pine 140 Posted November 27, 2011 Share Posted November 27, 2011 Are there any recommendations for laser modules that work with the trick of shining to the LED on a LaunchPad? I found the security board from a forum member here really interesting and was trying to replicate with a simpler version. The original link is here viewtopic.php?f=9&t=1837 Several commonly available laser pointers were used and they all are good at the trick - the LED on the LP responded to the laser and can be used as trigger. However, when the module is disassembled from the laser pointer, they all seems to "magically" lost the power like in half and it not longer fit for the purpose. The best one lasted for like half day run with the original power, after that it is like half power. When it was good, 3V from the LP is supplied and it was as strong as the original. The original form (before disassembling) took 3 1.5V coin cells. I tried with a 5V supply and it is still dim Any help or suggestion will be much appreciated. I am also trying to source a proper one like the one from here: http://hk.element14.com/jsp/search/prod ... ku=1272658 Will it work by simply giving voltage and ground or is there a need for some kind of driver? Thanks in advance. Quote Link to post Share on other sites
bluehash 1,581 Posted November 27, 2011 Share Posted November 27, 2011 How about this one: http://www.sparkfun.com/products/594 Also in the pic... that looks like a LED, not a laser diode...or am not sure. I've always pictured laser diodes with a lens on top. pine 1 Quote Link to post Share on other sites
pine 140 Posted November 27, 2011 Author Share Posted November 27, 2011 Thank you bluehash That one in picture is a disassembled from a "dual purpose" laser pointer, one for LED and another one (in the gold color casing) is the laser part. Actually i had another "triple purpose" disassembled - LED+laser+UV light (for shining to note for the flourence markings) I've looked at the sparkfun one before and was very interested getting one, but unfortunately it's out of stock.. Quote Link to post Share on other sites
bluehash 1,581 Posted November 27, 2011 Share Posted November 27, 2011 Try this. But read the reviews first: http://www.dealextreme.com/p/red-laser- ... m-5mw-5914 pine 1 Quote Link to post Share on other sites
pine 140 Posted November 28, 2011 Author Share Posted November 28, 2011 Try this. But read the reviews first: http://www.dealextreme.com/p/red-laser- ... m-5mw-5914 Thank you bluehash! Definitely will try these.. look back i should have asked here first before killing those laser pointers Quote Link to post Share on other sites
websterling 12 Posted November 28, 2011 Share Posted November 28, 2011 AixiZ http://www.aixiz.com/store/index.php has a good selection of laser modules at reasonable prices. I ordered 5 modules and some assorted parts for a recent project and they worked fine. They did ship one wrong part but corrected it promptly and didn't want the wrong part returned. pine 1 Quote Link to post Share on other sites
username 198 Posted November 28, 2011 Share Posted November 28, 2011 Try this. But read the reviews first: http://www.dealextreme.com/p/red-laser- ... m-5mw-5914 This is what I used in my design. They work decently. 5mW is pretty much all you need. If you make some 100mW+ laser your probably going to end up burning out the LED or your eyes for that matter. *note, there pretty darn hard to break apart and mod the insides. Currently they have a cap on the line.... not sure how big. So your going to run into problems if you try to PWM it at a very high speed. pine 1 Quote Link to post Share on other sites
cde 334 Posted November 28, 2011 Share Posted November 28, 2011 Was the casing metalic or plastic? You might have overheated and killed it. Quote Link to post Share on other sites
username 198 Posted November 28, 2011 Share Posted November 28, 2011 Was the casing metalic or plastic? You might have overheated and killed it. not with a 5mw? provided your driving the laser correctly it shouldn't overheat at 5mW. I guess if in his modding he connected it directly to power he may have LED-ed the laser diode. Make sure you hook up your multimeter in series with the laser and ensure its not drawing more than 20mA. a 5mW laser generally shouldn't draw any more then that. Quote Link to post Share on other sites
pine 140 Posted November 28, 2011 Author Share Posted November 28, 2011 Try this. But read the reviews first: http://www.dealextreme.com/p/red-laser- ... m-5mw-5914 This is what I used in my design. They work decently. 5mW is pretty much all you need. If you make some 100mW+ laser your probably going to end up burning out the LED or your eyes for that matter. *note, there pretty darn hard to break apart and mod the insides. Currently they have a cap on the line.... not sure how big. So your going to run into problems if you try to PWM it at a very high speed. Thank you for the recommendation! I'll be sure to try that too. May I ask that the two wires are the only ones needed? I mean, if I am not ready to do PWM or something more sophisticated security than to simply shining the LED for triggering an on/off, can I just wire the red to a GPIO or Vcc pin and the black to ground, and the laser will go off? Quote Link to post Share on other sites
pine 140 Posted November 28, 2011 Author Share Posted November 28, 2011 Thank you all for your advice and teaching While souring the proper gear for this, I tried the last one I have with a modified design - if it doesn't like to be disassembled, then ok, I'll keep it as is: Used a metal ring with adjustable radius to secure the laser push button, and then wired the +ve and -ve respectively with some "hooked" wire (solder does not seem to stick). So far it is running fine.. maybe there are some anti-intrusion built into these little laser Quote Link to post Share on other sites
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