Create your own magnetic optical density meter
We have created a magnetic optical density meter dedicated to the analysis of magneto-tactic bacteria, and invite you as a developer in an open source community.
- Up to 800 samples per second, allows precise analysis of the rotation speed of magnetic bacteria
- Three-dimensional quasi-Helmholtz configuration, with fields up to 3.5 mT and pulsed up to 13 mT.
- Three color LED: red: 645 nm, 1000 mcd, green: 520 nm, 1700 mcd and blue 460 nm, 500 mcd
- Power supply with current feedback to compensate for coil heating, cut-off frequency 200 Hz
- Split detector photodiode (sensitivity 0.5 mlx, with green LED theoretical max OD range of 5.8)
- Integrated pre-amplifier, SNR 83 dB (max OD range 4.0).
- Dedicated 16-bit ADS1115 DA converter
- Integrated temperature sensor
- Reference light detector
- Scattered light detector
- Fully programmable (ESP32 using Arduino IDE), open source
- User friendly spreadsheet recipe definition (csv format)
- Data collection on SD card
- Onboard Wifi link to access data
The sources we have available are:
- Measurement head design, 3D print file (OpenSCAD, on Thingiverse)
- Spice simulations, electronic diagrams, PCB layout (Spice, KiCad on Dropbox)
- Laser cut pattern for housing electronics (DXF, on Dropbox)
- Arduino program code (.ino, on Github)
- Matlab program to analyse datafiles, with GUI (on Github)
How to join