OpenLPM - The free, open-source LPM project!

[Trevor]

Well, Peregrine was in the works to be the solution - but for lack of someone willing to contribute from the Apple side, I might have to just write a Windows implementation.

Pending permission from Kenom, I can remove the handshake from Luminosity to make it compatible.

Or I can come up with a more lightweight version.

Trevor

 

[Trevor]

I've currently got a 2.0 release in a small beta test... major update.

Trevor

 

[Trevor]

OpenLPM Mk. I version 2.0 is ready for public beta!

https://dl.dropbox.com/u/6083542/OpenLPM/OpenLPM_Mk_I_2_1_1_5B.zip

• Added support for ALL current Arduino boards.
• Added support for an external ADC.
• Added support for a customizable curve adjustment.
• Added a feature that will, in the future, add support for third-party sensors such as the LaserBee sensors.
• Added automatic error checking at compile time, to help ensure OpenLPM will behave as expected.

Trevor

 

[Atomicrox]

This is pretty cool but it would be a hundred times more useful with a tutorial to make the sensor head.

If the tutorial had links to all parts (TEC, heatsink, coating paint) from Ebay/DX/whatever and a step-by-step coating guide it would take most of the guessing out of the equation. It'd still need calibration to be precise but I think it would at least be usable without calibration.

Keep up your great work

Edit: I'd be willing to code an open source grapher/logger for this if someone made a proper laser head tutorial!

 

[ARG]

This is pretty cool but it would be a hundred times more useful with a tutorial to make the sensor head.

If the tutorial had links to all parts (TEC, heatsink, coating paint) from Ebay/DX/whatever and a step-by-step coating guide it would take most of the guessing out of the equation. It'd still need calibration to be precise but I think it would at least be usable without calibration.

Keep up your great work

Edit: I'd be willing to code an open source grapher/logger for this if someone made a proper laser head tutorial!

This thread will show you how tot make the head: http://laserpointerforums.com/f42/diy-thermal-lpm-under-50-a-51129.html

Calibration is what makes an LPM an LPM. If they don't have that it's just a fancy voltmeter. Every coating is different, and not everyone has access to the same paints so the OPA gain will be different for everyone.

 

[Atomicrox]

Thanks for the link but that's why I mentioned links to internationally available online stores and a step by step coating guide. Calibration would be much closer and those of us that have no reasonable way to calibrate would have at least a rough estimate of power.

Another viable option would be a member willing to make, calibrate and sell the heads for a reasonable price. By reasonable I mean less than 100 bucks a head.]

 

[Trevor]

The issue of sensor calibration is something that we're (a few of the laserchat regulars - I'm not pretending I'm a company haha) working on.

I'm pretty busy with finals, but one of my projects over break is to work on finding a solution to this. Once we've got that, plus either a free or open-source datalogger, we're golden. Nearly free or at least cheap LPM's for everyone!

Trevor

 

[Atomicrox]

+rep for that!
I'll code the datalogger if you guys manage to solve the calibration issue. I'm way better with software than hardware

 

[ARG]

Yup, there is a foreseeable solution. I found a manufacture that sells TEC's pre-painted black. This way the paint would all be the same, and a gain could be found that gives a decent enough accuracy.
They require a large minimum order though, so I'll get a few samples then if all goes well we can do a GB for the TEC's or someone could stock them.

 

[Atomicrox]

I'm in, get the heatsinks as well to be sure everyone has the same.

 

[ARG]

Right, forgot about that detail. It would also be cheap enough to buy the OPA circuit parts in bulk and solder it all together as well, it's just the IC, a couple set resistors and a filtering cap. Easily possible to do all that for under 40$ (if the pre-painted TEC's are suitable for this). Heck, it would be easy enough to add a 14-bit ADC in there as well. Just add the 30$ Arduino and that's a full LPM with datalogging for under 80$.

 

[Atomicrox]

How about a $3 breadboard and a $10 Arduino Nano? That way everyone can change the layout/components if they want to. The 14-bit ADC would be absolutely great!

 

[Trevor]

How about a $3 breadboard and a $10 Arduino Nano? That way everyone can change the layout/components if they want to. The 14-bit ADC would be absolutely great!

The knockoff Arduinos have always... been unappealing to me haha. But it definitely a REALLY cheap option.

Regarding datalogging, I've already written Luminosity, its successor Luminosity 2.0 (which was licensed as Radiant Lightspeed), and started to work on Peregine. I think for the purposes of OpenLPM I think I'm going to try to get Peregrine finished. Peregrine's going to be open-source, so contribution is welcomed.

Trevor

 

[ARG]

Well, I think it's important to support the folks over at Arduino, but I guess it could be done with the knock offs to save costs. The quality of those looks... questionable.

It would definitely be easy enough to buy all the parts in through hole format for breadboarding, but the cheaper ADC's only come in SMD, so a SOT adapter would have to be made. I actually like this idea a lot more since it is in the spirit of Open LPM A modifiable open source LPM platform.

 

[benmwv]

I think it might be neater/easier to design a shield PCB since this is going to be used with arduinos. I wouldn't really want my LPM to be breadboarded since its kinda big, messy, and easy to break that way.

I can do a board layout if you want?

 

[ARG]

Already done that
I've made a few revisions. This is one with a character LCD. I'm making it for another member here, I thought it would make a fun project.

I have other boards with just the ADC and some other components for Ophir heads, and others with an OPA for TEC LPM's. They need further testing before I can release them open source.

(Please excuse my lack of ribbon cable, I need to rip apart more computers to replenish my stock )
The SMD revision is on the way for this one. I like to use through holes for first revisions, easier to trouble shoot.