73 Amateur Radio Today - Free and Open Source Software

in raw code and the loops and branches can
make following the program flow difficult.
The use of in-line code is not "efficient" as
far as memory space is concerned, but it is
good for de bug efficiency and it is better to
have good fat code than compact buggy
code. Once the code is debugged, then it
can be "optimized." Also, in-li ne code gcnerally
runs faste r and is much easier to fotlow
if it has to be modified at a later time
by a third party.
The last item is a lesson that I seem to
have to learn every time I do a program.
Change only one thing at a time! It is
tempting to change several things at once
before doing another download or PROMblast,
but if you do it this way it can be
hard 10 see just which change caused
which bug.
Using the Cont roller Board
Connections are made to the
Kendraboard as follows:
Machine Code Listing (Modified .519 File)
5 113 1000 40060000000000000066A31001000000 7C
5 113 101 0 0066D762A3290400 00680A4D6EF131 6B A3
510B 1020 00673ED32E6BBF61 93
511 3 0100 A6FFB704A6FFB700A600B705A6 FFB706 68
5 113 0110 A67FB702A600B78087B1B7B28783B7B4 4A
5 113 0120 B78587B6B7B7AEOOA67FCD0209A6BFCD A7
5 113 0130 0209A60FC00209A6EFCD0209A6F7CD02 7A
5113 0140 09A6FBC00209A6FOC00209A6FECD0209 32
5113 0150 3FA83FA93FAA3FAB3FACAEOOCD01D1 AE 13
5113 0160 01C001D1AE02C0 0101 AE03C001D1AE04 9A
5 113 0170 COO l 01 AE05CD01D1 AE06CD01D1AE07CD B5
5 113 0180 0101 B6A8C00100B6A9CD01 D086AAC001 58
51 13 0190 00B6ABC001 0 0 1A02CD01FF1E02CD01FF 9C
5 113 01AO 1F02CDOl FFCC01 2698B79FB6ACD91020 11
5 11 3 0180 B7ACB6ABD91018B7ABB6AAD9101OB7AA 5A
5 113 01CO B6A9D9100887A9B6A8 D91000B7Aa869F 80
5 113 0100 a1 E6B02707CD01A84ACC010381BF9EAE EA
51 13 01 EO OaCD01EA5A26FABE9E8 14824051B02CC 9A
51 13 01FO 01F41A029D9D9D1 0 0290 90 901 C0281B7 C7
51 13 0200 9FA6104A26FD869F81B700CDO 1FF8601 17
5 10A 0210 43A40FE7B05C81 79
5 105 1FFE 0100 DC
59030000FC
Pin MPU Port Signal
P6·1 PA7 x10MHz COM
P6-2
P6·3
PA'
PAS
x1M Hz COM
x100KHzCOM
P6-4 PA' x10KHz COM
P6-5
P6-6
P6-7
PA'
PA'
PA1
x1 KHz COM
xl00Hz COM
xl 0Hz COM
T-R adapter/amp board and updated software
will allow me to use this combo in
a nd is about the size of a large postage
stamp.
P6-S
P5-1
P5-2
P5-3
P5-4
P3-1
P3-3
P3,4
P3-5
PAO
PBO
PB1
PB'
PB'
GNO
PC7
PC,
PCS
x1Hz COM
BCD "1" line
BCD "2" line
BCD "4' line
BCD -a-uoe
Jcueocero ground
Jcneooaro * XFER (P1-7)
Julieboard SCLK (P1-6)
Julieboard SDATA (Pl -2)
VFO service for my Atlas 2 10 transceiver.)
My favorite use for the stand-alone combo
is as the LO for a tunable mixer. I have
a Mini-Circuits SRA- I mixer in a BNCequipped
box: The RF port goes to the antenna,
the LO port goes to the Julieboard,
and the IF port goes to a surplus crystalcontrolled
SSB/AM receiver tuned to 6.300
What's Next?
I plan to evolve my design as I go, and
add (in rough order):
-Extemul BCD display via ' 595 shift
registers.
-Opdon for up/down non-mechanical
MHz. I program the Julicboard to produce tuning.
The connections on P3 can be made an output 6.300 MHz above/below the de­ -SCI support (remote operation via serial
directly to the Julieboard via a cable or sired freque ncy, set the proper sideband. port).
via wire-wrapped j umpers bridging P3 and .. . voila! Someday, I will mod the -EEPROM support.
10 the DB25 connector (PI). Note that software so I won't have 10 do the frequen­ -Offscts for usc as transceiver VFO.
the physical wiring differs for male vs .
fe ma le DB25-examine the chosen
cy offset in my head.
Of course, this controller is suitable for Conclusions
connector carefully and locate the rig ht controlling things other than just I have had the stand-alone controller
pi ns. (The ground connection need not Julicboards. For example. one of the newer running the Jul ieboard DDS synthesizer in
be made if a DB25 of either sex is -.:..:.:..:.:..:-----....:-.:..:--------- my shack fo r severa l weeks and
used.)
The single in-line connectors are
cnd-stackable, so some con nectors
could be partitioned into two smaller
connectors . For example, "P6" could
"Not having to wait/or boot-up
is great and there is a
noticeably lower RF noise level
am very happy with it I can't wai t
to incorporate it in my portable
Q RP transceiver project. Right
now, I have the bes t of both
worlds- if I need special programbe
implemented with a 4-pin connector
to bring in the 4-bits BCD from vs. the pc."
ming functions, the Julie board can
be unhooked and reconnected to
t he sw itch matrix and a a -pin the PC ; othe rwise, it is left atconnector
to bring out the spare two tachcd to the Kcndraboard for gcn-
Pori B b its and ground . T his a llows high resolution O/A converters could be era! purpose operation. Not having to wait
a more modu lar system w here the driven to make a digital power supply or for boot-up is great and there is a noticethumbwheel
switch cabling is completely voltage source. How about -1 6.384 V to ably lower RF noise level vs. the PC.
separate from the cabling to those two
spare bits. Likewise, connectors P2 and P3
+1 6.383V adjustable in I mV steps via
thumbwheel? Or one of the new PLL chips Personal Note
may be partitioned into subsets.
and thurnbwhcels for a synthesized 6m or W hy "Kendraboard"? Reade rs fami lia r
Note that Julieboard signals ENPHACC, 2m rig?
with the "Julieboard" article will recall
SHIFfEN, and BANKSEL are not present­ There is no reason why the processor has that J ulie had two (now th ree!) siste rs
ly used. but could be in future versions. to be a '6805 (or even a Motorola device). and that they expected equal treatment.
One ad vantage of using the DB25 is thai an For example, PIC ch ips are available via Kendra thought that naming the controller
opposite-sex multiple OB25 "bac kplane" DigiKey. and one quite intriguing product after her was a great idea. Now Karen arrangement can be used to allow addition
of future boards to the set. (For example, a
is a " BASIC stamp" whic h runs BASIC
programs kept in an on-board EEPROM
wants to know when I'm going 10 do her
board. . . iii
20 73 Amateur Radio Today. August, 1994