You can take the next comment with a grain of salt, since the owner of OSH Park is a friend of mine,
Wait, so we're not friends too? :) :D [/quote] LOL! Alright, you got me there. Full disclosure: Laen and Ian are both friends of mine so be equally skeptical of my opinions on both PCB services ;) Personally, I plan to use them both depending on the situation.
BTW, I did some bring up on the DirtyPCB board I built and so far I've got the processor programmed and blinking an LED so I'm pretty happy. -scott
[quote author="CyberPK"] What do you think about? :)[/quote] The drills in the gerbers are fine so the misalignment is due to manufacturing tolerances. They really aren't bad and certainly suitable for prototype work. The fab sent 12 boards and they all look pretty much like the one I did the photo of. One board had a couple of pads where the solder tinning was sort of blobby but that was easy to retouch. The QFN chip is .4mm pitch and the solder mask held between those pads. Overall, I am quite happy with the quality for the price. Turn around time was relatively good as well. You can take the next comment with a grain of salt, since the owner of OSH Park is a friend of mine, but DirtyPCB quality clearly isn't up to the level of OSH Park boards and the turn around is slower, at least for me in the US. But if you need cheap prototype boards and you can wait a bit longer, then DirtyPCB seems like a good option.
[quote author="matkey"]Is that a Nordic chip footprint by any chance?[/quote] Yep, an NRF51822. I've been working with the Nordic dev kit for that chip but I wanted some easier to use breakout boards. When Ian asked for some boards to test the DirtyPCB web site, I didn't have a 5x5 design ready so I pulled a design from the web (https://github.com/nocko/nRF51-devel). I built one board last night but haven't had a chance to test it out yet. Hope it works ;). -scott
I got my Dirty PCB order a couple of days ago. Not bad turn around to the US West coast. I've had a quick look at them and they look pretty good. I'm planning to build one up tonight.
I did add G70* manually, but maybe it wasn't necessary with your latest changes. The INCH keyword came from gerbers generated by geda. I'm not sure it is used in gerbers from other CAD programs. I only see it in the drill file in gerbers from KiCAD. -scott
[quote author="NsN"]I'm trying to give it a go, but so far I'm always getting "GML file missing units". I'm using an old project of mine, with gerber files that worked with seeed, elecrow and OSH Park. [/quote] Yeah, I'm having the same problem. I haven't found a fix yet although I've tried a few things like including G70 which is supposed to say that the units for the gerber are inches. The gerbers I'm trying already had an INCHES keyword but that didn't help either. The gerbers view fine in several gerber viewers.
OK, issue created. BTW, I suspect that these changes would also enable the OLS client to run on other ARM based single board computers like the BeagleBone Black. But I don't have hardware to test that. -S
I've started to use a raspberry pi as a computer on my bench (it is small, quiet and cheap). I mainly wanted something to capture and plot data from instruments via GPIB and serial and do some simple browsing and viewing (like viewing assembly diagrams while placing parts). But sort of on a whim, I decided to see if Jawis OLS client would work on the pi. The latest Raspbian distributions have java 1.7 preinstalled so there wasn't much to do except to download and unpack the latest OLS client. In fact, it almost works out of the box. The one issue is that the version of JNA that Jawi packaged with the OLS client didn't include the appropriate JNI shared library for linux-arm. However, the latest JNA builds do. After some fumbling around, I finally understood where the JNA stuff was packaged up in the OLS distribution (it is in plugins/org.rxtx-2.2.0-10.jar). I replaced the JNA code in org.rxtx-2.2.0-10.jar with the contents of jna.jar from https://github.com/twall/jna and repackaged a new org.rxtx-2.2.0-10.jar. OLS 0.9.7 then fires up and seems to run fine. I'm using an early pi with 256M of memory so it takes a little while for OLS to first come up. I suspect that a newer pi with double the memory would be faster. But once it is running, it seems quite usable. All the measurements and markers seem to work and the performance isn't bad with the interactive measurement pane. I tried to capture a simple square wave test signal at 200MHz capture rate and it worked just fine. I also tested the protocol decoders using the Test Device I2C data and that worked fine also. [attachment=1] Overall, it works better than I expected and, in fact, works well enough to actually use in practice. I've attached the new version of org.rxtx-2.2.0-10.jar. If you want to try OLS out on a pi, download and unpack the latest linux version of the OLS client and then unzip org.rxtx-2.2.0-10.jar into the plugins directory. After that, you can just use run.sh to fire it up. I modified run.sh to ask for less memory when java is starting up but I don't know if that really matters or not. -Scott
[quote author="hlipka"]OLS already does this (I think its called 'compressed mode' or so, don't remember exactly at the moment :([/quote] It is called run length encoding. It does help in some cases where the signals are changing sporadically but you need high capture rates when they are changing.
Oh, and one other thing about those dental/surgical loupes. They are really made to attach to prescription glasses if you need them. And you can't use them with progressive bifocals. The best thing would be to attach them to single vision glasses with a fairly close focal distance (like glasses for reading computer screens). If you don't need vision correction, then you can just use the frames with plain glass lenses that the loupes come attached to.
I've got one of those dental/surgical loupes (3.5X and 420mm focal length) and they are pretty good for some kinds of work. You don't have to get so close to the work that you practically burn your nose when you are soldering (like you do with a normal 3.5X visor). The one downside is that the field of view is pretty narrow. On the other hand, you can easily peer around them to get a wider view. The really professional models are several hundred dollars but the $40 ones from eBay don't seem too bad optically.
