Look Ma, No Wires!

Reliable high speed wireless connectivity between two or more Arduino boards is something that everyone wanting to get rid of a tabletop tangle of wires will eventually need to implement. As part of my ongoing ERP project, I have decided to modify the ERP chassis to carry a GPS and an array of ultrasonic rangefinders. By establishing a wireless datalink, I hope to be able to build an outdoor mapping robot that would be able to map its surroundings and transmit a 3D image back to a base station.

3d Mapping

3d Mapping by a robot. Image from http://rrt.fh-wels.at/sites/robocup/mapping.html

 

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Printer’s Hat : Much More Than Just a Hat

A Printer’s Hat is very easy to make. Even little children can learn how to fold it very quickly.

It is made from eco-friendly newspaper, fully biodegradable and has many many uses. It makes a super paper plate for chips and munchies at a picnic or at a campsite. Its great for holding soil for seedlings, lined with a plastic bag it can hold water, and painted or plain, it makes an attractive hat!

Here is my youtube video on how to make a Printer’s Hat!

 

Interfacing a USB GPS with an Arduino

Now that ERP1 is up and running, it needs to be able to fix its position and report this back over the wireless data link. I plan to develop a simple Kalman filter to estimate ERP’s position, but to do this, I need two things…..

(a) An Action Parameter. This will be in the form of a motion vector. Direction will come from a digital compass and Magnitude from a  wheel mounted optical encoder.

(b) Data Update. This will the estimated position of ERP1 obtained from an external fixing system such as the popular Global Positioning System (GPS).

GPS Constellation. Source : Wikipedia

GPS Constellation. Source : Wikipedia

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Experimental Robotic Platform Part 3: Wireless Commands and Remote Control

In this post I outline the progress made on ERP1 (Construction and basic electronics onboard ERP1 can be reviewed here) over the past few weeks…

ERP 1. Wireless Mobile Robot

ERP 1. Wireless Mobile Robot

The robotic arm is now fully operational. It has 6 Degrees of Freedom and can be controlled remotely from any laptop running the interface software.The robotic hand is capable of simple tasks such as lifting and carrying small objects. I have attached a wireless AV camera to the robotic hand. A human operator can now “see” what the robot is doing and issue commands accordingly over the wireless data link.

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Grab Every Hilltop

Let me see if I understand how Israel does what it does…..

1. Claim a historical/religious belonging to the land.

2. Buy up whole swaths of land from poor farmers. Settle there, reproduce, buy more land. Repeat.

3. If the locals rise up in opposition, massacre them. Assassinate the internationally recognised mediator trying to resolve the issue. Blow up a hotel while the going is good.

King David Hotel. Blown up by the IRgun in 1946 under the orders of Menachem Begin

King David Hotel. Blown up by the Irgun in 1946 under the orders of Menachem Begin. See 4 below.

4. It doesn’t matter that you ran a terrorist organization, you can still win a Nobel Peace Prize. Yes, thats right, a Nobel Peace Prize!!

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Experimental Robotic Platform : Part 2 – Electronics and Radio Communication

Once the Chassis for my Experimental Robotic Platform was complete, I got to work on the electronics and control sections of the robot. Here are some details about the electronics of my ERP:-

1. Power Supply.

Power Supply

Power Supply.

Power for the 4 high torque DC motors comes from a single 1.3Ah 12 V battery. The second battery (the taller one) is a 4.5 Ah 6V battery that will power the micro-controller unit (an Arduino Mega) and the six servos that control the robotic arm. Once basic testing operations are completed, I will add two more servos for a pan-tilt sensor mechanism (wireless camera/ sonar ranger/ IR sensor etc) that will also draw power from this 6V battery.

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Experimental Robotic Platform Part 1 – Building the Chassis

After successfully completing this superb online course from Stanford University on Machine Learning, I am now quite confident with designing and programming neural networks. Also, playing around with the incredibly powerful openCV library has got me experimenting with computer vision. If I were to try and put these two powerful tools together, and the most obvious outcome would be intelligent, vision capable robots.

But before I get into any of the complex programming needed to create these robots, I first need to build myself a proper ERP, an Experimental Robotic Platform. So this weekend, I spent most of my time working on an ERP chassis……….

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Robot Navigation with a Particle Filter

As robots become smarter, faster and more capable, they are being developed to perform increasingly complex tasks. In order to perform these tasks properly, robots are becoming more and more dependent on accurate navigation through the environment in which they operate. Somewhere in the future, if intelligent robots were to rise up and demand fundamental rights, I think one of the first things they would ask for is the answer to the question, “Where am I?”.

Where am I?

Where am I?

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A Bayesian Solution to the Monty Hall Problem

The Monty Hall problem was created by Steve Selvin and is a classic puzzle whose correct answer is counter-intuitive almost to the point of disbelief. As this page explains, even some of the most competent mathematicians of the 20th century refused to accept the correct answer to the Monty Hall problem for a long time.

Here is the statement of the problem :

Suppose you’re on a game show, and you’re given the choice of three doors: Behind one door is a car; behind the other two doors are goats. You pick a door, and the host, who knows what’s behind the doors, opens another door, revealing a goat. He then says to you, “Do you want to change your selection?” Is it to your advantage to switch your choice?

Monty Hall Problem. Image is from wikipedia

Monty Hall Problem. Image is from wikipedia

What does intuition tell us? After the host opens one door, revealing a goat, we are left with two closed doors, one hiding a car and the other a goat (50% chance of success either way), intuition would lead us to conclude that there is no difference in our chances of success if we switched doors or not.

If only life were that simple………….

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Removing Noise : The Versatile Complementary Filter

After playing around with DC electronics for almost a year now, I thought it was finally time to start mucking about in the world of Alternating Current. To begin, I decided to experiment with the ACS712 Current Sensor.

ACS712 Hall Effect Current Sensor

ACS712 Hall Effect Current Sensor

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