Geoffrey L. Barrows's Blog (32)

We have updated the Stonyman data sheet to include software exemples (in Pseudocode). Version 1.0 is here: Stonyman_Hawksbill_ChipInstructions_Rev10_20130312.pdf

We have a small batch of ArduEye Aphids that are now available for serious beta users. An Aphid is essentially a clone of an Arduino Pro Mini but with a Stonyman vision chip and an external 12-bit 100ksps ADC added. For more details and for ordering, please visit the ArduEye Aphid product page…

Eager to make a little foray into the "Internet of Things", I decided to experiment with the use of an ArduEye as an "Eye for the IoT". My house is on a fairly busy street, of which I have a good vantage point from my attic home office. A car traffic counter seemed like a good choice for a first project.

I programmed an ArduEye Aphid to detect cars using a very…

This is the type of news that makes everything we do worthwhile! This past January, I was contacted by Alex Sayer, Alan Kwok, and Benny Chick, students at the British Columbia Institute of Technology (BCIT) in Vancouver, who wanted to use some of our Tam2 chips for a class project in which they would provide a human-computer interface (HCI) for people suffering from ALS (Lou Gehrig's disease) and could not operate a computer using their hands. Their idea: Use a low resolution image sensor,…

We've had a lot of inquiries about our ArduEye system, plus we've just prototyped a smaller, completely self-contained ArduEye (more on this in another post). So I figure it makes sense to discuss what is actually possible with one of these devices. True, the ATmega328 processing engine of an Arduino is limited compared to more advanced DSP, but the reality is that for many applications you really don't need a whole lot of pixels. If you can get by with specs of the '328 (16MHz as an…

I was pleased to see a cool laser rangefinding project on Kickstarter- I hope this project gets fully funded (and I'm a backer). I've actually been experimenting myself with structured light and laser rangefinding using our ArduEye hardware and thought I'd share it…

In a recent post we showed off a new ArduEye system using a Stonyman vision chip. A batch of 200 Stonyman breakout boards is (still) being fabricated. But in the mean time we decided to have some fun and prototype an ArduEye using an Arduino Pro Mini as…

Awhile ago we (Centeye) started ArduEye, a project to implement an open source programmable vision sensorbuilt around the Arduino platform. The first ArduEye version used a simple Tam image sensor chip and a plastic lens attached directly to the chip. After much…

I've been experimenting with using an Arduino-powered vision system to detect and locate point light sources in an environment. The hardware setup is an Arduino Duemilanove, a Centeye…

I've been working on a new version of our ArduEye using one of our "Stonyman" image sensor chips and decided to see if I can grab four dimensions of optical flow (X shift, Y shift, curl, and divergence) from a wide field of view. I wirebonded a Stonyman chip to a 1" square breakout board, and attached it to an Arduino Mega256 using a simple connecting…

This device is no match for an optical flow sensor made using an optical mouse, but it does (minimally) work. Think of this little project as a fun hack more than anything else.

This optical flow sensor uses CdS cells as light sensing…

As part of Centeye's participation in the NSF-funded Harvard University Robobee project, we are trying to see just how small we can make a vision system that can control a small flying vehicle. For the Robobee project our weight budget will be on the order of 25 milligrams.…

This is the third part of a three-part posting on chip design and how to reconcile it with the open source and DIY movements. (Part 1 is here and part 2 is…

Above: Concept for an "abstract layout" workflow that could reconcile open source circuit designs with "closed" process design rules and libraries. First the designer would generate an abstract layout by instancing cells for various components. The above example shows a 2-input AND gate, with one input pulled to ground with a 10k resistor, and a tri-state buffer as…

Above: Simple circuit using a transistor (an N-channel MOSFET), a resistor, and a capacitor. Left shows the schematic, right shows the layout.

Following discussions from a previous post in another forum, I’m writing a three-part blog post…

I just got back some new silicon! These are the latest image sensor chips I designed specifically for robotics and embedded vision applications. The pictures above show a full wafer followed by a close-up of the wafer from an angle. There are four chips in each…

I get this question a lot: Why is it that an optical mouse works fine on a desk, but when you lift it up and move it around it does not pick up anything. This question typically gets asked by experimenters trying to make a visual odometer using an optical mouse. A related question is about our smaller sensors- "How far can they see?" The answer is pretty simple to…

One important consideration when designing any vision system is the relationship between pixels in a camera system and angles and distances in the external world being imaged. This is important if, say, you want to know how many pixels wide an object would be at a certain distance, or how to convert an optical flow odometry measurement into a linear odometry…

I like Arduinos. They are inexpensive, open source, and insanely easy to program. The Arduino environment also comes with a nice little serial monitor making it easy to monitor what a program is doing and "debug" if necessary. So in the past we decided to hook up an Arduino Pro Mini to a FireflySmall sensor, to make an optical flow sensor. This worked, and we received a…

(Left: Arduino Duemilanove with Rox1 shield and Tam4 chip, Middle: Arduino Pro Mini with Rox1 shield and Tam4 chip, Right: U.S. Quarter for size comparison)

Well this might be a slight exaggeration- As neat as they are, an Arduino isn't exactly a supercomputer. But we did manage to use an Arduino to grab imagery and process optical…