8 ms·
Very impressive. I would have thought that this sort of RF work is outside the hobbyist realm. The rest of the blog is equally impressive — 217-ball BGA solder
by jwr 12y ago
Very impressive. I would have thought that this sort of RF work is outside the hobbyist realm.
The rest of the blog is equally impressive — 217-ball BGA soldered in a home-made reflow oven?
- sliverstorm 12y agoHe's an EE student and clearly a pretty good one, so IMO he is beyond the typical hobbyist realm. The nebulous space of the professionally trained tinkerer. bunnie huang comes to mind as another example of this sort. When he cracked the Xbox, he had training & equipment that hobbyists don't have- but he did it in the hobbyist spirit.
- rasz_pl 12y agoToday you can get access to equipment thru hackerspaces, so its not even all that expensive.
- sliverstorm 12y agoIt still depends on what you want to do- sniffing high speed memory busses and work in reflow ovens are still out of reach of most hackerspaces I have seen.
- VLM 12y agoYou can use a rework station (basically a low air speed hot air gun) and wave it around. You'll need one anyway. Maybe $100 minimum. The biggest problem with building your own reflow oven is the conversion kit mfgrs want their profit off repacking and marking up retail parts (arduinos, SSRs, thermocouples, etc) and of course you need a donor oven (maybe $50 at walmart?) so you end up paying like $150 to bodge something together.... while over on ebay, you can get a brand new professional reflow oven shipped to you for a bit over $200 from the usual gray market sellers. Supposedly they work pretty well and I'll eventually buy one. Or maybe they're junk. If I get closer to buying one I'll research it in detail. I've done the skillet / hot plate + pan thing. Make a sling of kapton tape (you do have kapton, right?) because otherwise you're going to melt the solder and then stand there thinking "um, ok, so now how do I remove a PCB thats too hot to pick up, and leaving it on the hot plate for 30 minutes while it cools down exceeds all sanity" Even with lead free solder paste I think its unacceptable to share hot plate with kitchen and lab. You can put the PCB on a steel spatula and the whole works on the hot plate and that works pretty well if you don't do kapton. (edited to add and you can easily spend more than the cost of a reflow oven by trying to avoid buying a reflow oven, because a non-contact IR temp meter is a handy accessory to the hot plate technique, but if you need to "charge" the cost of a IR thermometer to the hot plate project, suddenly its cheaper to just buy an oven...) Hand soldering SMD is very easy but slow. Faster than hand soldered thru-hole, but still pretty slow. I have done 0201 RF parts but it was not really any fun at all, the bigger stuff is much easier to hand solder. And no caffeine allowed.
- sliverstorm 12y agoI skipped out on making my own oven back in the day; results seemed spotty. I'm glad to hear they are more feasible now. I stuck with the reflow station I had access to. Nice to see those have come down in price too. I still remember trying to do 0201 with the reflow station, accidentally blowing caps right off the board :)
- rasz_pl 12y agoyou mean like this? http://scanlime.org/2009/09/dsi-ram-tracing/ http://scanlime.org/2009/09/dsi-ram-tracing/
- sliverstorm 12y agoYeah, kinda like that. If you're curious; http://www.xenatera.com/bunnie/proj/anatak/xboxmod.html http://www.xenatera.com/bunnie/proj/anatak/xboxmod.html http://bunniefoo.com/nostarch/HackingTheXbox_Free.pdf http://bunniefoo.com/nostarch/HackingTheXbox_Free.pdf The PDF has the full story, the first link has some neat photos including die shots.
- rasz_pl 12y agoThen its easily in reach of average hobbyist. You dont need anything super expensive, the one I linked was done using $30 FPGA board.
- sliverstorm 12y agoGood lord, are FPGA's that cheap now? I remember the absolute bargain-basement slow-as-bricks FPGA board running $100.
- jjoonathan 12y agoKinda. There's a huge price split depending on if you just need GPIO or if you need transceivers (serial above 1GHz). If you just need GPIO $30 is reasonable. If you need transceivers, $300 would be a bargain.
- rasz_pl 12y agoone used in my link ~$35 http://www.ebay.com/itm/XC3S500E-XILINX-Spartan-3E-FPGA-Evaluation-Development-Core-Board-XCF04S-FLASH-/231345080693 http://www.ebay.com/itm/XC3S500E-XILINX-Spartan-3E-FPGA-Eval... smallerr one $16 free shipping http://www.ebay.com/itm/ALTERA-FPGA-Cyslonell-EP2C5T144-Minimum-System-Learning-Board-Development-Board-/200942146349 http://www.ebay.com/itm/ALTERA-FPGA-Cyslonell-EP2C5T144-Mini... programming dongle ~$5 http://www.ebay.com/itm/USB-Blaster-Programmer-Cable-For-FPGA-CPLD-JTAG-Development-Board-XA-/191332719538 http://www.ebay.com/itm/USB-Blaster-Programmer-Cable-For-FPG... We live in amazing times for hardware developers. Stuff that was out of reach 10 years ago is peanuts right now.
- MrBuddyCasino 12y agoEvery Hackerspace I've seen has one of those modified pizza ovens with an Arduino controller attached. Its really cheap to do nowadays.
- hwillis 12y agoIf you think thats cool, MIT students have been making Synthetic Aperture Radar (which uses "chirps" of radio waves and measures the time of flight) for the past few years, with enough resolution to image groups of push pins. Oh yeah, and it works through walls. Radar can seem like a black art but simulation software and a bit of knowledge makes simple stuff like this perfectly doable. http://ocw.mit.edu/resources/res-ll-003-build-a-small-radar-system-capable-of-sensing-range-doppler-and-synthetic-aperture-radar-imaging-january-iap-2011/ http://ocw.mit.edu/resources/res-ll-003-build-a-small-radar-...
- toomuchtodo 12y agoI think its awesome that GPS is regulated (Speed or Altitude) with export controls, but you can build high-quality, weapons-grade SAR at a college. The future is incredible.
- trhway 12y agocool footnote there: "This work is sponsored by the Department of the Air Force under Air Force Contract #FA8721-05-C-0002." well, you can build high-quality un-locked GPS receiver as a DIY too :) http://www.aholme.co.uk/GPS/Main.htm http://www.aholme.co.uk/GPS/Main.htm
- toomuchtodo 12y agoWhen that link first hit HackerNews I thought, "There are some incredible people out there doing cool stuff".
- hwillis 12y agoHah, there's a lot more to weaponized/spy SAR than just the radar; you have to have very good measurements of your movement as you record. It can be improved algorithmically as well but data is king
- InclinedPlane 12y agoWell, funny story. When North Korea put up their first satellite it used GPS. Which, when you think about it, is pretty funny because denying entities like the North Korean regime use of GPS in that use case is a major reason the export controls exist.
- rasz_pl 12y agoSoldering BGA is not all that impressive, routing proper pcb for one is. Contrary to popular belief soldering SMD in general is way easier than dip, all you need is an oven/hot plate/hotair gun and solder paste/flux. Magic happens due to molecular surface tension instead of your manual dexterity.
- jrockway 12y agoYeah. I actually prefer prototyping with SMD these days, since everything is super cheap, easily available, small, and easy to solder. You basically apply flux liberally, heat up the pins, apply solder, and surface tension does the rest. (The whole "never melt solder with your iron, heat the pin and let it melt the solder" no longer applies. You can put a big ball of solder on your iron and just sweep it over the component you're soldering. There's plenty of flux in play because you drowned everything in flux.) BGA is outside my abilities, however.
- thrownaway2424 12y agoIt's a shame the way the impedance-controlled traces on this board turned out all janky though. I get boards done at Sunstone and I guess the price might be higher but the results are good. I think most people under-estimate the degree to which you can click a button on your computer and get manufactured goods in the mail. Even for small runs like ten boards I can cost-effectively get the boards fabricated and stuffed and delivered to my desk in a day or a few days depending on how much I'm willing to pay.
- conesus 12y agoHow much are you paying per in^2 to have Sunstone fab a board? Are you paying for assembly? OSH Park, as used in the article, is only $10/in^2 for 4-layer.
- thrownaway2424 12y agoIt strongly depends on how many you order, since nearly all the cost is in the setup. A 10 in^2 2-layer board is ~$300 for ten boards.