Omega2 expansion dock alternative?
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Runs at less then 200 ma but you should allow for up to 500 ma on bootup.
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The problem I've been finding when it comes to making a homebrew dock has been in sourcing headers to attach the Omega2s, assuming you don't want to permanently solder it in place.
Can't seem to find anywhere easily accessible (for Australia) that has 2mm pitch header sockets available for 16 pins (or even a combination of fewer pins added together). Or at least not without taking the price higher than it would cost to buy sufficient expansion docks directly from Onion.Has anyone found a cheap source for 2mm headers? Either through hole or surface mount would be okay, would just need to adjust the circuit board to deal with what's available.
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Yes, the 16 hole 2mm headers are a bit rare. Is $1 per Omega delivered to your mail box cheap enough? Available here in a few days, after the Rooster holiday in China ends - http://www.ebay.com/itm/182057549028?_trksid=p2057872.
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@Costas-Costas said in Omega2 expansion dock alternative?:
Runs at less then 200 ma but you should allow for up to 500 ma on bootup.
The power spikes when the wifi is active. I've seen about 420 mA on one board and the absolute peak is probably a bit higher. There seemed to be a significant difference between the two boards I have, about 350 for one and 420 for the other, so I'm not sure how representative that would be.
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@Ken-Conrad That's a good find, 16-pin ones are hard to find. One could also order 20-pin headers and just cut off the excess pins. They seem to have a really good selection of all sorts of sizes on Aliexpress, though no 16-pin.
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@Ken-Conrad said in Omega2 expansion dock alternative?:
Yes, the 16 hole 2mm headers are a bit rare. Is $1 per Omega delivered to your mail box cheap enough? Available here in a few days, after the Rooster holiday in China ends - http://www.ebay.com/itm/182057549028?_trksid=p2057872.
For what it's worth I got 2 mm 16 pin headers from this supplier and received them to the US in 8 days. That's probably not typical though.
Prior to getting 2 mm bits, I built up a jig on a 0.100" perf board with individual sockets for power pins, serial I/O, and locating sockets on the corner pins (2 of which are GND anyway). I put the socket headers on the Omega, inserted them through the closest hole in the 0.100" (so they were angled to go from 0.100" to 2 mm), and soldered in place. The socket headers I had were cannibalized from a wire-wrap DIP socket I had in the junk pile.
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@Mark-B That is also a nice find for a 2mm headers supplier, at half the price I paid per header. Sometimes a lower price means the slowest mail from China, perhaps not with this seller. From either supplier will have to wait for the end of Chinese New Year, ie after ~2/8 to order.
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@Ken-Conrad @Mark-B They look perfect. And I suppose I can blame Chinese New Year for not being able to find these or anything similar. Looks like ebay hides all the items for sellers that go on holiday
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@Keij-H eBay search for the listing should still work, but you can't order until the seller turns off the 'vacation notice'.
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@Ken-Conrad Oddly enough, if you go to the "see other items" or "visit store" links, even from an existing directly linked item like those above, ebay claims that no items are available. You can only find the item if you already know the item number. (It really feels like I had to use the word 'item' too many times in this post.)
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Maybe you can try to order this PCB and do by yourself https://oshpark.com/shared_projects/GOi9e1ZF
And have something like this http://jcprojects.tumblr.com/post/155454738769/my-omega2-onion-shield-using-a-ams1117-for-33v
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@Keij-H I just order the full 40pin lengths and cut them to suit. You lose a socket wherever you cut it, but you can file and smooth it out enough to make it not look cruddy. Plus it's the cheapest way to get them!
i.e. 10pc 1x40 2mm header for AUD$3.74 including postage from eBay!
Oh, and I have some of those boards that manuti manuti has linked
coming (are in the post should should turn this week hopefully):edit: scratch that, had just arrived!, and they do look really handy if you don't have a dock, and want to shove an Oak onto a breadboard or just have an easy way to power it.
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@Peter-Feerick I order 3 boards to OSHpark and the female pin header shared by @Ken-Conrad
Thanks!!!
Is interesting to know how this alternative dock works
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@manuti-manuti Well, I take that back... they had actually arrived in yesterdays post so they had actually arrived when I wrote that I was expecting them!
They look really good. I had also ordered some breakout wings which just do the conversion from 2mm to 2.54mm. So I now have the option of straight-out breakout adaptor (which should be be very breadboard friendly as you can have the wings go under the Omega2 and make more of the breadboard accessible) or a quasi dock with USB power and a serial connection. Nice! Just went and ordered a load of bits from eBay to populate the board... hopefully I got all the right bits!
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I want to share two more DIY breakout board I found:
- https://oshpark.com/shared_projects/boUh3Ezt very similar to the previous one but maybe can be populated with bigger diveces.
- https://pcbs.io/share/4KEo9 small but fully of potential.
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You can look into this CE onion omega screw terminal Board.
Onion Omega ST
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I used seeed studio for pcb fabrication for it is much cheaper than oshpark and pcbs.io, is it possible for me to download the design files and sent to another pcb house to get manfactured?
