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Micro-controller-based T/R Sequencer: Request for Beta Tester



Hello everyone,

A couple of months ago I posted a message regarding a
micro-controller-based radio T/R Sequencer that I was
designing. Well, now I am finished. I have submitted
an article for publishing in a major ham radio
magazine. 

In the meantime, I am looking for a beta tester
(someone willing to test the device and provide
feedback). That individual will be required to test
the unit with real amateur radio gear and while having
QSO's. To that tester, I will provide a unpopulated,
etched PCB and a programmed PIC controller for free.
The tester will purchase the remaining components from
Digikey (~ $50 US) and assemble the board. 

In order to better describe the sequencer, here are
some of its features:

- It is a micro-controller-based approach, which
brings a lot of features and flexibility into the
unit.
- The Sequencer controls up to six outputs; they can
be individually configured as either normally open,
normally closed or they can be disabled.
- All outputs are switched through solid-state relays;
no mechanical relays are used. Currents up to 2.5
Amperes can be handled, depending on the solid-state
relays populated.
- The outputs can switch AC or DC loads of up to 30V.
- Switching detection is fed back to the
microcontroller for confirmation purpose. A timeout
feature will abort the sequence if switching feedback
on an output is not detected within a predefined
delay.
- The Push-To-Talk (PTT) logic can be configured for
either current-triggered or open-triggered.
- User-set delays are inserted between any two output
state changes. Delays are set for both the RX-to-Tx
and the Tx-to-Rx sequences independently.
- While under operation, all Sequencer connections to
the radio equipment are isolated from the
micro-controller side, thanks to extensive
opto-coupler usage. 
- The Sequencer provides a visual indication of each
outputís state via a series of bi-color LEDís.
- It also emits various tones via a piezo sounding
device at switch completion, for feedback alarming and
as a transmit timeout alarm (more on these below).
- A hardware watchdog ensures that the outputs get
promptly released if the firmware is ever to crash.
- All the electronics are contained on a small
double-sided PCB.
- A Windows-based software tool allows to configure
the Sequencer in a matter of minutes via a RS-232
link. After configuration, the personal computer (PC)
is disconnected. All settings are saved in
non-volatile Flash memory.

So if you feel you would like to help, please send me
an email at ve2zaz@amsat.org.

Just a closing comment, this is for amateur radio, not
for commercial applications. I do this for fun, not as
a business.

Thanks!

Bert, VE2ZAZ
Amsat #27668
ve2zaz@amsat.org
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