Short description of a homebrew "QRP keyer" with a PIC microcontroller
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This project describes the construction of a real "QRP" keyer
with a small microcontroller (PIC 16F84 or 16F628). This keyer features : 
- variable CW speed, adjustable via poti from 20 to 300 letters per minute
- two message-memories (50..64 letters), each controlled by a pushbutton
- command mode only required for setup and more complex features
- special modes like "endless" calling loop
   and automatic contest number generation
- very low power consumption: 50 microampere at 2.4 V supply when active,
   less than 1 microampere in standby mode (which is enterd automatically)
- simple circuit, can be built on PCB with less than "half matchbox size"
- dash/dot-memory can be turned on and off
   (I guess that's "Iambic mode A" and "B")
- Controller is clocked by a built-in RC-oscillator
   with only 50kHz clock frequency
- passive piezo speaker can be connected as sidetone

There are only minor differences between the old PIC16F84 and new PIC16F628
variant, but if you have the choice, use the second. The 16F628 is cheaper
than the 16F84 but better (more FLASH, more RAM). Be careful, the oscillator
sections of these two PICs are different, all other pins are compatible.
The 16F628 variant now uses an INTERNAL RC-OSCILLATOR so you don't need
the 3.3 MOhm-resistor which was mentioned in an old circuit diagram.

 
More about this Keyer can be found in:

  QRPKEY_H.ZIP = HEX-file you need for programming the PIC processor
  QRPKEY_D.TXT = deutsche Bedienungsanleitung und Beschreibung
  QRPKEY_E.TXT = english manual and description
  QRPKEY_C.GIF = circuit diagram of the QRP PIC keyer
  QRPKEY_P.GIF = etching pattern for a very small PCB (2.6cm*3.7 cm)
  KEYER1A.ZIP  = assembler sourcecodes for both 16F84 and 16F628 (your choice) 


The ZIP and GIF files may be "seven plus"-coded for the packet radio system.
It will take an ugly lot of time to upload these files, so please be patient.

   And please don't ask me to send you programmed PICs or PCBs.
Sorry, but I can NOT. You can find many simple PIC programmers everywhere,
for example on this web site:
   http://come.to.thepicarchive
  (a mirror site of Dave Tait's ex-PIC-homepage
   with a lot of PIC-related goodies)
Alternatively you may try DL4YHF's simple PIC programmer for windoze,
somewhere available at the DL4YHF homepage.

Fuer die Leser des deutschen Funkamateurs: Im FA Mai '98 stand mal ein
recht simpler PIC-Programmierer. Die dort genannte Adresse der Firma
Silicon Studio wo man die Programmiersoftware beziehen kann stimmt
nicht mehr, neue Quelle siehe oben. Oder Sie verwenden DL4YHF's simplen
PIC-Programmer fuer Windows, gibt's irgendwo auf der Homepage.

If your packet radio connection is as slow as mine, you may download this
(and some more construction details) on the internet:
  www.qsl.net/dl4yhf/keyer1.htm.

Good luck and have fun with this project. Life is long enough for QRP.
73's from DL4YHF (Wolfgang).
