From the hardware point of view, an ethoscope is rapsberry pi powered machine that tracks flies using a raspberry pi camera. In principle, all you need is a way to keep the camera at the focal distance from the flies and given that tracking needs to happen during night too so you will also need a way to keep infrared illumination. We normally print ethoscopes using a filament extruder 3D printer. We have three Ultimaker 2+ in the lab and we are happy with those. If you are not on a tight budget you may want to consider an Ultimaker 3 (amazon ~£7k) or you may want to go with an inexpensive model like the Creality 3D (amazon £250). I have no experience with cheaper models but my understanding is that the technology has improved a lot and I am pretty confident everything you will want to print can be printed on a Creality printer.
A typical 3D printed ethoscope in all its beauty
The node platform provides the most up-to-date list of files to be printed and I recommend you start from there. Click the "Resources" page and you will see a list like the one below:
If you do not have a node installed yet, you can access the very same links from this page too.
In this manual, I will provide instructions on how to build an ethoscope using the files versioned 1.7 and while I am confident update will roll out quickly enough, I do not expect them to change dramatically.
| Name | Vendor (link) | Cat No | Price per ethoscope (£) |
|---|---|---|---|
| Raspberry Pi 3 B+ | Farnell | 2842228 | 33 |
| Amazon | 60 | ||
| Raspberry Pi Camera PiNOir V2 | Farnell | 3677846 | 14 |
| Amazon | 29 | ||
| 32GB Class 10 MicroSDHC | Farnell | 3410189 | 7 |
| Amazon | 7 | ||
| 12V Infrared LED strip | LEDLightsWorld | HK-8MM-F5050-850-15-NW-IR-12 | 1 |
| Female 2x40 IDC socket (fits the GPIO) | RS Components | 625-7303 | 2.5 |
| Female 2x3 IDC socket | RS Components | 832-3613 | 1 |
| Male 2x3 IDC socket | RS Components | 832-3496 | 1 |
| 2 core DC cable | RS Components | 714-0313 | 0.01 |
| Tactile Switch | RS Components | 135-9601 | 0.05 |
| 60W USB Power supply | Amazon | ||
| Sticky tack | Amazon | 0.001 | |
| PI Heatsinks | Amazon | 1 | |
| 3mm opal acrylic sheet | sheetplastics.co.uk | 1 | |
| Amazon | 1 | ||
| Heatshrink tubing (1.6mm) | Farnell | 1008428 | |
| Heatshrinktubing (12mm) | Farnell | 4967239 | |
| Mirror reflective A4 paper | Amazon | ||
| 6-way Ribbon cable | RS Components | 693-7699 | 0.15 |
| Total | ~£65 |
You will not need any glue or screws to assemble the ethoscope because most parts will snap together. You will, however, need to make some soldiering on the wires. Some sticky tack is also useful to secure components and to darkened LEDs.
Insert the camera into the camera slot, fitting the four pins inside the four appropriate holes. Make sure the camera is well positioned then secure it down by pushing the camera cover lid. The lid will click into place making sure the camera will not move during experiments
Place the raspberry PI on top of the camera, positioned on its four pillars and secure the other end of the ribbon cable into the PI. It's easier to insert the PI into the case without the SD card in. You can then insert the SD card once the PI is fastened inside. Use some sticky tack on the PI pillars to secure the base in place, then close the lid of the case.