This simple key is assembled with a PIC16F628A. Internal
controller's generator on 4-MHz provides function of the PIC.
The key can work at feeding voltage from 2 to 5.5-V. Some samples
of the PIC16F628A may work when feeding voltage drop ever to 1.2-V.
Consumption current at working mode is 2- 4-mA (at supply voltage
5-V) and 0.5- 0.8-mA (at supply voltage 3-V). Consumption current
at sleeping mode is less the 1-μA.
So, the key can be fed from a small Lithium battery
which may be fed the key (ever without a Power Switch) for several
Iambic mode with memory of last item of data
Iambic manipulator may be reversed with help of buttons
4 memory cells, each one has capacity of 30 letters
Memory cell can be written by PIC's key. Rewriting
resource is 1,000.000 times.
Needed corrections in the entering data may be made
during the record
Data in the memory cell keep saved without power supply
across the PIC
Keying speed could be adjusted (with help of a variable
resistor) from 4-WPM up to 100-WPM.
can turn ON/OFF with buttons
Simple hand key may be switched on
Ratio "dot- gap- dash" may be chosen with
a multipoint switch:
● Record to a memory cell
Hold button of needed memory cell for 2 seconds. Speaker
transmits "WR"- it means that key stands for the record.
At a record the gap between letters the key recognizes automatically.
For installation a gap between words you need to do pause in the
record for 2 seconds. Speaker transmits "R"- it means
that the key is "understood" the gap between words and
key is waiting for the record of next data. So, before enter of
new data you may drink a coffee or read a book. Key will wait
you for the record. When only 3 letters are to finish the memory
cell the Sidetone is changed in frequency.
To terminate the record tap any button.
● Correction of Data
If an erroneous symbol was entered do transmitting
dots in number more than six. Speaker will transmit "R"-
it means that key stands in "Correction Mode." After
that speaker transmit "Last"+"last right letter"
and go to Waiting Mode. Speaker transmits "Last NO"
if an error was on the first record letter.
the Key by DL3MIH