At the Elephant and Castle Mini Maker Faire this weekend I picked up a £15 microscope kit from the guys at StoneTurners (hello!).
This is a hack kit based on a USB webcam where you remove the lens and reverse it to create a cheap microscope. In the box you get a set of parts including the camera itself, a plastic screw pot, some neoprene material and a few laser cut parts.
Instructions can be found over at StoneTurners along with some inspiring images taken with the scope. It’s an easy build – I did however skip over using the neoprene strips instead opting to hot-glue the webcam module inside the plastic screw-pot, and I had to bend the LEDs slightly to fit them inside the hole at the top. What you end up with is 2 ways to adjust the microscope – you can focus the reversed lens attached to the CCD module, and you can raise and lower the microscope ‘stage’ – being the outer part of the screw pot.
Here’s how mine ended up:
You can use the microscope with Camspinner on the Mac – this worked fine with no problems on my Yosemite iMac.
For the ultimate in budget scientific computing, you can use guvcview and plug the USB microscope directly into a Raspberry Pi. I used a model B+ and it worked fine just plugged directly into the USB port, although the low power warning icon did flash up a few times.
To install guvcview just open the terminal and type:
sudo apt-get install guvcview
then head over to the desktop with startx – the webcam software will be found under Sound and Video in the main start menu.
I did try installing Cheese, but that was a little bit too much for the Pi.
Finally, here are a few pictures I took just trying out the USB microscope:
an LCD screen:
and the tip of a ballpoint pen:
I haven’t tried anything living yet, but when it’s not dark and raining outside I’ll pop down to the thames and see if I can get a water sample. One interesting project might be to look at determining water quality based on what pond-life appears.
In conclusion it’s a fun kit for £15 and I look forward to seeing what they come up with next. You can buy the kit here.