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There have been 156 items by Magpie (Search limited from 14-May 23)
#32917 Powerful Aquarium Lighting
Posted by Magpie on 30 July 2012 - 11:17 PM in General Discussion
#32886 Powerful Aquarium Lighting
Posted by Magpie on 30 July 2012 - 01:07 AM in General Discussion
Seen plenty of similar errors myself.
the not connected, you just need to zoom in an check it is connected, I think the colour changes in the middle.
If you don't want to connect to a pin, you put a "NO Connect" symbol on blue cross. It's just a message to the DRC.
Also if you label a node, and want to use this node somewhere else you might have mistakenly give a different name.
There are also power markers, that you place like components, these may have the same name as labels but are different.
Eg. you have to label a node as GND if you want to use it in different places, but you also need to attach a power marker to it which will be called Gnd.
You have to say where the power is coming from, you can either ignore it or edit a connectors pin, if it is coming off board.ErrType(3): Pin connected to some others pins but no pin to drive it
@ (1.6750 ",1.2000 "): Pin 15 (power_in) of component IC1 is not driven (Net 10).
Ignoring it is fine if you are sure what is providing power. I did manage to get my design pass DRC but it was a bit of frigging around.
My mount holes are stupidly big on my board. I think my power vias could be bigger.
#32873 Powerful Aquarium Lighting
Posted by Magpie on 29 July 2012 - 01:50 PM in General Discussion
#32871 Powerful Aquarium Lighting
Posted by Magpie on 29 July 2012 - 12:39 PM in General Discussion
#32860 Powerful Aquarium Lighting
Posted by Magpie on 29 July 2012 - 12:09 AM in General Discussion
#32854 Powerful Aquarium Lighting
Posted by Magpie on 28 July 2012 - 02:41 PM in General Discussion
I have just been working on it now,
Sorry the cap was 3.9nF. No it is for the black regulator.Finally your last point was about 10K resistors and 39pf caps, I can see some 10Ks on the BOM but do I need to add the caps and if so will these do? CC1206JRNPO9BN390
I haven't fully tested the boards, only the black regulator.
I have just modified my original code to support the ADC differences, I am using differential inputs on the current sense, and one sided for the dimmers. You will put your TLC5940 square wave into the dimmer inputs, Share the grounds between the chips. the dimmer input must be 0-5v. PWM Square wave is fine, use a frequency just about 20khz or so.
For firmware I am using Amtel Studio 6 and an AVR Dragon, it seems to download ok, if I have any problems I will go back to version 4 which did work.
Last thing I need to do is rescale the current sense, which is just a constant.
Then turn it on and see what happens. I have been really busy but will try to get lights tomorrow.
Have you seen Mikes electric stuff he has a good video on small scale production, there is a link on hanzibals audio project that I posted.
They are quite good but I personally wouldn't use them as their DC resistance is a bit high at 334mOhms for 330uH. The smaller the package the higher the resistance.I have found some indutors on ebay that are really reasonable don't know what you think? SMT DS3316P
But that may be fine for you as super efficiency is not your main priority. The only way to reduce the resistance for the inductance is to go bigger.
You will have to weigh it up for your situation.
I just went with cheapie chinese phoenix connectors, for power and leds, but 0.1 inch pitch pcb pins for the dimmer and the ISP header. (both 2x3)I will also look at connectors as well at some point what did you go for in the end for power, LEDs and control signal?
497-5927-2-ND is wrong, use 497-5938-1-ND it is 5v operating voltage tvs.On the BOM I have made a few comments and corrections based on your advice I think I am almost ready to order now but just want to make sure I have got everything on there.
the little smd inductor is fine use that.
power inductor: see above it is ok but you might want to use bigger.
39pf dont use
the fet is still wrong, see previous post. If you are using 5 volts on the fet gate you need a logic level fet.
#32732 Powerful Aquarium Lighting
Posted by Magpie on 26 July 2012 - 11:40 PM in General Discussion
#32731 Powerful Aquarium Lighting
Posted by Magpie on 26 July 2012 - 10:46 PM in General Discussion
Hi,
I have it down to 5 mosfets, which do you think would be best for the job? I have tried to fit your suggestions above:
MTD3055VLCT-ND
MTD3055VLDKR-ND
497-4335-1-ND
497-4335-6-ND
IRLR014PBF-ND
Finally will these do for the inductors? 811-1222-ND or These?
Many thanks,
Andy
I have assembled the board, I had one big mistake, one of my Black regulator transistors was around the wrong way, And I also put the wrong package on for my mosfets.
Luckily they just squeeze in.
the Black regulator is working.
I need to write the firmware to test the actual dirvers, and especially the current sense part. I should be able to get some results this weekend. Things have been a bit hectic lately.
I'll look at the Fets now.
#32606 Powerful Aquarium Lighting
Posted by Magpie on 24 July 2012 - 10:32 AM in General Discussion
You can't use the FDB3502 at all! Not at 5v.
This is a N Channel normal level mosfet. I am driving this at about 11 volts on, 0 volts off.
You need an N Channel logic level mosfet. You will drive this at 5 volts on, and 0 volts off.
Get one in the same package size (DPak, D2Pak)
, with a roughly similar Gate Charge Qg ( 10-30nC) lower is better.
and a low RDS on. I marked it in yellow because it needed changing. Sorry for not making this clearer.
If you used the FDB3502s they would still work, but they wouldn't switch fully on so they would have a higher Rds.
The net result is they would run hot and waste energy.
I can't remember what you want the 1u for, it probably wont hurt. Is it C1? For decoupling the power input pins of the attiny. If it is I have used 1u ceramic.I added in the capacitor that was a 1u to my BOM
I don't follow your question. Sorry did I leave it out of the BOM I sent you? It definitely needs to be there.
Edit: Confused gate capacitance with Gate Charge
#32580 Powerful Aquarium Lighting
Posted by Magpie on 23 July 2012 - 11:44 PM in General Discussion
#32016 Powerful Aquarium Lighting
Posted by Magpie on 14 July 2012 - 01:03 PM in General Discussion
I made some changes, added to new column that flags the changes.Please can you confirm that I haven't made any mistakes?
I left the inductors at 100u you can probably go smaller as well, probably down to around 10u. So many variables to choose these. 100 will be fine if you have them but say 33u might be better, but only marginally.For the 5v version, you mentioned I need a smaller inductor, can you recommend any that would be good for the job? Or will either of the ones I all ready have do the trick which seem to be 100uh and 330uh?
Look for operating voltage of 5v, but since you are providing a regulated low noise supply off board, the only thing this will do is protect against reverse polarity.You also said I need a different TVS diode, what would you recommend for this? PS I am probably going to order from Mouser in the UK.
Also bear in mind that you need to provide the regulated low noise supply off board because this is what the 12->5v part of the supply was doing.
No the sense resistor is about right, it will be ridiculously efficient but may be prone to noise.I guess the current sense will change in value right? Do you have the equation for 700ma from a 5v input?
You may want to try 200mOhms. I tried to layout my board inputs as "kelvin" inputs. Unless you do this well your current sense inputs will be prone to noise.
Any prototypes you may want to use up to 500mOhms.
Calcs: 100mOhms at around 700mA the current sense should read .7 x .1 = 0.07 volts at full load.
We are not getting all that 700ma through the sense resistor so say we get 500mA. ( Some goes through the Shottky). = 0.05v
then we multiply by 32 in the internal gain stage = 1.6 volts. our full scale may be 3.3 volts so we get a reading of 500/1024 at full current.
Your pwm outputs should feed straight in to these as long as they are 5v full scale. Dont connect the 5v but connect the rest.Finally the parts for the dimmer channels, are these already on the BOM and do the values still stand for 5v?
Apparently they are in transit.Have you recieved your boards yet and got one soldered up?
I have the parts from Digikey. The murata inductors look a mess, they must've been made by the apprentice. The last ones looked great.
I have also got some really fine prismatic diffusing glass on order, it breaks up the leds nicely. The plastic ones are good too but they look shit when they are turned off.
Good luck
Attached Files
- Steff2 BOM revised for 5v.zip 4.88KB 1 downloads
#31702 Powerful Aquarium Lighting
Posted by Magpie on 07 July 2012 - 01:54 PM in General Discussion
Thanks for pointing out the missing caps from my BOM, it was also missing R1.
All the caps are just decoupling or filtering caps of 100n 0805 and the Resistor was just a 10k 1206.
I cant believe I made this mistake, It just goes to show how easy it is. I am definitely not a computer.
I haven't gone exhaustively through your list as it seems your not quite decided the best way to go anyway.
As far as boards go I would go the modular approach, so if a board fails you can have spares, x channels per board.
Maybe 3, maybe 8, maybe 16. Design decision.
Also that way you could have some boards at 12 volts some at 5.
Actually on the subject of design decisions, the way just about every project I have worked on has been is that you never design it right first time anyway.
So there is no point trying to perfect the initial design. The moment the first working version comes out, somebody sees things that they hadn't noticed before.
So I think,
- Get something out there,
- Get something out there that isn't impossible to change or fix.
- Keep changing it till you think it's right.
I am writing as I think so the conclusion of what I think you should do is 3 channel boards (wait till I confirm that the design works) start with 5 or 12 volts, (your decision) and see how things go.
As far as 5 or 12 volts for 1 led.
5 volts can be slightly more efficient but, will it always be one led, because you can't easily change it.
If you go 5 volts you may have a noisy supply to the micro, this may or may not be a problem for the Current sensing on the Attiny.
If you go 5 volts you don't need the step up bc847 and it's two resistors. But you do need a different, logic level FET, just like AHellene's circuit.
5v you can use a smaller inductor.
I would use 12 volts but there could be a case for 5v and event a case for 7 volts.
If you want to use my circuit with 12v
just use a different TVS (12v operating voltage).
and remove everything including C3 to L2 reading left to right on the schematic.
Jumper the 24 volt rail to the 12volt rail.
If you want to use my circuit with 5 volts.
just use a different TVS (5v operating voltage).
and remove everything including C3 to U1 reading left to right on the schematic.
Jumper the 24 volt rail to the 12volt and the 5 volt rail.
you don't need the 3 x step up bc847 and short r13 to r15 and open circuit r16 to r18
It gets a bit harder as you may need a clean supply for the micro. I don't know.
Personally I wouldn't bother. It probably would be ok, but I think 12v will give you what you need.
No the netduino can only source less than 1 amp.Do you think this side of the circuit can be powered practically off the netduino
I would power the netduino from my 12v supply. Maybe via a resistor to just take away a bit of the heat.
That is a mistake, it was left there from some other current sense resistor that I had considered, please disregard.Also one of the resistors is marked as a bit wide, is this the foot print or the value and does it matter?
ps. You probably don't want to populate r28,r29, r30, I just put the footprints in for emergencies. I think 100mOhms if the lowest we could go anyway.
Also you don't need R12, this is also a contingency footprint.
You will loose very little running 1 led at 12v vs 1 led at 5. Only really in the higher series resistance of the inductor because you need a bigger inductor.Perhaps even provide a jumper option, where by you can select 5v or 12v and swap out the power supply accordingly?
Just run at 12v.
Steff shield is currently running 3 channels of 7 leds at 24 volts and at about 500mA. (XTE warm white) No heating problems on the shield and very little heat sink on the leds.How many ma are your running your Crees at in this circuit?
I will do 7 leds as well with my 24 volt prototype.
I want to move to 24 - 48. but will probably have to settle on a 24-36v version and 36-48v version, the black regulator doesn't have a wide input range. I just need to change a resistor value to switch between the two variations.
One thing that will work for you is the input circuitry on the Dimmer channels, you should be able to put your square wave straight in.
The input filters use 10k and 0.1uF which gives 166 Hz. If you can give it a pwm above 15KHz then your filtering is done.
BOM is corrected, thanks for finding the errors.
Attached Files
- Steff2 BOM.zip 4.01KB 2 downloads
#31648 Powerful Aquarium Lighting
Posted by Magpie on 06 July 2012 - 10:30 AM in General Discussion
#31639 Powerful Aquarium Lighting
Posted by Magpie on 05 July 2012 - 11:00 PM in General Discussion
I know I am jumping in a little late here, but I just looked at the picture with the inductors. Aren't the ones on the left actually 33mH instead of 33uH?
I looked at this link coilcraft series
I must admit I don't know.
that's right.The bit in the bottom right corner is the black regulator right?
ps. I changed the logo, it will come out on the silkscreen.
I almost mounted the torroid footprints upside down, that would've been a disaster.
I just sent the gerbers off to seeed studio last night.
If you want I can send you some, I will test them first though.
#31592 Powerful Aquarium Lighting
Posted by Magpie on 04 July 2012 - 11:11 PM in General Discussion
#31591 Powerful Aquarium Lighting
Posted by Magpie on 04 July 2012 - 11:09 PM in General Discussion
#31278 Powerful Aquarium Lighting
Posted by Magpie on 28 June 2012 - 01:12 AM in General Discussion
But the Attiny will be Dip, just so I am sure that I can program it, I have never done an ISP header before and a cock up here would be catastrophic, the big inductors will be dip, and the connectors and fuse holder.
I think the program will be very small, probably the tiny261 will be fine.
I assume so but I really don't know.I have an avr ISP mk2 will that do the trick?
Those connectors look good (your favourite).
I think I want the screw in onthe flying lead and the L shaped black header pins, probably I will go for 5mm.
I will draw the pcb at 5mm.
#31272 Powerful Aquarium Lighting
Posted by Magpie on 27 June 2012 - 11:48 PM in General Discussion
#31271 Steff Shield
Posted by Magpie on 27 June 2012 - 11:36 PM in Project Showcase
#31234 Steff Shield
Posted by Magpie on 27 June 2012 - 12:05 AM in Project Showcase
I have posted a schematic, and now I am choosing parts footprints.
steff2
I am wondering whether to use the super torroids or to go with lower profile.
Also I am wondering what connectors to use.
But I have decided on the transistors and fets.
AHellene gave me some good tips for the Attiny.
#31141 Multithreaded Webserver and DataLogger
Posted by Magpie on 23 June 2012 - 01:01 PM in Project Showcase
I'm really glad you managed to find some use for the code, hope you make something really good with your project.
I know how hard it is to use somebody elses code, so that fact that you can use code from an unfinished, poorly documented project, mean that at least my attempt to write reusable code must be partially working.
Here is my liability waiver, It was a work in progress that got stalled because I couldn't get it right, then ran out of program memory.
I didn't mean to put it out to general view until I had fixed the bugs, done the binary upload and rearranged it neatly.
4.2 RC5 should give that extra space. But I was a bit disappointed that I still have a memory leak, so maybe it is my code.
My logger is still actually running but I have to cycle power as it crashes every 10 days or so due to the memory leak. I am fairly sure it is to do with being on the Internet because it used to run for over a month before I opened my gateway for it.
I still cant finish the Webserver/Logger due to my limited amount of time, but if you want to mention any bug fixes you see in the code then go ahead.
Biggest challenge so far was getting the multithreaded hardware calls synchonised to the hardware implementations, making sure the same relays doesnt get triggered by 2 requests at the same time.
Just use a lock for Thread synchronisation. I view any hardware as a resource and therefore because you can have multiple callers on different threads one has to wait for the other to complete.
I do love the challenges of multithreaded apps, fun to debug.
You seem to be making a real webserver.For handeling the webrequest that have no mimetype and are skipped by the webservice ive created a factory(mapper) that has all the availeble implementation for the hardware in the form of handlers stored in an hashtable.
All i have now are a relay handler and a logginghandler loaded in the hashtable.
I use a switch statement to find the correct handler based on the url fragments and then invoke doWork on the handler. I provide the doWork method with a string array of urlfragments. So all the implementation logic like calls to the hardware resides in the handlers. Ive created an interface for the handlers and a baseclass for the general work.
I know I should use JSON in projects but I tend to use XML due to my familiarity.
I don't quite follow, I haven't really tried 4.1. I have tried 4.2 RC3,4 and 5 no joy for me here.psps: fixing the n+ crash when using too much requests is easy by upgrading the firmware.. theres a bug crashing the n+ with an outofmemory exception in the 4.1 firware when theres plenty of memory left
I love the language C# I just wish one day in the future we could have a Jit compiler on the Netduino.
#30885 USB Audio Device - FINALLY WORKS!!
Posted by Magpie on 19 June 2012 - 01:02 PM in Project Showcase
#30883 Steff Shield
Posted by Magpie on 19 June 2012 - 12:56 PM in Project Showcase
#30795 Powerful Aquarium Lighting
Posted by Magpie on 17 June 2012 - 01:44 AM in General Discussion
#30769 Powerful Aquarium Lighting
Posted by Magpie on 16 June 2012 - 12:30 PM in General Discussion
The details are on my domestic lights project . It is based on the Attiny but with some improvements.
I hope this helps.<br>
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