A simple, actually not even worth mentioning, USB to CMOS level EIA-232 (RS-232) converter.
Includes Parallax-Propeller-Reset (aka.: Propeller-Clip).
A typical example of wasting invaluable development time for completely other stuff...
Until now, I included the FTDI in every Propeller based board, I created. This time, I needed something more
"universal" (...) and detachable.
Two hours should have been enough. Something made it three days...
Lab's Law
DAY1:
- created schematic, incl. library, within 1 hour (incl. 1 coffee)
- created layout, within another hour (incl. 1 cold coffee)
- hit 'save'
- ***WHAM*** system off, lights out, a dog barks
- circuit breaker...
- found no fault but needed to detach all switching PSUs; 1 hour
- next, a coffee; machine: "system fault, call service"
- immediately disassembled the service friendly machine (triangular screw heads... idiots!); 2 hours
- found fault 1 hour later; a thermal sensor decided to leave the brewing unit, dangling around
- no problem, thermal adhesive is in the lumber-room
- middle row, undermost box of 6, all stacked on each other (thanks, DYMO!)
- 5 boxes on the floor, emptying themselves (do not trust paper, use tool-steel...)
- 4 hours pick-and-sort
- day gone...
DAY2:
- no coffee; tea, fine; floor, child, toy-car, tea, floor getting nearer...;
- at least, I was awake; cleaned up
- forgot to take out adhesive off the box
- middle row, undermost box of 6, all stacked on each other; success!
- glue dried up
- car, parking place, store, car, parking ticket; 1 hour
- repaired machine, had coffee; 2 hours, but relaxing
- back to layout, hit SAVE, success; 1 hour
- turned on milling PC: "no operating system"; WHAT NEXT?
- removed 2 others PC on top, disassembled the crap, refitted S-ATA cable with 2 min epoxy (suffer, suffer!)
- turned on milling machine, *click* nothing
- actually it WAS on, already; at least, I then knew why the circuit breaker triggered the day before...
- not that heavy (70kg), but completely surrounded by other equipment, including the 3 PCs from before...
- spent rest of the day repairing the machine (standard fault, switching PSU, electrolytic capacitors)
DAY3:
- had coffee; nothing happened
- milling PC and machine ON; nothing extraordinary happened
- prepared machine, PCB, program, homing axes...
- ***WHAM*** there went 45 bucks (EUR); a brand new LPKF RF 6mil end mill
- forgot to attach the z axis home switch, that bad day #2, before
- another mill, another try; success, but another two hours gone...
- milled out board manually on another machine
- cleaned that nasty, sticky FR4 above the bathroom sink
- *plop* down the drain...
- took off U-pipe, found PCB, matchbox car and a barrette
- needed coffee... only 1l milk left? -> children built an "invisible" submarine; creative but annoying...
- carefully, virtually trembling, soldered PCB
- success; blackout
Hardware
The layout was created for milling machines (and without solder resist):
- one power connection was intentionally left out (avoids short circuits under USB plug)
- all attached FTDI pins were made a little longer (easier soldering)
The four RS-232 pads (X1) were made for soldering on a 2.54mm header.
There is nothing more to say about this ... little thing.
Use the library/schematics/layout as a quick starting point for your own stuff...
the damn schematic
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the f****** layout
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NOTE 11/2010:
What can you do, if all your milled prototypes were stolen by software guys?
Right. You won't ever see them again (the prototypes =), make a series...
the (almost unchanged) schematic
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a nicer, smaller layout
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Useless Pics
three days after...
SPIF TORX-receiver on-board
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a closer view
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and the connections
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Download
MiniFTDI:
Includes:
- schematic (PDF)
- schematic (SCH)
- placement (PDF)
- layout (BRD)
DOWNLOAD: miniftdi V1 V1.0 (biiig and longer pads (for milling))
DOWNLOAD: miniftdi V2 V2.0 (smaller)
The driver can be downloaded, here.
ASkr 12/2009 initial (and forever lasting ;-) version
ASkr 11/2010 updated docs for smaller V20 version
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