Test electronics: 17:07 (tech_notes#301)

1] Kasparov chess interface:

8x8 touch switch interface potentially for FPGA.

we have 8+8 wires from switches - these are pulled high (6v) to low (0.5v) when switched

2] 4016/4066 digital switch tests:

On breadboard, we can switch an (audio) signal (I/O (Y0, Z0) on pins 1 and 2, enable E0 on 13, 6v on 14 and GND on 7). E0 is tied with a 10K pull down resistor to GND so that bringing E0 high will allow Y0, Z0 current.

3] Transistor regulating voltage:

2N3904. CBE viewed upright from back (non-flat).

CV is by way of 10K resistor to base, emitter to output and by way of 4.7K incoming signal.

4] Further brood/cat/purrr meanderings:

a) Latest darcs pull doesn't seem to work, complains of unbound variable for -e purrr and some other problem for emacs cat.el which in principle seems to work well with older version. M-x cat after eval-buffer.

b) Following new steps with previous brood pull (pre-piksel):

(18f sheepsint) restore (after downloading: http://goto10.org/~tom/18f/sheepsint-20060914.tar.gz )

then connect-default...:

error: (not-found connect-default)

still no ping...

c) Troubleshooting serial connection. Incoming serial (black RX on pin 10) seems fine. Outgoing from pin 9 of PIC18F1220 not. Tested with different PICs, MAX3232 still nothing. Sometimed random characters (numbers) from a ping.

FPGA bitstream to Flash to start on power-up: 11:12 (2006.10.31:1 fpga#22 tech_notes#300 research#102)

In theory:

1] export XILINX=~/Xilinx // where we have our Xilinx distribution

2] ~/Xilinx/bin/lin/promgen -u 0 ~/piksel/fpga_src/tutorail2/tutorial.bit -p exo -s 2048 // make EXO file fro our VGA project

3] xsload -b xsa-50 -flash ~/piksel/fpga_src/tutorail2/tutorial.exo // downloads to the board

to test the last step:...

[ see further: http://www.xess.com/manuals/xstools-v4_0.pdf ]