[Elecraft] Questions on the KRC2 - part 2

[Jack Brindle]

> 9.  Are there any inputs?  Can the controller read the state of any
> lines?

Yes, in two different ways. There are three analog inputs which may be 
used to set the band information from third-party radios such as those 
from Icom and Yaesu. The voltages which set each band from these inputs 
are user-configurable, and stored in three separate voltage/band 
tables. Also, the four band outputs may be turned around into inputs, 
used for setting the band. At present, there are no general-purpose bit 
inputs, and the hardware has limited ability to support them, but again 
if needed, the few that exist could be reprogrammed at some point in 
the future...

> 10.  It looks like the wires are passed through the square hole next to
> the serial ports.  Is there any strain relief/shield ground on it?

There are two 1/8-inch holes that may not be shown on that picture for 
use with a plastic tie-wrap (provided with the kit) that may be used 
for securing cables. We looked at several ways of doing this, but all 
had the same problem, they would not withstand long-term use. The 
tie-wraps seem to be the best solution, and are easily replaceable.

> 11.  Can the unit be programmed to send things to the K2 to turn on the
> sidetone?  This is really useful in a mobile environment if the system
> could send CW messages out the speaker as to what it was going.

Anything that can be accomplished through the K2's serial port can be 
done from the KRC2. This includes most menu settings. The demo units 
have a button programmed to switch the Receive Antenna on and off, 
something that can only be accomplished in a menu. It also makes very 
effective use of the K2's test facility to announce CW messages to the 
user. Unfortunately when the K2 is in MENU mode it defers KY commands 
until it exits that mode, thus limiting the ability to tell the user 
everything that is going on. A speaker option in the KRC2 will allow 
these announcements without the need for the K2. If you are wearing 
headphones you will want to use the K2 announcement mode, however, 
since the K2's sidetone audio is piped through the normal audio channel.

> 12.  What is the interior slider switch for?  I assume to put the
> processor in program mode?

Yes. It is useful for either upgrade or normal modes. In the upgrade 
position the KRC2 communicates with the PC, while in the Normal 
position the K2 communicates either with the KRC2 or the PC. Even when 
the K2 is communicating with the PC, the KRC2 is listening in and can 
detect messages in which it needs to do something.

> 13.  How "programmable" is the processor?  (e.g. what language, what
> development tools, remotely programmable, how much memory is available,
> etc.)

Don't think of it in terms of normal programming languages. The KRC2 is 
designed to be very simple to configure and operate. Rather than have a 
standard compiled command syntax, the KRC2 does things a bit 
differently. There are about 60 different events which are generated 
within the KRC2. These range from initialization to band changes to 
frequency changes, and even include timeouts from a pair of 
user-programmable timers. Whenever one of these conditions is detected, 
the KRC2 generates a corresponding event which is then matched against 
the command table, which is provided by the user. Each entry in the 
table has an event and a command which will be carried out, including 
operands for that command. An  example of a command is making a CW 
announcement with the command being an Announce command, and the 
operand being the text you wish to announce to the user. There are 27 
different operations at present, each with variations that allow the 
KRC2 to perform many different functions.

Events may be the subject of several entries in the command table, so 
you could have the K2 QSY, change antennas and then send a CW message 
all from a single button press.

The main tool to configure the KRC2 is still in development, and it is 
expected that others will create their own versions from the 
specifications we release. Essentially mine has a list of events that 
may be generated and a separate list of operations. The user would 
select an event, then an operation that the event would trigger. Each 
operation would show the variations that are allowed, including space 
to enter text or numbers.

There are currently 64 entries allowed in the table. The limitation is 
dependent on two factors, the time needed to traverse the entire table 
as well as the space available in the Microcontroller's Flash memory. 
The unit also currently sets a limit of 128 bytes/characters for the 
operand table, which stores text, numbers or other information used by 
the commands.

The programming system will be the subject of its own manual, to be 
released after the main assembly/user manual for the unit. plans for 
the tools are still being developed, but you will be seeing some 
interesting things in the near future. Also look for the tools to be as 
system-independent as possible.

--- END OF PART 2 ---

-Jack Brindle, WA4FIB
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