Article: Simple Keyer    choose article | e-mail | close 
Keyer ...

Today is quite easy to build our own telegrafic keyer. My construction is based on ATMEL microprocessor AT90S4323 and couple of external component. To be small I am using SMD type of components.
I have two versions of the keyer. First is very simple without any special features. It is determined to drive simple CW QRP transceiver, where no memory functions are required. The other one has all what such a bug should have.

Keyer features:
Tune Function
3:1 Weighting
Simple 1 Button User Interface + 1 programming jumper
Paddle Select - no more turning the paddles upside-down to change DIT-DAH
Low Current Consumption (~1 uA @5V in sleep mode)
Requires 8-16V DC input
Unique Speed Control a Paddles
Two memories for pre/recorded messages
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Keyer functions:
PB Q1 short tick - plays message #1
PB Q1 two short ticks - plays message #2
hold Q1 down + DIT = speed up
hold Q1 down + DAH = speed down
hold Q1 down + DIT + DAH = reverse DIT/DAH

PB Q2 hold Q2 down + short tick on Q1 = write up to 32 characters into message memory buffer #1
hold Q2 down + two short ticks on Q1 = write up to 32 characters into message memory buffer #2

Schematics...
The picture of the simple keyer in the pdf format   keyer_v1.pdf
while the picture of smart keyer you can see on   keyer_v2.pdf

PCB...
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Program and programing ...
Compiled program is in a downloadable format   keyerv1.hex
Download also program for loading it in to the chip   keyerv1.rar
For version 2. program is upon request.
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