sacrificing structural integrity.

Turn on Computers using a Motion Sensor

In a previous post (http://salviusrobot.blogspot.com/2011/12/salvius-robot-motion-detector.html) an arduino microcontroller was used to close a relay to turn on a light when motion was detected. Now the same relay has been connected to the on switch of the robot's computer (a recycled PC) to turn the computer on, thus waking up the robot when someone walks into the robot's visual range.

Red and black wires connected to on switch.

Computer with keyboard removed to attach wires.

 In a previous post instructions were provided on how to remove parts on the laptop to modify its inner parts (http://salviusrobot.blogspot.com/2011/11/removing-lenovo-ideapad-s10e-lid-switch.html).

Lenovo Ideapad S10e on switch with red and black wire soldered on.

Salvius robot motion detector

Salvius can now "wake up" if someone walks into the room. This motion sensing feature allows the robot to conserve power by shutting down many of its primary systems and only turning on when someone is in the room with it. This is also a handy security feature considering that if the robot is on you can then connect to it if you have a web enabled device and see what it is seeing. The auto-activation system for Salvius uses an Arduino Uno, a seeeduino relay shield, and a PIR sensor. The code used in the video has been added at the bottom of this page.

Here is a quick demonstration of the new sensor works.

This is the code that was used in the video (above):

// Programmer: Gunther Cox
// http://salviusrobot.blogspot.com
// Created: 12/25/11
// Last Modified: 12/25/11
// Hardware setup instructions:
// Plug relay shield directly into arduino so that all pins line up.
// Attach 9 volt power supply to GND and +9V plugs of relay shield.
// PIR + to arduino 5V, PIR - to arduino GND, PIR OUT to HUB2 D3.

int relayPin1 = 4; // relay connected to digital pin 4 (D3 on relay shield)
int relayPin2 = 5; // relay connected to digital pin 5 (D2 on relay shield) (not used)
int relayPin3 = 6; // relay connected to digital pin 6 (D1 on relay shield) (not used)
int relayPin4 = 7; // relay connected to digital pin 7 (D0 on relay shield) (not used)
int pirPin = 2;  // choose the input pin (for PIR sensor)
int pirState = LOW; // we start, assuming no motion detected
int val;            // variable for reading the pin status
int pirMode = 0;    // determines if the relay closed already (0 = not closed yet)

void setup() {
  //the time we give the sensor to calibrate (10-60 secs according to the datasheet)
  pinMode(pirPin, INPUT);        // declare sensor as input
  pinMode(relayPin1, OUTPUT);    // declare relay as output
  digitalWrite(relayPin1, LOW);
  digitalWrite(pirPin, LOW);
  pirState = digitalRead(pirPin); // read the initial state
  delay(60000);                   // pause before calibrating
}

void loop() {
  val = digitalRead(pirPin);  // read input value and store it in val
  if(digitalRead(pirPin) == HIGH) {
    if (pirMode == 0) {
      if (val != pirState) {            //look for 2 inconsistant readings
          // turn main computer on
        digitalWrite(relayPin1, HIGH);  // sets relay1 on
        delay(1000);                    // waits for 1 second
        digitalWrite(relayPin1, LOW);   // sets relay1 off
        pirMode = pirMode + 1;   // relay has been on      
        //delay(50);
      }      
    }
  }
}

Setup for the PIR motion detector.

About the PIR sensor: