> On another note, have any of you used spring-pin connectors for > programming/debug connectors to save space and BOM cost? I have been > thinking about how I would design my own spring-pin programming
We use Mill-Max 821/823 series to do AVR ISP program at work. I can get you the exact number when I get back to the office on Monday. Our jig kind of looks like a mini-sewing machine. Lever press the six pin connector into the holes on the board. The levers are a standard "hold down clamps" from McMaster Carr: http://www.mcmaster.com/#hold-down-toggle-clamps/=dld9w1 We also build Bed-Of-Nail spring-probe test fixtures out of blocks of hard wax, and mill the holes for individual spring probes to hit test points on the boards. Same Hold-Down-Clamps are used here as well. Every switch point, power supply connector, etc. has a test point pad that hits a probe, for our board testers. Something I've wanted to do Real Soon Now is make a universal board tester out of a Actel Fusion FPGA (Have embedded ARM cores, A/D, D/A, I/O etc), were I load a program for the board and hook up one of the above bed-of-nails for the target under test, rather than building testers for each product. A mini-version of the old Wayne Kerr board testers I use to work on. Same fixture would be used to program the target as it is tested. Typically a test a bootloader and a self-test program is loaded into the micro during board testing. A real application will get loaded, via bootloader, on the production floor before final shipment. Something from my blog: http://blog.designer-iii.com/avr_isp_spi/20081116-10511-Digital-MEMS-Accelerometers-will-not-work-with-AVR-ISP-using-SPI "You are supposed to isolated the AVR ISP pins with 1k resistors, as the Atmel documentation shows". This is true. However that takes four resistors per board, on a board that already did not have enough space. Also at 50,000 units per year, with an design lifetime of five years, that is 1,000,000 resistors. After a while these resistors start to add up to real money, for what is a single event at manufacturing time. Design for Manufacturing always should be given consideration. I'll show people your T-C parts next week, might save us some room too, thanks. -- http://blog.softwaresafety.net/ http://www.designer-iii.com/ http://www.wearablesmartsensors.com/ _______________________________________________ geda-user mailing list geda-user@moria.seul.org http://www.seul.org/cgi-bin/mailman/listinfo/geda-user
