RAREblog

C3Pi Teensy 3.0 and Motor Driver At the end of the previous post I let myself get a bit carried away! C3Pi has always used a Solarbotics motor driver. In the past it's been controlled by an Arduino Pro Mini. While the software for the Teensy is very similar, I needed to make a couple of changes to the code and more significant changes to the pinout. Slow and steady So my rush to solder up some stripbaord was premature. I've breadboarded the circuit instead. I've now got the Teesny 3.0 controlling it, and the Teensy is controlled by serial input. Since I've already checked that the Pi can drive the Teensy's serial port, I'm ready to go. Tomorrow's plan Tomorrow I will prepare the stripboard, connect the motors and take C3PI for his first outing. Initially I will control C3Pi via ssh over wifi. Come back tomorrow to find out how the project is going. If you want to meet C3Pi in person, come along to this Saturday's Southend Raspberry J...

The Pi and the Teensy are talking. The Teensy is running the fortune cookie sketch. I've been using pyserial on the Pi, and using interactive python. Here's a screenshot of an ssh session on the Pi: Next Step Next I'm going to solder up a mini-stripboard for the Teensy.

Teensy 3.0 Yesterday I started to set up the C3Pi's new brains - the Raspberry Pi model B+, with its lower power requirements, extra mounting holes and four USB ports. The USB ports are really useful; while I'm developing the new software, I need to connect a keyboards and mouse,  a wifi dongle and the Teensy 3.0 which will be used for motor control and other tasks. Teensies rule If you haven't come across the Teensies they are Arduino-compatible miniature boards developed by Paul Stoffregen . The early Teensies used ATmega chips, but the Teesny 3.0 and 3.1 use ARM processors. Paul has done an amazing job of extending the Arduino IDE and porting many of the libraries to work with the ARM chips. As a result the Teensy family are just as developer-friendly as the original Arduinos. The main attraction of the Teensy 3.0 is that it's faster, has more I/O, and much more RAM than the Arduino Pro. The fact that the Teensy runs at 3.3 volts is an added bonus, since i...

C3Pi B+ Pi, Quick2Wire board and downverter I'm busily working on C3Pi ready for his outing to the Raspberry Jam at Southend this Saturday. I'll be setting up my own mini-wifi network, but sometimes wifi doesn't work as it should. I need a way of configuring the Pi that doesn't rely on networking, just in case. When the Raspberry Pi model B+ first came out I built a  downverter - a cable which links the 40-pin header on the B+ to the old-style 26-way connectors. I linked it to a Quick2Wire interface board and plugged in an FTDI cable, which I connected to my laptop's serial port. Once I'd installed gkterm on the laptop I could log in to C3Pi using the serial console. So now I have a safety net! I don't think I'll need it, as I've also got the laptop, my phone and C3Pi chatting away happily on the private network, but it's good to know I've got options. I'm hoping to control C3Pi via a tablet or phone at the Jam, and for the ...

C3Pi+ C3Pi , the tracked robot that I've been working on for several years , just got a new brain: a Raspberry Pi model B+. The old version used a Model B with an Arduino micro. This one will probably use a Teensy 3.0 as the Pi's companion. (Less) Power to the Raspberry Pi The main reason for upgrading the Pi is the reduced power consumption, but the extra mounting holes also appealed. I took the opportunity of replacing C3Pi's old stripboard top with a proper pololu board, and the result looks much neater. I've added the motor controller which also provides a regulated 5v supply. My next job is to make a small circuit board to hold the Teensy and provide connection points to the Pi and the controller. C3Pi at Southend - Saturday 12 August C3Pi will be making an appearance at Southend this Saturday. The Southend Raspberry Pi Jammers are holding a big summer meeting, and C3Pi will be one of the many attractions. Book your tickets here !