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There have been 156 items by Magpie (Search limited from 27-April 23)
#39441 Powerful Aquarium Lighting
Posted by Magpie on 16 November 2012 - 02:02 AM in General Discussion
#39235 Powerful Aquarium Lighting
Posted by Magpie on 13 November 2012 - 02:24 AM in General Discussion
#39224 Powerful Aquarium Lighting
Posted by Magpie on 12 November 2012 - 11:29 PM in General Discussion
#39127 Powerful Aquarium Lighting
Posted by Magpie on 12 November 2012 - 05:42 AM in General Discussion
Attached Files
- SteffNearlyFinished_fixedcutouts.zip 25.51KB 3 downloads
#38664 Powerful Aquarium Lighting
Posted by Magpie on 07 November 2012 - 09:54 AM in General Discussion
pcb manufacturers
Or probably go with seeed.
Try editing the yellow pcb outline layer, I just looked at your board there is loads of room, but you may just have to reduce the copper pour a fraction.
Just fit (edit) the pcb edges to be 50mm apart. and move the copper pour to be at least say 1mm away. Move the fiducials too or you can just delete them.
Or when you are completely done with the other stuff I can do this step for you. I gave it a quick test it took just a few minutes.
the price from seeed is going to be $US 35.00 and if you waste $15 on something you dont want then you get free postage. The have a resistor book 805, but at $60 it is very expensive.
when you order from seeed you are not paying for service so do everything they say and it will be ok. I forgot my order number on one board but it didn't matter it still came. This time I put it under a big inductor so no-one could see it.
#38645 Powerful Aquarium Lighting
Posted by Magpie on 06 November 2012 - 10:23 PM in General Discussion
I think you should build something soon, but I have a different idea for you for control.
the netduino can talk SPI and the attiny can talk SPI. so you could drop the tlc5940s completely.
Just have the netduino set the dimming level direct to the attiny via SPI. The only trouble with this is you would loose one channel of PWM, giving you two outputs per attiny.
Although if you can handle a small blink while the communication is done you could have 3 channels.
Also I have never written any SPI code in AVR so you would be on your own there.
L1 will be ok, it just needs to fit mechanically and I think it will fit but it will be tight.
If it doesn't fit you can easily make it fit by soldering L1 just off centre or filing a small notch into the ic socket.
You understand you need to use a socket dont you? I am not sure if I made this clear.
I tried editing the pad offset, but every time I pressed OK, and went back in to the settings, it had gone back to zero?
Right click on the footprint and Open the footprint in the module editor. Set the working library to say 'Andrew' and put all your mods as you do them in here. Create a new part from what is in the editor and save it into your footprint library. At this point you can save it as you make changes. Once it is done then delete the old footprints and place the new footprints into your pcb. The tracks may be no longer connected, so reconnect them using your knowledge of grids and snap to.
One day when I get something looking good made I will post about my latest version, hopefully soon.
Yes I think before the final board is built you could optimise, but it is so hard to get the perfect design from scratch. It is iterative and I think 2 iterations will be your minimum.Let me know how you get on with your new boards, out of interest I know you have dropped a channel, but how small do you think I could realistically drop these boards to? I don't know if I definitely will, especially if these boards work, but I may lay it all out on one big board eventually with the TLC board built in and the power distribution for the 30 channels will be much more elegant and a lot of the connectors could be dropped. I could essentially get away with a GO! bus connector and a power plug, but this really is dreaming ahead!
If you get this first board made in small quanties, turn it on then I think you will find unexpected things, good and bad, especially in regards to the lighting aspect of it.
#38545 Powerful Aquarium Lighting
Posted by Magpie on 05 November 2012 - 09:56 AM in General Discussion
#38474 Powerful Aquarium Lighting
Posted by Magpie on 03 November 2012 - 11:47 PM in General Discussion
#38421 Powerful Aquarium Lighting
Posted by Magpie on 03 November 2012 - 11:47 AM in General Discussion
But if you just put a tiny square of insulator underneath, you can solder on both legs any way. It's a bit of a bodge but will work if the footprint is wrong.
Just going to few about 12 house now, what a Saturday! But I will make the amends and catch up later.
Does that mean you've been drinking for 12 hours? Don't fall in the aquarium, I am picturing some sort of James Bond evil villain type of aquarium.
what those atlas guys say about remote monitoring, is so true.
#38363 Powerful Aquarium Lighting
Posted by Magpie on 01 November 2012 - 11:56 PM in General Discussion
#38267 Powerful Aquarium Lighting
Posted by Magpie on 30 October 2012 - 11:41 PM in General Discussion
It is hard not to make a mistake on a board. You will definitely see improvements you will want.I added some drill holes, I will probably relay the board slightly once I have tested one working.
the Gerber lines up properly, I don't know about the .pho file.
Just make sure the foot prints of the stuff you order matches the ones on your board.
In steff2 I ordered D2Pak fets but had footprints for DPak fets luckily this mistake wasn't critical as I could force them on.
If you want to use Seeed Studio then I would scrape off approximately 1.1mm of the height of your board. It will save you money.
If you use someone else it may not matter.
Height : 30.4 -> 82.5 = 51.1mm
Width: 123.2 -> 261.6 = 138.4mm
Seeed Studio use 50mm increments for pricing.
In kicad there is a yellow pcb edge layer, right click on the lines and edit the y value to make it 50mm long.
Follow the instructions from Seeed Studio to the letter, for you first spin use green it is cheaper.
If you cut the board down to 50mm x 138mm then you can buy the 5cm x 15cm option from seeed.
PCB Cart is another place.
But I think UK has a lot of manufacturers too.
#38215 Powerful Aquarium Lighting
Posted by Magpie on 30 October 2012 - 01:42 AM in General Discussion
#37736 Powerful Aquarium Lighting
Posted by Magpie on 21 October 2012 - 11:09 PM in General Discussion
#37418 Powerful Aquarium Lighting
Posted by Magpie on 19 October 2012 - 08:48 AM in General Discussion
Attached Files
- steff35v.zip 44KB 6 downloads
#37401 Powerful Aquarium Lighting
Posted by Magpie on 18 October 2012 - 10:03 PM in General Discussion
#37372 Powerful Aquarium Lighting
Posted by Magpie on 18 October 2012 - 08:13 AM in General Discussion
#36036 Powerful Aquarium Lighting
Posted by Magpie on 26 September 2012 - 11:11 PM in General Discussion
#35937 Powerful Aquarium Lighting
Posted by Magpie on 25 September 2012 - 02:16 AM in General Discussion
I have done, I found it quicker now that I know what I am trying to acheive. If you had a lot of obvious connections then I think that the autoroute can do those fairly easily.I've been playing around trying to do the track widths, do you place all the tracks yourself
The ratsnest will dissappear as each node is fully connected. If you are using vias for higher current paths then you can use multiple.and if so how do you make sure you are connecting up correctly/ deal with vias?
Default for thin, 8mm for thick and say 3mm if it is carrying some current. But reduce these widths just for segments where it is necessary.What widths do you think I should be aiming for, for my thin, medium and thick traces and what clearances would I need?
Do your placement first obviously.
I haven't looked have you changed anything since last time I looked?In terms of my layout, which is similar(ish) to yours can you see anything that will/may cause me a glaring issue?
Sorry Andrew, I was actually Sailing all weekend, it was fantastic.
Did you sort out how to change track widths, I know it is very cumbersome.
You probably found this out already but
assign a track to a track type in the digital rules.
When you lay it out it will take the track width of the track type.
If you want to temporarily make some tracks a different width such as for the ground plane, Where the Kelvin connections carry a tiny current and the power ground has high current you can just change the track width for the track type(eg. High Current) while you lay that track. Then set it back to normal.
Also sometime you want to run the track thin into the pins but run it fat for most of the length.
First run it thin, then change the track thickness for the track type and right click and adjust the track thickness on the segments that you want thicker.
for the thicknesses
Connections into the processor only need to be thin. Power tracks make thick. Tracks on the ouput stage make thick as you can but thin them down as they feed into the component legs. It basically comes down to the current through the track. 8mm wouldn't be amiss joining the inductor to the Fet and the diode, if you can fit that much.
I quite liked my posistioning of the components, to minimise track lengths for the high current tracks. But maybe you want the connectors to be organised differently.
As for the Kelvin connections run them as pairs or threes lik it did. The only place the ground of the kelvin connection touches ground is at the sense resistor.
the point is we want to measure the voltage of the ground at the sense resistor compared to ground at the micro, but using only the minimum current we can to do it. (Conceptually tricky). Also we want the minimum induced noise so we run the differential inputs right next to each other, for as long as posible.
Hope this helps
#35299 Powerful Aquarium Lighting
Posted by Magpie on 15 September 2012 - 01:12 PM in General Discussion
#34664 Powerful Aquarium Lighting
Posted by Magpie on 04 September 2012 - 11:18 PM in General Discussion
#33122 Powerful Aquarium Lighting
Posted by Magpie on 04 August 2012 - 11:58 PM in General Discussion
Firstly, put your Kicad stuff including libs and mods into source control, if you are going to work effectively this is a must, being a programmer you probably already use source control, it is so easy to make a mistake by clicking the wrong button, that rollback will save you and give you clues into how it all works and tell you what has been changed.There are foot prints for this type of cap but none that are exact so I wanted to edit the component to make one for my cap, but couldn't workout how to do this in the editor. The lines didn't seem selectable and the couple of pdfs I read didn't seem to help much either?
Just to start by giving everything standard footprints. Doesn't matter if the footprints are wrong as long as the pins are the same.
Then in pcb editor right click and edit module on the components that need changing. Then on each pin you can edit by right clicking. The pads are normally simple shapes, so you can edit the them by just changing the sizes and offsets in the text boxes.
If you need a complicated pad shape you can make it as two or more separate pins but give them the same pin number. This is a strange but necessary work around and it does work fine.
Work out how to save these modified mods into your own mod library and then associate them.
Did you see a youtube video on Kicad, I found one in particular it quite useful.
the footprints for the caps don't need to be exact, if it roughly good enough it should solder ok, you are better off using a standard footprint because you might change caps anyway.
Also there is a difference on components between the actual footprint and the solder pad needed. the solder pad is normally a bit bigger around the edges of the component so you can stick the point of the soldering iron onto the pad itself.
that's what I did, the caps need to be close to the processor and the resistors are not so critical. I would go with that unless you have a specific reason. The bigger components are easier to work with.Am I right in saying all the resistors should 1206 and all the other caps should be 0805?
ps. the reason I chose 4.7uF through hole is because I had 100 of them already.
#33111 Powerful Aquarium Lighting
Posted by Magpie on 04 August 2012 - 12:15 PM in General Discussion
#32993 Powerful Aquarium Lighting
Posted by Magpie on 02 August 2012 - 01:51 AM in General Discussion
Attached Files
- Steff2AS6.zip 51.7KB 1 downloads
#32978 Powerful Aquarium Lighting
Posted by Magpie on 01 August 2012 - 01:29 PM in General Discussion
they seemed to be $6.00 each or was that a pack of something.Found these they seem relatively cheap and available what do you think?
Try PCE3340CT-ND I think you should be able to get something for around 50 cents, you can probably go smaller 33uF on these if you want.
from memory it is in devices and called cp1In terms of the cap symbol, which library do I need to look in?
Also you mentioned in terms of the library that I may need some files? Do you think this is the case and is this for the PCB design as opposed to the actual schematic?
more so in pcb editor, these is an excellent pdf that is built into the toolbar on pcbeditor. use that to help find footprint names
I have the channels 1 and 2 current sensing and stable.
Now I have init/boot problems and channel 3 I cannot get to current sense.
#32960 Powerful Aquarium Lighting
Posted by Magpie on 31 July 2012 - 11:44 PM in General Discussion
This is just a bypass capacitor for the whole board. It's size depends on the power used by the board and the length of wire to to power supply and the power of your power supply.C21 larger electrolytic capacitor of 50uF, I have been unable to find a suitable part even in stock on digikey, am I missing something or is this a fairly heavty cap? Can you suggest any examples any where?
Anything from 10uF to 220uF would be fine, I suggest 50uF but it wont make a difference.
Also its voltage rating doesn't need any high voltage either. 16v is fine but 25v is good too. Remeber it is electrolytic not ceramic. For a computer analogy, the ceramic is like your ram and the electrolytic is like your hard drive. They are often in parrallel. It should be easy to find. The pdf schematic component is wrong is should show a curve on one of the plates and a plus sign. They are unipolar and need to be orientated correctly.
Yes that is fine.Almost there with the schematic, although I have just been changing the values of the components is this ok?
The diagram looks good otherwise,
dont worry about the DRC on those last things, you can safely ignore it.
If you really want to fix it you can edit the module and then edit the pins to be power in or whatever satisfies DRC.
Both of those are standard (12 mils x 6 mils) and (8mils x 5mils) dimensions with mils being 1 thousandth of an inch.On the topic of foot prints is there a standard for all the resistors I remember you mentioning an issue you had 0805 and 1206 I think?
Don't go any smaller than 0805 and I would use 1206 out of choice as it will be easier to measure and fix. I used 805 on the caps so I could fit them in nice and close to the ATTiny,
and 1206 on most of the resistors. When buying another thing to watch is the tolerance, but in this case it doesn't matter too much. Though it is easy to get 10% on ceramic caps and 1% on resistors so I wouldn't settle for less, incase you have spare and want to use them on another job.
After that I reckon you are done.
Now assign and/or make footprints and do the pcb layout. I find there is a fair bit of back and forth between metric and imperial while I do and check foot prints.
But I still haven't got the firmware to do the differential ADC inputs, with the 32 x Gain,
I have measured current but only as a one sided input, and because you get no gain I only get a tiny voltage.
I will try again tonight. My feeling is that it should work so it is only a matter of time.
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