In an effort to demonstrate a new django-quick-start package I’m making at work (similar in purpose to pinax, but with some SpaceX-specific packages), I decided to create an Arduino data logger that is viewable through Django. The data from a couple different sensors is first collected with an Arduino. A Python daemon polls the Arduino periodically and asks for new data. The daemon saves this data to the Django database.…
Author: Josh
Mecanumbot Integrated Lights Test
I’ve finally achieved end-to-end control of the Mecanumbot’s LEDs! The latest hurdle which prevented me from writing the LED code was a RAM limitation on the microcontroller side. The solution involved swapping over from an Arduino Duemilanove with 1KB of RAM to a Seeeduino Mega with 8KB of RAM. The increased RAM also opens the door for me to code up the Mecanumbot low-level telemetry including items like bus voltage and bus current.…
3D-Printed iPhone 5 Car Mount
We got a new MakerBot Replicator 2 at work this month. I had been meaning to print an iPhone 5 mounting adapter for my car, so I thought I’d try to print that using the new printer! The goal of the mount was to fit onto a car mount that I had bought for my iPhone 3GS back in the day. The suction cup and stand part of the mount…
Mecanumbot Power Board
After a second revision, I have completed the power board for the Mecanumbot. This board has the following features: automatically selects between two batteries and the wall chooses the wall if available, otherwise drains the batteries one at a time provides power voltage and current measuring via ATmega168 running the Arduino bootloader communicates to the primary vehicle Arduino over I2C provides regulated 5V power for the robot LEDs Downloads Eagle…
Fluval Edge 6gal Aquarium Log
Check out my new aquarium! The tank is a six gallon Fluval Edge. I currently have it stocked with one male red gold tuxedo guppy, two female guppies, and one red cherry shrimp (four were eaten as soon as I put them in the tank.) I also have a couple live plants including Java Fern, Anubias, and Moneywort. I’m going to try and add some moss soon which will hopefully…
BP Hobbies 25″ Flat Wing Foamie Build
Thanks to the Christmas break, I have finally had a chance to build the 25″ Extra flat wing foamie kit I bought from BP Hobbies almost a year ago. The electronics were purchased from Hobby King and include four 5.5g Turnigy servos, one Turnigy 1300KV motor, and one Hobby King 20A ESC. Control is provided via a six channel Hitec receiver and the plane is powered by a 1000mAh Turnigy…
Automatic Daily Fish Food Dispenser
Meet Bob, the goldfish (pictured below.) Bob is a pet at work, and we needed to keep him fed over the Thanksgiving break. I had an Arduino and a servo that were free, so I wanted to make something that would supply him with the right amount of food for the four days we would be gone. I came up with a little cylinder that I 3D-printed with a MakerBot…
Quick Manual Control Demo
This weekend I added a wireless Xbox controller to the list of devices I can use to control the Mecanumbot. Before now I’ve been able to use a standard RC transmitter, a computer keyboard, and a Wiimote. I again used the ROS framework to integrate the controller. Built into ROS is a joystick node to interface with the wireless USB dongle and I had already built a node to listen…
Legorov Teleoperating Robot
I built this little robot out of Lego this week (see picture.) The electronics include an Arduino, a Sparkfun xBee shield, and an Adafruit motor shield. On the other side of the xBee shield is a linux box running ROS. With ROS I can generated velocity messages from my keyboard or with a Wiimote. These messages get sent to the Arduino which translates the commands into individual motor speeds. I…
Wifi Bandwidth Experiment
I had been noticing pretty poor Wifi performance with my Mecanumbot, especially when I’m trying to visualize data with rviz remotely. After a couple weeks of dealing slow performance and tethering the robot with an Ethernet cord, I finally decided to kick my Netgear WNR2000 v2 router to the curb and look for something new. I ended up with the Linksys E4200 after a quick search for “best Wifi router.”…