Tutorial: Adding Data Logging to the LB-A

I had this LPM sent to me by someone who wanted datalogging for their LaserBee-A. I thought I would do a tutorial for anyone else who wants to add data logging to their LaserBee-A.

To add datalogging I used the new v3 Open Source ARGraph. The entire part cost for this modification was only 25$
The new v3 datalogging is designed to be extremely simple to use, now you only have to connect two wires: Signal+ and Signal-
This datalogging board will work with many LPM's; the Radiant Alpha, No-Spin, LB-A, any Ophir 20C-A based LPM, and almost all DIY LPM's.

This tutorial is also posted on my website here.

Project Page here:
ARGraph
Sale Thread here: (v3 soon to be avaliable for purchase)
http://laserpointerforums.com/f39/fs-argraph-v2-lpm-data-logging-add-80227.html


Tutorial:

1. Buy (45$) or build (25$) an ARGraph v3 datalogging addon.



2. Disconnect the 9V battery from your LB-A

3. Remove the two phillips screws from the back of the meter (Circled in red). Put the screws some place safe where they won't get lost.



4. Locate the chip labeled "UA741CN" and solder a wire onto the 6th leg (Circled in blue) of the chip. This will be your positive connection. You may want to unscrew the PCB to solder the wire from the bottom of the PCB.


5. Locate the 2.5mm audio input and solder a wire on the leg closest to the case (Circled in red) This will be your negative connection.


6. (Optional step) Zip tie your wires together and twist the ends.

7. Cut holes in the case for the USB-B port and drill two holes for screws.
This can be done easily with a dremel, or a hand saw and drill. Cut it a bit smaller than you need and file the rest down for a perfect fit.
(Please don't forget to wear safety goggles!)


8. Add in the data logging board and use two screws to hold it in place.


9. Solder or connect the two wires to the pins on the side of the data logging addon. Make sure you get the polarity correct! The pins are labeled + and - on the board.


10. Screw the two halves of the LPM back together.


11. Download http://laserpointerforums.com/f70/peregrine-free-open-source-lpm-interface-80589.html#post1157733 and start datalogging!


Video of the data logging addon in action:

I hope this tutorial helps some people add data logging into their laser power meter! If you need any help please post here.

great write up!! laserbee owner rejoice, a inexpensive solution to your lack of data logging!!

Thanks This write up can also be adapted to the Radiant Alpha or the No-spin to add inexpensive data logging to them as well.

yeah this would also be a great add-on to the Blufan LPM!!

ARGLaser said:

I had this LPM sent to me by someone who wanted datalogging for their LaserBee-A. I thought I would do a tutorial for anyone else who wants to add data logging to their LaserBee A.

Click to expand...

Nice clean job cutting the enclosure....

Just 2 things...

1) I would not solder to the Pins of the IC as you show.
You can get the DPM's input signal by connecting a wire
to the pad of the Blue wire on the right side of our PCB
on J2.
There is also a free identified ground pin on the left side
of our PCB on J1.

2) Why is your graph so noisy. I know the output of our
LaserBee A is not that noisy and is quite noise free.:thinking:


Jerry

lasersbee said:

2) Why is your graph so noisy. I know the output of our
LaserBee A is not that noisy and is quite noise free.:thinking:


Jerry

Click to expand...

That's the image of Peregrine found in this thread: Peregrine

I wrote Arduino firmware that generates LPM "input" to use as a testing device when developing Peregrine. What you're looking at is the output of random number generation, not any LPM.

Trevor

lasersbee said:

Nice clean job cutting the enclosure....

Just 2 things...

1) I would not solder to the Pins of the IC as you show.
You can get the DPM's input signal by connecting a wire
to the pad of the Blue wire on the right side of our PCB
on J2.
There is also a free identified ground pin on the left side
of our PCB on J1.

2) Why is your graph so noisy. I know the output of our
LaserBee A is not that noisy and is quite noise free.:thinking:

Click to expand...

1. Yup, the positive connection can be soldered on there too, any point on the PCB that has continuity with pin 6 on the OP amp will work I chose to show the point so people can adapt this tutorial for use with other LPM's and other OP amps.
Thanks for pointing out the ground pin, I missed that. I'll be sure to use it in the future. The connections will work either way though, if people do a good job soldering then it will be all the same.

2. That's just the stock image from Peregrine, you can see what the actual output looks like in the demonstration video; it's a very clean reading.

right after i sell my A this comes out.......just kidding!
good work arg!
will this increase the range of the lb a above the 2W limit of the lcd?

cheech226 said:

right after i sell my A this comes out.......just kidding!
good work arg!
will this increase the range of the lb a above the 2W limit of the lcd?

Click to expand...

Thanks! :beer:

I would have to look into the hardware of the LB-A to make sure the OPA could go above 2V output, and to make sure the sensor wouldn't get damaged.

I'm pretty sure it's the exact same sensor on the 2.5W USB, so this could probably go up to 2.5W with the data logging. The non-linearity of the sensor may come into effect then though, so readings may be off a bit when reading above the rated spec.