This iambic keyer uses a PIC16C84 or PIC16F84 microcontroller to generate
the dot/dash timing and key the transmitter. Most modern rigs
are keyed by grounding the key line. The maximum current on the
keying line is usually no more than a few mA. If your transmitter
has high voltage or high current on the keying line, you will
need to use a relay to key the rig (see circuit below.)
You can download the pic program source code here: iambic.asm
PIC16F627 and PIC16F628 code here: iambic-62x.zip See below.
KEYER COMPONENT OVERLAY (VIEW FROM COMPONENT SIDE)
USING A RELAY TO KEY THE TRANSMITTER
Sept 2009. The circuit was modified to work with the PIC16F627 and PIC16F628. Note that the PIC16C84 RC oscillator
has been replaced by the ER (external resistor) oscillator configuration of the PIC16F62x. The hardware
modifications are shown below. Source code and HEX files are available above. This configuration has been tested
with the PIC16F627 and PIC16F628. The chips I used were -04/P types (4MHz/DIP). It will almost certainly work
with other 62x variants like the PIC16F628A.