Arduino and Cake

Arduino and Cake

This is a page of information for the (hopefully) regular 'Arduino and Cake' event we run at Makespace. This is an evening where we get together in the space to learn and hack on projects involving the Arduino and similar microcontrollers. As the name suggests, there's also cake!

Sessions

We've had one session, with all levels of experience from complete novices to expert embedded programmers. Everyone paired up, with beginners and experts working together; judging from the happy buzz of making noises (both the noise of making, and the making of noises - we had buzzers!) it worked pretty well. The meetup page for the first go is on meetup here

The plan is to have this as regularly as possible, varying the day around in case people can't make a particular day of the week. The second one will be next Thursday (the 8th of August); you can sign up here.

Helpful links

Arduino home page : www.arduino.cc
A bunch of useful little circuits to play with: Arduino Basic Connections

Projects

Got an interesting project or a project idea? Add it here.

Vehicle monitor / heating controller

I've re-wired my Land Rover, using a star topology, with a big central "ganglion" which almost all the wires run to and from. There's an extra wire coming from each connection, that will go to a board of LEDs and voltage dividers, the latter feeding into an Arduino Mega, which will monitor just about everything, and display information on a small LCD panel.

I'm also planning to make a motorized heater control system (moving flaps to direct air from an Eberspacher) and the valve motors will be driven from relays on the Arduino.

And there'll be a GPS/GSM security unit, and eventually a Linux board (probably Pandaboard) running navigation software. And later on, I hope, an electric motor to drive the extra axle I added. The Arduino Mega will route data between all these points, with its multiple hardware UARTS, as well as sending out information it converts locally from its own inputs.

I expect the software will be a main loop that polls all UARTs for incoming information, all wiring lines for changes from their previous state, all heating valve position sensors for whether they've reached the right position, all pedals for information to send to the traction motor controller when fitted, and does the associated actions (for example, NMEA sentences from the GPS get forwarded to the Linux board for navigation and are also used to display the time on the LCD, heating switches update the desired positions for flap valves).

JCGS 15:00, 2 August 2013 (BST)

Quadcopter

Because everyone loves autonomous flying robots surrounded by razor sharp rotating propellers, right?

A friend and I are working on a full self build of a quad rotor, we have the airframe, motors, props, speed controllers and an arduino with a combined gyro / accelerometer mounted. We just need to add batteries, wireless comms and software. I don't know whether I can persuade Si to come along to this meeting, he's not a member, but that's one of the things I'm playing with at the moment. I'm using the MPU6050 and PID libraries to manage the feedback between the accelerometer and the speed controllers in an attempt to get a stable hover mode, and the NRF24L01 as the radio module.

--tmo 15:12, 2 August 2013 (BST)

Bottle rocket telemetry

The family makers are making bottle rockets, I thought it'd be cool to try to make a telemetry module that would tell them how high they'd gone and render a 3d trace of the trajectory using either Processing or WebGL. The main challenge here is to get the circuitry small enough and tough enough to be carried by the rockets and then survive the return to ground level! The second issue is power, I have a LiPo battery and charger so should just be a case of a 3.3v regulator but maybe it needs a boost converter, not really my area of expertise so I'd really like some help there.

At the moment I'm interested in using an ATTiny85 (8 pin dip package MCU) as an Arduino, using the MPU6050 gyro / accelerometer and an XBee v2 radio - I'd use the NRF24 radio but I think it needs more pins than I have available on the ATTiny. Another option would be to use a rather more sophisticated Arduino pro mini, more pins means the NRF radio would be an option which is much cheaper than the XBee modules.

--tmo 15:12, 2 August 2013 (BST)

I2C plant moisture sensors

Program an ATTiny85 as an I2C slave, embedding it onto a circuit board etched to work as a capacitive moisture sensor. Use Arduino nano with ethernet shield as an I2C master to then monitor the moisture levels in my various outdoor plant pots and tweet when they're getting too dry.

--tmo 15:12, 2 August 2013 (BST)