cat and purrr first excursions: 20:39 (tech_notes#219)





Using PIC18F1220 (18 pins) and simple parallel port programmer as per:


(but using 5v 7815 regulated supply instead of 3v and thus 330 Ohm resistor).

(the only other programmer found is more complex/safer Tait-style design:



and Broccoli18 software (v. 0.8pre1).

With enough battery power we can ./readcfg

which tests the parallel port connection:

Device id 07 e7
Found PIC18F1220.

and ./writepic


but first how to generate monitor.hex to communicate by way of the serial port with our PIC:

1) From ~/brood/bin we can run brood -e purrr

from within which (ie. after running we type in):

(purrr seed sheepsint) use

to create:

(in Tom's words):

... a monitor for the 18f1220 chip, running an 8Mhz oscillator (internal) and uses a 19200 baud serial link to the host pc.

which is saved in ~/.brood/purrr/sheepsint

where we also have state.cat and init.cat and state.cat (equivalent)

(see also:

http://zwizwa.goto10.org/darcs/brood/doc/new.txt )

2) Use Broccoli18/writepic we burn monitor.hex (from there) onto PIC

3) Now over to the serial MAX232/3232 connection with the PIC:

RS232 link to host PC and capacitors connected for MAX as per:



(next stage working over serial port (lacking on the IBM T40 here))

but monitor should run as:

/brood -e purrr

and then dive in...