Dark Spot Mapper is a measurement system for imaging laser wafers and samples. It consists of a camera and a three-axis linear stage system.
Developed by Mika Mäki 2016-2020 for the Optoelectronics Research Centre of Tampere University and Vexlum Ltd.
As of 2020 the software is fully functional, but the user interface (dark_spot_mapper.py) is waiting for a major rework.
Supported libraries are National Instruments NI Vision / IMAQdx and OpenCV (USB webcams, FireWire etc.). OpenCV is recommended, as the National Instruments support is practically Windows-only and deprecated. FireWire support is not included in the OpenCV available from PyPI, and custom binaries have to be used instead. Docker-based build scripts for generating these binaries are provided in the repository. They have been confirmed to work on Linux, but on Windows they have not yet been properly tested.
Running the custom OpenCV builds may require the installation of various dependencies such as libhdf5-103 (included in hdf5-tools), libgoogle-glog0v5 and libtbb2. Depending on the build you're using, you may not need all of these. Python will inform you of the missing libraries when you attempt to start the software, so you should install the versions requested by Python.
Currently this software supports only Granite Devices SimpleMotion V1 linear stages. Supported platforms are Linux (x86_64, arm32, arm64) and Windows (x86, x86_64). The ARM Linux support is tailored for the Raspberry Pi. The included binaries have been generated using the Docker build scripts of this repository.
On Linux, if SimpleMotion cannot find the motor drivers (and FTDI driver cannot find the USB adapters),
check if there are USB serial device such as ttyUSB0 in /dev. If there are, it means that
the kernel libFTDI driver has taken over the devices and the D2XX driver included in SimpleMotion
cannot therefore talk to them. To resolve this, you'll have to copy the udev rule
99-simplemotion.rules to /etc/udev/rules.d
Then run
udevadm control --reload-rules && udevadm trigger
to apply the changes.
This rule also gives the proper permissions for the devices, but you may have to allow your user to use the serial
ports with the command
sudo adduser YOUR_USERNAME dialout
The udev rule may not be enough to keep libFTDI off the adapters, and you may have to disable the kernel modules with
sudo modprobe -r ftdi_sio and
sudo modprobe -r usbserial.
To make the disabling of the kernel modules permanent, edit the file
sudo nano /etc/modprobe.d/blacklist-ftdi.conf
and add the lines
blacklist ftdi_sio and
blacklist usbserial
Then run
sudo update-initramfs -u
to apply the changes after the next reboot.
If you have compiled the Linux binaries with Alpine and you run them on Ubuntu,
you have to install the package "musl-dev".
You will also have to manually create a symlink with
sudo ln -s /usr/lib/x86_64-linux-musl/libc.so /usr/lib/libc.musl-x86_64.so.1.
