DiyLightAnimation
Hardware => Lynx USB DMX Dongle => Topic started by: kenlmcse on May 12, 2011,
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I built my dongle but it does not work. I have a steady red light and no green light. Windows finds the dongle and assigns it a com port. I did some testing using the specs from the data sheets. I have confirmed all my solder joints with a magnifying glass. I ended up using a compatible 22uf 16v cap, however I confirmed I get 5v out of both sides of the dc to dc convertor. I cannot figure out how to test the mosfit. I do not have power at the center lug, the datasheet does not help... I found when testing the power at the optocoupler that when I short pins 5 & 6 the green light comes on but dim.
Any ideas on what to do or where to go next?
Thanks
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Did you load the firmware on the Pic and confirm that it loaded properly>
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I forgot to mention that. Yes, I tested the pic and verified the pic was programmed.
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Unless I am totally wrong.
The green led will only light up when the dongle is sending out data. So if the dongle is connected to your computer and your run a sequence from your choice of software and or use something like RJ's dmx deck to send data. You don't need to connect anything to the output for this to work.
Red led is showing the dongle is getting power and Green led is sending data.
Cheers
Rick R.
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Do you have the FTDI drivers installed, by the sound of your first post, it seems like you let Windows install a driver. The Dongle needs the FTDI driver to work, if I remember correctly, also see this post
http://diylightanimation.com/index.php?topic=2805.0
RJ's reply is what I am referring to,
Bill
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Make sure that the Pic and the 485 are installed correctly and have no bent pins. Also make sure that the green LED is not backwards. You may want to post a few pictures of it so that we can see it.
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Like rick said, try using it was sequencing software and send some DMX information, then the green light should blink. I thought mine wasn't working either, but once I started sending information to the dongle (didn't hook it up to anything else) ... the green light started blinking.
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I recently had a port go out on my usb hub - no green light either. Once I switched ports all was fine. You could also build the handy little test circuit mentioned in this post
http://diylightanimation.com/index.php?topic=4890.msg81560#msg81560
a couple of leds and should tell you if the sig is good!
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There is a thread on here about a related problem ... related to the power saving feature in windows ... which turns off your USB port after a certain amount of time. And that forces you to re-plug it in before it will work again. I believe the symptom is the right light going off after a while. The fix is to change the power saving settings to disable the USB power-off, which is on by default, at least in Windows 7. Again, they is probably not your problem, since your getting the red light and just not the green. Send some signals to the dongle from sequencing software and see if your green light blinks.
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I have offically given up on this dongle. I am going to order new parts from mouser and try making another.
Tonight I reprogrammed the pic chip; tried a second pic chip I had. The other night I hit al the solder joints, I have taken voltage readings, ohm readings. All to no avail.
Maybe after I build a second (and it works) I will be able to figure out what is wrong with this one. At least my Open dmx dongle works
Thanks for all your input!
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You could post close up pic's, we could take a look, maybe find something that didn't catch your eye.
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When did you buy the parts? Last year there was some of the USB modules bad. Maybe you got one of those?
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There is no reason to give up, post pictures of it so we can look for issues. Answer the post that have info already here so we know where to move forward with. One person asked are you sending data to it. Another asked about how you loaded the drivers. They are waiting to hear answers before we can close out the common issues and give you the next step.
We will help you get it going.
RJ
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I am not giving up, I was going to order a new set of parts to build another. I bought two pcb's.
I order the parts last week from Mouser. My computer recongnizes the unit, Vixen regonizes the unit and xLights also recognizes it. I have tried sequences and Vixen/xLights testors. I totally removed the drivers with the removal tool and then reinstalled them. I erased the chip and reprogramed. I also verfied the chip as well. I will take pics of the board.
Thanks everyone for all of your help!
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could you have a bad led will the dongle send out dmx to a LE
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it is more than the led, it is not sending a data stream during a sequence. Correct me if I am wrong, the leds are simply indicators of what is happening, red means powered up, green means data flow.
I took multiple pics, here are the ones that are the least blury. I tried to get the solders at multiple angles. The solder joints that look like they have extra solder are the ones i hit again after looking through a magnifying glass.
Thanks everyone!
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How hot do you have your iron set to. It looks like it may be a little to cool.
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Same as I always do, But my tip is looking bad. Anyway about 3/4 of the way.
Here is my unit
http://www.amazon.com/Stahl-Tools-Variable-Temperature-Soldering/dp/B0029N70WM/ref=sr_1_6?ie=UTF8&qid=1305480476&sr=8-6
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I've circled what looks like a solder bridge in the attached picture, maybe something to look at,
Bill
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I've circled what looks like a solder bridge in the attached picture, maybe something to look at,
Bill
Extra solder from when I re-hit all the joints to ensure I soldered right. I left my soldering iron on so the tip got dirty. I should have cleaned it before checking all the joints. I paid the price by having extra solder on some of the joints. I cleaned up the excess.....
I really do think I either have a bad capacitor or the mosfit transistor is bad. One of the capacitors reads 5+ and 5- on both sides, the other one does not show the 5-. It is the one that comes out of the mosfit transistor.
If someone wants to read the voltage on both sides of their capacitors and let me know if the read 5v across it and if they read voltage from their mosfit. The outside framework is 5+, one of the outer lugs is also 5+, the other outer is 5-. the center lug should be the gate, it should read 5+, I am not getting that. But I could be wrong on my understanding of how a mosfit works.
My guess is I burned something out when I re-hit the joints with a dirty soldering iron. I think I had an original problem of a cold solder joint that I made worse with too much heat.
By the way, I replaced all three chips which is why I am now going down this road.
Thanks everyone!
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I'm not quite clear on what you mean by 5-. Measure voltages with the black probe of your meter to ground and use the red probe for measurements. In the dongle, there are two grounds; the PC side which is used for everything up to the input of the DC/DC converter (a good place to probe this is the top lead of the 4.7K resistor between the USB module and the oscillator) and the isolated ground after the converter (a good place to find this is the top end of the 0.1uF capacitor next to the 6N137)
If the MOSFET is off or not working, I would not expect to see 5V after it (or on the output of the DC/DC converter module). That certainly would cause the lack of output data and the green light being off. Note that this is a P-channel FET; pulling the gate to ground will turn it on.
There are a number of leads on the backside that look a bit long; component leads should be clipped a little closer to the board. I agree with Tbone321; it looks like your soldering iron wasn't hot enough, especially for the pins of the USB module. Pin 28 of the PIC also looks like it needs some touching up.
/mike
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Thanks you just gave me something that I cannot wait to get home from work to test. I was using the grn post of the usb module as ground and using the top of the mosfit for positive. I will try testing with the resitor.
Also, I cannot wait to ground it out to see what happens.
Thanks!