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Prairie Aurora Laser Launch

The Aurora laser launch from Prairie[1] is a solid-state laser system that can be used for fast acquisition using multiple LASER lines. It can be integrated with most microscopes using custom software such as Metamorph [2], using the electronic slider box that one can purchase from Prairie for ~2500 USD. Using it with Micro-Manager[3], however, proves to be way more economical and easier (~200 USD). In this article, we will discuss a step by step procedure for integrating the LASER launch with Micro-Manager, starting from hardware setup to "Micro-Manager"-hardware interfacing.


Before you Get started

There are a few things worth knowing about the integration before you get started. The Laser launch is designed to interface with other devices using a Gooch and Housego RF driver with DB-25 pin connector [4]. You should find out the pins that connect to individual laser lines and control them as shown in the pin diagram below. The DB-25 pin will not connect to a parallel port on your computer directly. Never attempt to do that. You will need an extended USB-interface board like the Velleman VM 140[5], which will interface with the AOTF and your computer. Thankfully, there is a Micro-Manager adapter available for the Velleman_K8061 that makes life easier for this integration. DB-25Pin Diagram.jpg


What will you need to get started

1. The Velleman VM 140 extended USB interface board and Female sockets (provided with VM 140)

2. DB25 Male IDC Crimp Connector

3. 25 Conductor Flat Ribbon Cable

4. Soldering station, Insulation tape


Hardware Integration

As you can see from the diagram of the DB-25 connector pin, there are three types of signals sent to the device through it. There is a TTL blanking signal, a positive input signal and a negative input signal. Three types of signals for each channel and one ground signal make this pin control up to 8 channels. The job of the TTL blanking signal is to turn a particular channel on or off. The positive input channel can control the voltage being sent to a channel (0-10 V).

Note
Here for the Prairie Aurora laser launch, we only need a maximum voltage of 5 volts

The negative input channel can serve as a Ground connector for a channel. However, you may also use the master Ground at pin #1 for grounding purposes Make sure that you understand the Analog and Digital outputs on the Velleman board before you proceed. For your reference, use the figure of the board below to attach cables correctly.


Velleman VM140 Board.jpg


The Velleman extended USB interface board has two types of outputs (See Figure above). The output male pins on the right are Analog outputs which will drive the TTL signals. There are digital output male pins on the left of the board. The first task at hand is to connect these pins to the correct pins on the DB-25 connector. It is best to use a 25 conductor ribbon wire and a DB25 Male IDC Crimp Connector for this job. Once you have the ribbon connector attached to the DB-25 male connector, tear out the individual wires depending on which channels on the AOTF, you want to connect. For instance, if you have two laser lines, one on channel 1 and the other on channel 2, you want to connect pins 12, 25 and 13 for running and controlling Channel 1 and 24, 11 and 23 for channel 2. Let us take these settings as an example and try to set the connections up. Here is a reference figure for understanding the connections between the ribbon cable and the Digital/ Analog Female pins.


Circuit Connection.jpg

Setting up the Analog Connections

Connect the female pins for the sockets on the Velleman board (they come with the board) on one of the analog sockets. Let’s say, you connect it on the first socket ( DA1-DA4 ). This will provide TTL inputs to the two channels. As mentioned earlier, the TTL input pins are 13 and 24. Solder two of the wires from the DA1-DA4 (its your choice, given how far apart you want the wires to be) with ribbon cable wire 1 and wire 4 respectively (See Figure). Also, for grounding, solder the blue wire (GND) with wire number 3 on the ribbon cable. Both the Analog connections and the ground for Channel 1 are set up now.


Setting up the Digital Connections

Connect the female pins for the sockets on the Velleman board (they come with the board) on one of the Digital output sockets. Let’s say, you connect it on the first socket from the top (05-08). This will provide digital inputs to the two channels. As mentioned earlier, the positive digital input pins are 25 and 11. Solder two of the wires from the 05-08 (it’s your choice, given how far apart you want the wires to be) with ribbon cable wire 2 and wire 5 respectively (See Figure). Also, for grounding, solder the blue wire (GND) with wire number 6 on the ribbon cable. The system is completely set up now as far as hardware connections go. Insulate the open soldered ends of wires with insulation tape.

Connecting the Board and Installing the Driver

Connect the USB cable between the Velleman board and your computer. Connect an unregulated 12 volts, AC-DC power supply (at least 0.3A) cable to the Velleman board. After you turn the switch on, you should see the LED with the RUN label start flashing. If you are using Windows, you will be asked for a driver. Most users make the mistake of using the Velleman driver (that comes with the board) at this point. You should select the option “Search for a driver to install” and enter the search path as: “Boot Drive (C):\Program Files\Micro-Manager-1.3\drivers. Windows will search and install the correct driver for Micro-Manager and Velleman interfacing now. [6]

Setting up the Hardware Configuration Wizard in Micro-Manager

If you already have a working configuration file, make a copy of it. When you open Micro-Manager, load your working configuration file (remember, we have a backup just in case things go wrong). Once everything loads, go to Hardware Configuration Wizard and modify the existing configuration. In Step 2 of 9, when you are to select ports the Velleman K8061 port should appear (along with any other port such as COM). Check it and move to the next step. In the next step (3 of 9) you will be asked to select devices. Select the K-8061 Hub. Now select K-8061-DAC. If you are using two channels, as in the case of this example, select another K-8061-DAC and give it a different name ( For the sake of simplicity, you may call these two DACs, K-8061-DAC-Laser Line1 and K-8061-DAC-Laser Line2.). In Step 4 of 9, you will be required to set up the pre-initialization settings for the selected devices. Click on the value boxes in the third column and set up the values as follows:


Device Property.jpg

After this step just go through the next steps as directed and finish the setup by testing and saving the file. Make sure that you save this file with a different name. Now you are all set to use your Prairie Aurora laser launch with Micro-Manager on your computer. A very good resource that you may also like to refer to for setting up the driver and the hardware configuration is Austin Blanco's blog[7].

Contributed by Saumya[[8]]


Last Edited by Saumya on 10-07-2010

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