Ham Radio Tiny IBM PS2 Keyboard CW Keyer Interface

The Experiment:  Ham Radio Tiny IBM PS2 Keyboard CW Keyer Interface. Build a (Ham Radio) Tiny IBM PS2 Keyboard CW Keyer Interface around an Atmel ATtiny85 micro-controller. Looking through the KX3 user manual (Data Modes) read that the KX3 supports data operation via a computer and special software. So launched the K3 & KX3 programing reference manual and found the (KY) command will send Keyboard DATA through the RS232 port, but there is a 24 character limit. Back to the KX3 user manual read that the KX3 can convert CW form the CW KEY jack or the KXPD3 paddle to FSK D & PSK D Data. Since the KX3 can decode CW, PSK31 (PSK D) and RTTY (FSK D) on the display. Decided to build a  ATtiny based Tiny IBM PS2 Keyboard CW Keyer Interface.

The challenge, the ATtiny85 only has 8-pins, 8KB ISP flash memory and pin1-4-8 are dedicated to Reset-GND-VCC. So the first thing to do, assign the available pins.







IBM PS2 Keyboard 6-pin Mini-Din:
1. Data
2. NC
3. Ground
4. Vcc +5
5. Clock (IRQ)
6. NC

1. The ATtiny85 only has 1(one) hardware interrupt: INT0. However, the  micro controller can have an interrupt attached to any pin 0-5.
2. Hardware interrupt: INT0 = D2 U1-pin 7

PS2 Function Keys:
F1, F2, F3, F4 Programmable Stored Message
F9 – Message Buffer
F9 – Exit Message buffer
F10 – clear line
Ctrl F9 Clear All stored messages (F1, F2, F3, F4)
Ctrl F10 Write a new stored message F1, F2, F3, F4 (to save press a F1, F2, F3, F4 key)
Up-Arrow increase WPM
Dwn-Arrow Decrease WPM

Libraries Used:


Parts List:

1. 1(one) ATtin85
2. 1(one) 7805
3. 1(one) TIP31
4. 1(one) LED
5. 2(two) .1uf Capacitor
6. 1(one) 10uf Electrolytic Capacitor
7. 1(one) 220 Resistor
8. 1(one) 4K7 Resistor
9. (one) IBM PS2 Keyboard