Here’s a short little post to show something I made a few years ago. It’s a simple, tiny board with a couple of resistors that is used to measure the input voltage. It uses a simple voltage divider to reduce the voltage from the raw input pin and allow the conveniently close analog pin to read it.
This is the final post about the rover, I promise. In addition to the changes made to the electronics box, we also needed to get data from the wheels. Each wheel is a self contained unit with a battery, motor, and speed controller, which is sent pwm signals from the mbed. We needed to get the power draw from each wheel and this is the board I designed to do it.
In another episode of clearing up old projects, here’s a controller I made for the rover that acts as an emergency override and also allows somebody nearby to drive it around. The rover is typically controlled over the internet but there are times you may want to be able to control it without the internet, including when the internet connection is down. Any signal from the controller also overrides the signal from the internet user so it can be used as an E-stop.
Last summer I started working with the rover team to modify the rover to be used for another research project. The original rover did extremely well at the competition but they were working under tight time restrictions and almost all of the work was done by undergrads. That meant there was a lot of work needed to fix and modify it.
My Master’s research involved sensing the environment using a UAV or “drone”. Do do this I needed some method of reading sensors, logging data, and transmitting it back to the ground station. This post shows the three different designs I used and talks about them a bit. I’m not expecting this to be a super popular post but just want to document it so I can get it out of my brain.
I’m working on a robot project and one of the intended uses is to teach line following to college students. For this, I’m making an array of 9 RPR-220 reflectance sensors. This post will describe the part I’ve designed and the reasoning behind it. It’s a bit rambly so consider yourself forewarned.
Several months ago I wrote a post about a breakout board for the TB6612 motor driver. You can find that here. The reason I made my own breakout board for this was that the ones available from Sparkfun, Adafruit, and Digikey didn’t have diodes on the board. The TB6612 says it has internal diodes but those are small and I saw somebody online suggest always using external diodes. Today I realized I wasn’t sure if I actually needed them or not so I decided to do my own test to find out.
Part of a robot controller I’m currently working on involves using some motor controllers. Since this robot controller is expensive and I’ve never worked with h-bridges (other than in professional products) I decided to make a breakout board to test it rather than risk making a stupid mistake on the robot controller. Luckily, it all worked perfectly so I’m sharing it with the world so that other people can learn from it. Continue reading “TB6612FNG Motor Driver Breakout Board”
One of the projects I’m working on is a robot that has reflectance sensors around its circumference. I had trouble finding sensors that would work in the 0.25-0.75 inch range but eventually found the RPR-220. To mount this sensor, I made a breakout board with space for resisters and connections for positive, negative, and signal. Continue reading “Using the RPR-220 and a Breakout Board”
I’ve been using I2C a lot lately and something that keeps popping up is the need to send large numbers. I2C normally only sends a single byte at a time so you are limited to 255 as the largest number. This post will show you how I break large numbers apart to send them over I2C and reassemble them on the other side.