This repository contains EDA design files for very simple adapter circuit boards to connect UCLA Miniscope and their coax cables to other connectors and devices, primarily the Miniscope DAQ box and a motorized rotary joint from Doric Lenses which uses connectors from the Harwin M80 series.
The design files were created using EAGLE (but importing them with KiCAD may work as well). CAM data will be available shortly.
You can find a full list of all parts used in these designs and where to buy them in the Parts List.
The design sources are licensed under the CERN Open Hardware Licence Version 2 (Weakly Reciprocal).
Use the Coax-to-SMAEdge design files, usually the manufacturer will do panelization of the small
circuit boards fo you. The solder the cable to this adapter, ground to the center pad, signal to
the SMA inner pin.
You will need at least the SMA-to-HarwinM80 and Coax-to-HarwinM80 adapters for this application, they are
included in the SMA-Harwin-U.FL-Coax_MultiPanel-Scored panel with all adapter boards.
With the adapters, we were able to use a Doric Lenses assisted rotary joint for animal experiments as displayed in this schema:
It is very important to keep the connection of the rotary joint to the DAQ board as short as possible (we fixed the board with a clamp for mechanical support on top of the rotary-joint). Also, no additional connector must exist between the coax cable and the Harwin connector that goes straight into the rotary joint.
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Depending on which adapter boards you need, panels for them are available as CAM data to send to your manufacturer. All panels use scoring for separating the individual boards (defined in the
VcutGerber layer), so make sure your manufacturer offers scoring as an option - if not you will need to modify the design to use milling for separation instead. Our manufacturer of choice for these boards was multi-cb. We used Chemical gold (ENIG) as surface finish, which is usually only required for tiny boards or ones with dense SMD component assemblies, but in this case we wanted to make sure the contacts are as good as they could possibly be for high frequency signals (HAL would highly likely have worked as well, but we didn't take that chance). All panels in this repository have only two layers and should be made from 1.55mm FR4. -
When soldering the Amphenol straight SMA connector onto a SMA-to-HarwinM80 board with a female connector, so it can be used on top of a Doric Lenses commutator, you may want to add a spacer between the SMA conector an the board (we used a tiny 1mm circuit board piece, but anything will work). This is because even with the thick 1.55mm board, the legs of the SMA connector will stick out and collide with the commutator surface, preventing the Harwin connector from going in fully. The only real way to prevent this would have been to make the circuit board longer or to use an SMD SMA connector, but those solutions come with their own drawbacks (for future designs, a SMD connector variant may be worth a try though). That being said, even with the Harwin connector not tightly plugged in at the top, we still did get the Miniscope signal through without any issues.
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For soldering the coaxial wire to the Harwin interface board, you may have problems with the thicker coaxial wire. We are using a pretty thin version (see the Parts List) so getting the cable through the hole isn't an issue - but we haven't tested this with the thicker default wire. Using the U.FL connector variant should always work though, and may be even easier to solder and to replace in case of cable breaks.