The i-kaktusss. Iambic Keyer And Koch Trainer Using a Seventeen Segment Screen.

Transcription

1 The i-kaktusss Iambic Keyer And Koch Trainer Using a Seventeen Segment Screen.

2 Building the i-kaktusss An assembly manual for the i-kaktusss iambic keyer and koch trainer using a seventeen segment screen. By Erich Heinzle, VK5HSE Assembly manual version 1.2 Kits are currently available from Aztronics, Thanks to VK5TR, VK5RG, VK5PH, VK5FJ, VK5MC and Mitch at hackvana.com for helpful input on the keyer design, software and assembly manual.

3 Preliminaries Before starting, decide on whether or not you wish to use the keyer for more advanced purposes such as rig keying, rig sequencing, adding a low pass audio filter, adding AF driven on off rig keying, adding a sinewave oscillator to the prototyping area, or wiring the 3.5mm headphone jack, as this will affect the construction steps in the area allocated to the piezo sounder. Users simply wishing to build a practice keyer can proceed and follow the normal instructions.

4 Step 1 Start with R1 390ohm

5 Step 2 Add remaining R2-R17, all 390 ohm (Orange, White, Brown) 330 ohm resistors (Orange, Orange, Brown) will do the job, but give less safety margin if supply voltages are on the high side

6 Step 3 Add pullup resistors R18, R19, R20, all 4.7k (Yellow, Purple, Red) Builders wishing to experiment with touch keying will need to skip installation of the R19 and R20 pullup resistors, or install headers on the pads provided to enable them to be disabled.

7 Step 4 Add D1, observing polarity make sure the band on the diode matches the PCB silkscreen

8 Step 5 (Optional) Add D2 for the non USB power supply option, observing polarity

9 Step 6 (optional) Add D3 for the non USB power supply option, observing polarity

10 Step 7 Add R21, the reset pin pullup resistor, 10k (Brown, Black, Orange)

11 Step 8 Add R22, (10k) (Brown, Black, Orange) and R23 (22k) (Red, Red, Orange). Even if you're not planning to install a programming header to reprogram the microcontroller, R22 and R23 are nevertheless needed to keep the PicAXE28X2 happy.

12 Step 9 Insert the 28 pin socket for the picaxe28x2, with the notched end closest to the diodes Desperados can use two 14 pin sockets

13 Step 10 (optional) Install the 3.5mm stereo jack if you plan to use an external keyer v1.67 PCBs require the socket to be attached to the underside if tip/ring dit/dah wiring has to be consistent with the usual wiring convention. This has been fixed on later version PCBs, and it can be attached to the top, as shown.

14 Step 11 Add some paper, adhesive tape, or some other spacer to the underside of the crystal to stop it shorting out the PCB holes. Note: the current software will behave the same with or without the crystal installed

15 Step 12 Solder the crystal into place, ensuring it does not short out at the base.

16 Step 13 Add C1, C2, and (optional for non USB power supply) C4, all 100nf (0.1uF, usually marked as 104), for decoupling the power rails.

17 Step 14 (optional) Add the polarised electrolytic capacitor, C3, if non usb external power is planned, to decouple the power supply. Make sure the capacitor's negative stripe is towards the edge of the board, away from the silkscreen's + symbol Select the holes that are best fit for the capacitor

18 Step 15 Add S1, the menu button

19 Step 16 (optional) Add the 7805 regulator if external non USB power is planned

20 Step 17 (optional) Add the external DC socket, if external DC power is planned

21 Step 18 (optional) A trick to increase the mechanical strength of DC connectors is to thread a component lead offcut through the DC socket lead eyelets before soldering to the PCB pad, and then trim off the excess.

22 Step 19 Solder the piezo to the PCB. The PCB has been designed to accommodate a variety of piezo pin spacings Advanced builders wishing to use the proto area for something else, like a rig sequencer, a low pass audio filter, an AF driven on off keyer, a sine wave oscillator, or an external 3.5mm socket for audio out, can skip this step.

23 Step 20 Add the common anode (pin 11) display, making sure the decimal point is away from the piezo. Displays with a different common anode pin can be made to work, but you're on your own with the PCB and software modifications required.

24 Step 21 Add the Type B USB connector to allow the keyer to be powered from a USB cable

25 Step 22 Add C5 and C6, the capacitors required for the crystal to oscillate, if the crystal has been installed.

26 Step 23 (optional) Add link 1 and link 2 with offcuts of component leads. Add the PS/2 connector to allow an external keyboard to be used. The PS/2 keyboard is used for some of the keyer's modes.

27 Step 24 (optional) A 3 pin header can be added to Conn2 if an external programming adaptor is planned. Refer to the Appendix and/or PicAXE manual for details of the serial programming interface. A polarised header, as shown, is preferable to avoid mishaps with incorrectly attached cables.

28 Step 25 Apply external power to the board. Check that +5V is present at the 5V test point under the PicAXE28x2. If it isn't, check for shorts, and voltages before and after the diodes.

29 Step 26 Remove external power from the PCB Insert the PicAXE28x2, making sure the notched end is away from the piezo, and towards PCB edge with the USB connector and diode(s). Use static discharge precautions

30 Step 27 Programming the PicAXE28x2 By default, the PicAXE28x2 ships from revolution education with the serial bootloader installed and blank program slots, waiting for you to install the software via a serial cable into the EEPROM of the chip. Your keyer won't do much if the PicAXE28x2 has not been programmed

31 Step 28 First, a suitable serial cable is needed (one can be constructed following the instructions in appendix B) Those without a serial port will need a USB to serial adaptor (your mileage may vary depending on brand) Second, suitable software must be installed for your operating system ( Download from ) Axepad will work on OS X, Linux and Windows PicAXE programming Editor is the more fully featured option available for Windows Either option will work perfectly well for programming the i-kaktusss

32 Step 29 In the preferences of your chosen software, the correct serial port must be selected for the software to work with the cable, and the i-kaktusss must be powered up for it to be programmed The software for Slots 0, 1, 2, and 3 must be downloaded and installed for the keyer to function properly. Current version resides at: After connecting the programming cable to the keyer, and to the computer, the code for each of the slots can be downloaded, one after the other Progress bars will show the download proceeding, and the software will indicate if the download has not initiated properly. If at first you don't succeed, users should look at Part 1 of the exceptionally well written picaxe manuals: and the online FAQ:

33 Step 30 Apply power, and the i-kaktusss will start in the keyer mode by default Try pressing the Menu Button The keyer should start the menu system asking what mode to run If you wish to cycle to the next mode, press the menu button after the current mode is displayed a tick should be displayed and then the keyer will show the next mode available, again, press the menu button if you wish to cycle to the next mode Plug in an external keyer, To change WPM, press and hold the menu button, and then while holding the menu button down, hit dit or dah to increase or decrease the WPM or, make a keyer with paperclips and screws in the holes provided on the PCB, being careful not to short out adjacent pads. Start learning Morse!!!

34 Appendix A: A Simple Paperclip Keyer Find three paperclips, of reasonable stiffness to ensure springiness Get some 3mm or 1/8 inch machine screws and matching nuts Single paddle (swinging grounded paperclip, touching fixed L & R paddle paperclips), or Dual paddle (as shown) fixed grounded paperclip, swinging L & R paperclips

35 Appendix B: Serial Programming Cable Construction 0.1 (2.54mm) spaced, three pin Molex headers are ideal for the serial programming cable. The picture shows how the pieces come

36 Serial Cable Step 1 Use different colours for each wire Here we see Red: Tx Black: Rx, Green: Ground Strip, crimp and then solder the molex spring terminal to each wire

37 Serial Cable Step 2 Finish soldering the spring terminals to the wires

38 Serial Cable Step 3 Insert the wires into the Molex housing in the order shown, and with the sprung terminal in the same direction shown in the picture

39 Serial Cable Step 4 This shows the Molex Header with the wires inserted

40 Serial Cable Step 5 Strip the end then solder the Black wire to the central pin on the row of 5 on the DB9 You may wish to plait the three wires or heatshrink some tubing around them before soldering to the DB9 serial connector

41 Serial Cable Step 6 Strip the end then solder the Red wire to the second pin, next to the black wire, on the DB9

42 Serial Cable Step 7 Solder the third wire, Green, to the fifth pin of the DB9's row of five pins The already plaited cables are visible, which was done to keep the table from getting tangled during use

43 Serial Cable Step 8 A rear view of the completed wiring A backshell can be attached to the DB9 to protect the wiring from breakage or shorts

44 Serial Cable Step 9 A front view of the finished serial cable Again, a back shell is recommended for the DB9 to improve robustness

45 Serial Cable Step 10 If you a haven't already done so, solder the 3 pin header to the PCB, in the orientation shown You can now attach the programming cable and use the PicAXE software tools to re-program or customise the keyer.

46 Appendix C: Customisation options The proto area has been provided in case a low pass audio filter, sine wave oscillator, rig sequencer, headphone circuitry, or AF driven on off rig keyer, or optocoupled rig keyer circuit are planned instead of the piezo The PCB has provision for headers in case menu/reset buttons, 5V or 12V power connectors, audio, keyer, PS/2, paddles or touch keyers are to be mounted off board. Touch keying may be possible for keen experimenters if the paddle pullup resistors R19 and R20 are disabled and the software is modified to allow touch sensing. A programming header is best attached to CONN2, keeping the headphone jack free for audio/keying. The track under J2 needs to be cut and a header installed if an external mute switch is desired.

47 Appendix D: Software Modification The picaxe28x2 contains four software slots labelled slots 0,1,2, and 3 All 4 slots are used for the i-kaktusss functionality Software will need modification if on-off keying is desired, or if default WPM, keyer mode or QSO text is to be modified Users wishing to customise or upgrade any or all of the software slots can download the current i-kaktusss software from the link on the website and install this or your own customised version of the software via the serial programming cable header CONN2 described in Step 24, using the freely available download tools from See for PicAXE manuals and software for linux, mac and windows platforms The software is licensed under the GPLv3 license, see

48 Appendix E: Troubleshooting Q: My Piezo makes funny ticking sounds when programming the keyer with the serial cable A: That's OK, the Tx line is shared with the piezo Q: My Piezo makes funny ticking sounds all the time A: Your (cheap!) USB power supply lacks proper output filtering and the spikes are causing the ticks Q: I want to change the default WPM on powering up A: Change the slot 0 code to your preferred WPM and reprogram slot 0 Q: dit and dah are back to front for me A: Swap the wires around to your external keyer, or change the software and reprogram Q: Some of the characters don't display correctly A: look for shorts around the PicAXE or display pins Q: I reprogrammed the PicAXE in a PIC programmer, and now it won't work for the keyer A: you have overwritten the bootloader and the chip can no longer be used as a PicAXE. Either use this as a learning exercise and program your keyer in C with Microchip's MPLAB programming tools, or get a new PicAXE 28x2!

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