Fertigung eines USB2LPT-3

Uploaded by Studiosum on 05.06.2011

USB2LPT production
A H.V.A. video
Part 3 of 3
USB MiniB receptacles — unprepared yet.
For the required edge mounting, the leads must be straight, not angled.
So I'm bending the upper three leads straight.
This is already done for solder-yourself sets,
this part is then easier to ship.
Then shorten all leads, the upper row by 3 mm, the lower by 1.5 mm.
For right-angled mounting of the receptacles into the PCB edge-gap, I made this wooden aid.
Oops! The component doesn't fit!
A remaining ridge from milling is too large here and must be removed beforehand.
With a utility knife.
It's not so easy to make this procedure visible for you …
… without cutting into the fingers.
Now it fits.
The spring force of the three upper leads of the receptacle uplifts the component looking like an open crocodile mouth,
a simple holding-down sheet defeats this effect.
Now I shift the PCB toward the receptacle and adjust it to be parallel.
Soldering iron to maximum temperature, then soldering outer edges.
For optimum solder fluxion, put solder wire to heated component body,
not to the PCB and not to the iron.
Now the same procedure for the other side.
The device cannot drop accidently. The thermal conduction of the body isn't sufficient to melt both solder joints simultaneously.
Now bend the leads to the pads …
… and solder with reduced(!) iron temperature.
For the other side, bend the leads to the pads …
… and then push them a bit as you can see here.
Then solder again.
(The right lead isn't connected so there is no need to solder it, I do it only for beauty.)
For crystals there are special two-hole plastic washers for insulation …
… for keeping their metallic housing off the PCB's vias.
I'm stingy and use a piece of adhesive tape.
Prick the holes with any needle.
Assemble the crystal …
… and solder it. My left hand holds both the component and the solder wire reel.
Now only the LEDs are missing.
The device is now ready for programming.
For this we need a USB cable …
… with Mini-B connector.
So plug the cable to the device …
… and the other end to the computer.
There appears “Cypress EZ-USB FX2 (68013) without EEPROM”.
Start “Brenner.exe {pfad\}usb2lpt2.iic”
This console program downloads the firmware to the microcontroller's internal RAM.
Then it will renumerate™ the device to a USB2LPT. Enter a serial number or simply nothing.
The programming itself (i.e. filling the I²C EEPROM) is pretty fast.
This is my firmware, 32 times faster than Cypress' demo software.
Then “h#s USB to parallel converter (LPT3)” appears in Device Manager.
The prepared D-Sub shells: Mounted, checked, drilled and labeled, the latter on both sides.
Open the shell and keep all 10 parts
The drills need to be deburred.
It's already done for solder-yourself sets.
On inner side I counterbore the drills. So the LEDs can be skewed a bit for mounting.
This cardboard construction is my height gauge for LED mounting.
You see noticing the serial number into bottom shell half.
Assemble LEDs; pay attention to right polarity and color!
Assemble the upper shell half, the holes give the fit and position for the LEDs
Now I shove the LEDs entirely to their inner edge.
The height gauge will shove the LEDs back to their final (and the same) height.
Now solder one lead of the LED …
… then check for equal height …
… then solder the other lead.
It's complicated to move LEDs already soldered on both leads, therefore this intermediate step.
In such a case, you may destroy this device,
because LED's are sensitive to heat in conjunction with force to their leads.
Mounting the D-Sub shell: See video how to do it best.
The LED assembly again: Yellow upper, Anode left,
Blue lower, Anode left too.
You can see an “LPT Checker” right.
Start of application “Kurzschlusstest.exe”
All LEDs should go off.
Answer all questions with “Yes” or “No”.
Now you can use this device as replacement for the missing parallel port.
Are you one who have never seen such a socket at your computer before?
This device is not very suitable for JTAG programming adapters and almost never for dongles.
But for all other it sould work:
amateur radio equipment, stepper motors, PIC and AVR programmers etc.
The End.
You saw the documentation: “USB2LPT production”
Recording, editing, equipment: Viktor Fährmann
Idea, production: Henrik Haftmann
Recording device: Minolta Exilim EX-FH20
Editing software: Microsoft Movie Maker
Home page: http://www.tu-chemnitz.de/~heha/
Music: … (see movie)
Closed captions made by Henrik Haftmann