RAREblog

C3Pi from above I went along this morning to the Elephant and Castle Mini Maker Faire to introduce C3Pi to some of my fellow makers. The event was extremely well organised and I had no problem finding my desk and setting up. Before long C3Pi was running through his paces - fairly limited at the moment, as he still has no sensors and is controlled by a very simple command line interface. That's about to change, thanks to Joe Walnes' brilliant websocketd - more details below. In spite of his limited repertoire C3Pi soon made new friends and performed admirably. It's always a little nerve-wracking when he runs on a desktop. He has been known to get over-excited and career off in unexpected directions, but this morning he behaved himself... Power problems ... until just before lunchtime, that is. I'm still not certain what happened, but I think C3Pi's batteries ran low. What I know is that the ssh session connecting my laptop to the Pi suddenly starte...

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 !

and a worry! Farnell element14 have just delivered my new Raspberry Pi Model B+, along with some 40-way connectors. The Pi is destined for C3Pi , my Pi+ Arduino tracked robot. The main benefits of the Raspberry Pi B+ for C3Pi are the extra USB sockets and the reduced power consumption. I can see all sorts of possibilities created by the 40-way extended GPIO header, but I don't expect to take advantage of those in C3Pi. Unboxing the Raspberry Pi model B+ Raspberry Pi Model B+ Here is the Pi model B+. It's familiar, yet subtly different from its predecessors. It has a neater look about it and the 2x20 rows of GPIO pins are clearly ready for some serious work. I have one big question, which I hope to answer shortly: what is the hardware revision of the new board? Will some Python libraries crash on the Model B+? The board revision matters more than you might think. Back in the days when I was running Quick2Wire I came up with a little Python script you cou...

At last C3Pi can see , thanks to the wonderful Raspberry Pi camera module. You're squinting, C3Pi His first attempt at photography isn't going to win any prizes for composition, but no doubt he will get better with practice. I need to add a robust holder for the camera, but it should mean that we can take some photos at the Kids Adore Ditch event on Thursday. If we're really lucky we may even have streaming video.