If you have ever dreamed of building a suitable spectrometer, it seems that the ESPROS epc901 CCD sensor is absolutely worth your attention. It’s fast, responsive, easy to interface, and at just US $ 24, it won’t break the bank. There’s just one problem: Implementing it in your project means either working with the 2 × 16 BGA device at 0.5mm pitch, or spending almost US $ 1,400 for the development kit.
Fortunately, [Adrian Studer] found a compromise. Although you still need to refound the BGA to mount it, its open the breakout and adapter boards for the ESPROS epc901 make the sensor much easier to use.
This is not only a hardware solution, it also provides the firmware code for the STM32L4 based Nucleo development board and some Python scripts which make it easy to extract data from the sensor. The firmware even includes a simple command line interface to control what hardware you can access via serial.
With the successful sensor, [Adrian] in partnership with [Frank Milburn] at build an affordable spectrometer around it. The design uses a 3D printed chamber, a simple commercial diffraction grating, and an array of inlet slits ranging from 0.5 to 0.0254 millimeters in width that have been laser cut from a sheet of stainless steel.
In the videos after the break, you can see the finished spectrometer used to determine the wavelength of the LEDs, as well as a demonstration of how the high speed camera module is able to study the spectral variations of a CFL bulb over time. [Adrian] tells us that he and [Frank] are open to suggestions as to what they should point to their new spectrometer, so let them know in the comments if you have any interesting ideas.
We have seen an incredible number of spectrometer constructions over the years, and some of the newer ones really push the limits in terms of what the DIY scientist is able to do in the home lab. Although they are still quite niche, these instruments are slowly but surely finding their way into the hands of more curious hackers.