Joey R2 Stencils

The stainless steel stencils manufactured by Hackvana arrived today. Parts will be ordered soon ready for getting at least one board manufactured and running in the coming week.

Some pictures of the stencil:

Joey R2 PCBs

The PCBs for the second revision of the Joey-M flight computer have arrived from Cambridge Circuit company. This revision carries some minor fixes from the first as well as the addition of the new CUSF logo to the rear silkscreen.

Thanks once again to Cambridge Circuit Company for these fantastic boards.

Joey-M Hardware Complete

The Joey-M flight computer was soldered up this week, all going fairly well apart from some minor rework required on some of the finer pitched components.


Joey-M uses the uBlox NEO-6Q GPS with a Sarantel SL1202 passive antenna, along with a small I2C EEPROM such that configuration can be retained when Joey is powered off. USB is broken out to a Micro USB connector such that configuration and debugging can be achieved via the excellent u-Center software from uBlox, and the configuration saved to EEPROM.

Joey-M GPS

Joey-M uses the Micrel MICRF112 434MHz ISM band 10mW FSK transmitter with a twin varactor diode crystal pulling arrangement. Its 13.56MHz crystal has an 18pF capacitor on one side, and the varactor arrangement designed such that under no bias voltage, it also rests at 18pF.

One varactor has a large range of capacitance that allows the center radio frequency to be moved around by about 30kHz. The other varactor has a much smaller range, such that it can be used for very small shifts for FSK. Voltage is applied to the varactors by a twin 16 bit DAC from Linear Technology.

The radio stage of Joey-M is shown below:
Joey-M Radio

To ensure a clean spectrum and thereby increasing the ability to decode, the modulator input waveform is digitally filtered in a Gaussian shape to provide GFSK. The step response of the order-50 Gaussian filter is stored in EEPROM on the AVR, and is written out to the DAC on each change of modulator input voltage. A trace of the modulator input at 300 baud is shown below:
GFSK from Joey-M

A working firmware is currently running on Joey-M in preparation for a first flight this week. Later, temperature compensation for crystal frequency drift and more complex radio modes (MFSK) will be explored using the Joey-M platform.

Finally, thanks again to Cambridge Circuit Company for manufacturing these boards for us.

Joey-M PCBs Arrived

We got the PCBs for the Joey-M flight computer! These are experimental flight computers using the Micrel crystal pulling radio (see an earlier blog post), along with an Atmel AVR and a uBlox NEO-6Q GPS.

Thanks very much to Cambridge Circuit Company for manufacturing these PCBs for us!


New Website

After a long time working on it, we launched our new website yesterday. We hope the change makes the site more user friendly and easy to navigate. We’ll be adding more content over the next few weeks.

Thanks to everyone on the CU Spaceflight team who was involved with the new site, we think it has been worth it!

Cambridge University Spaceflight


From the edge of space a tiny camera captures the dramatic curvature of the Earth, during a test flight that is one small step for Cambridge University students aiming to launch a rocket into space for under £1,000. – The Guardian

Cambridge University Spaceflight is a student run society founded in 2006 comprising undergraduates and postgraduates from many disciplines. We design, build and test high altitude balloons, high powered rockets, and other related experiments. Our main aims are to inspire and provide practical experience to Cambridge University students.

Team Meeting

We have some new members working on new Arduino trackers, following in the footsteps of the very successful Weasel project last year.

In the vein of ramping up work on rockets this year, some have been ordered! We’re getting a LOC Precision ISIS, a LOC Precision Caliber ISP and a LOC Precision Bruiser EXP. Hopefully the ISIS will arrive in time to get playing as soon as possible, while the Bruiser should be big enough to start testing a lot of electronics.

The Weasel Arduino Tracker launched on Nova 19

The Weasel Arduino Tracker launched on Nova 19

UKHAS Conference

Several CU Spaceflight members attended the first annual UKHAS conference in Islington, London this weekend.

Jon and Adam gave a talk introducing the society and the new Wombat radios and flight computers which are currently in development.

This was followed by Ed’s talk on the Squirrel smartphone flight computer project.


Nova 19 Recovered

After four months in a tree in Exning, the Nova 19 payloads (Squirrel and Weasel) have been recovered thanks to the help of some local tree surgeons.

The Weasel payload with its Canon A560 camera took some stunning photographs.

Nova 19 Horizon

The view from Nova 19, miles above the clouds.

See all of the Nova 19 images on Flickr.

The Squirrel Nexus One smartphone was also extremely successful, taking some excellent images and videos.

The Android Nexus One smartphone from project Squirrel

A shot from the Android Nexus One smartphone from project Squirrel