5/14/2006

Yeah!! Inexpensive Lab Gear!

Yeah!! I've finally found someplace that I can purchase inexpensive lab gear. In a previous post, I was talking about the specs and the possibility of designing my own scopes and meters. Designing equipment for myself would be very challenging and interesting projects but I would face the chicken-and-egg scenario such that I would need access to instruments to do various tests, but I would need to build them first.

So today, I finally found out where I can purchase inexpensive lab equipment. The two most expensive and important pieces of lab equiment is the oscilloscope, which allows me to measure various waveforms (sine waves, squares, saw-tooth et al.) and a waveform generator. At the moment, I have to first pay off some bills before I consider purchasing my own lab equipment but when I have the extra funds, I'll purchase the equipment.

5/11/2006

Hacking A RC Car: The Problem

It's been a very long time since I've played with anything that's radio controlled but with anything EE, I'll put my best foot forward and figure out how to "hack" a RC car so that it can be controlled on a computer. This involves interfacing the computer and the radio controller together. To do so, several issues would first have to be addressed.

1. Finding a microcontroller:
For those of you who are unfamiliar with microcontrollers, they are programmable devices that are used for dedicated hardware solutions. They are often used in data aquisition applications, control systems and anything else under sun since microcontroller applications are only limited to the designer's imagination.

In this particular scenario, I'll need a microcontroller that provides several functions, many of which are supported by almost all microcontrollers that can be purchased. To communicate between the computer and the microcontroller, I can use a USB-to-RS232 (USB-to-Serial) converter as long as the microcontroller's serial communications interface is UART (Universal Asynchronous Receive-Transmit). Time Input Capture and Timer Output Compare functions form timing applications such as reading and generating a signal. An 8-bit ADC (analog-to-digital converter) so I can interface various sensors to measure stuff like distance from an object. And if the microcontroller can store software to itself so that I need very little interfacing hardware such as noise cancellation capacitors.

2. Interfacing the radio controller to the microcontroller:
Since I'll be using an existing RF "architecture" the amount of interfacing work that I need to do may be no more than using the microcontroller to generate the required voltage levels to send the radio controller.

3. A PC User Interface:
Without going into a lot of work to create a graphical user interface, I would only need to create a bit of software that can send ascii codes through my USB. The ascii codes would represent the the direction to direct the RC car towards but I would not have the ability to give it a dynamic range for speed. It is entirely possible to give the car a dynamic range for speed if I were to use the user interface to send a string to the microcontroller. So, if I were to use the WASD scheme for direction, I can use the number pad for speed control where 1 is stop and 9 is burning rubber (or however the car moves).

So, after addressing these issues, hopefully an RC car has been hacked and we can control it from a computer.