hw/mpserial
11 years agoAdd the USB resistors back in origin/HEAD origin/master
Keith Packard [Sat, 29 Dec 2012 07:56:00 +0000 (23:56 -0800)]
Add the USB resistors back in

These can protect the board from an accidental cable mishap, so we'll
put them in just in case.

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoOops. Got the FT230 D+/D- lines swapped
Keith Packard [Sat, 29 Dec 2012 07:23:54 +0000 (23:23 -0800)]
Oops. Got the FT230 D+/D- lines swapped

Flip them around, and remove the 33ohm resistors at the same time.

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoPlaying with other resistor values
Keith Packard [Sat, 29 Dec 2012 06:39:14 +0000 (22:39 -0800)]
Playing with other resistor values

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoUpdate resistor values to match what works. Add LED.
Keith Packard [Tue, 18 Dec 2012 06:55:22 +0000 (22:55 -0800)]
Update resistor values to match what works. Add LED.

Testing revealed that the phototransistor appears to need quite a bit
of current to get the rise time within reasonable limits. Change the
resistor feeding it to 680 ohms (from 3.3k). This also required
changing the op-amp bias voltage from 1/2VCC to 90% VCC. Swapping in a
1k resistor for the 10k there fixed that nicely.

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoAdd outline
Keith Packard [Fri, 14 Dec 2012 19:15:58 +0000 (11:15 -0800)]
Add outline

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoAdd some silk to the back side
Keith Packard [Fri, 14 Dec 2012 06:09:13 +0000 (22:09 -0800)]
Add some silk to the back side

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoFinish the first version of the board
Keith Packard [Fri, 14 Dec 2012 06:01:40 +0000 (22:01 -0800)]
Finish the first version of the board

Signed-off-by: Keith Packard <keithp@keithp.com>
11 years agoImport preliminary schematic
Keith Packard [Fri, 14 Dec 2012 02:37:30 +0000 (18:37 -0800)]
Import preliminary schematic

Signed-off-by: Keith Packard <keithp@keithp.com>