IK5PWC Web space
Visita il sito in Italiano Italian

CI-V based remote antenna switch

Conections (rear panel)

Let's examine the rear panel with all required connections

Rear panel

On the left side, there is the pwer supply connector as well as the power on switch: as said earler, I used an external power supply since the unit can accept a wide range of voltages and generate appropriate voltages to drive external relays. Positive terminal is the central one (as in most devices) but the internal power supply employs a rectifier to manage polarity reverse.

The little switch between the power supply and the DB9 connector should be used when performing firmware updates using the USB port on the right side: when moved on the "firmware upgrade" position, this switch disconnect the CIV from Arduino; otherwise, if CIV is connected to the Arduino, update will fail during the last step (Arduino reboot).
To upgrade the program on Arduino, simply connect the USB port, move the switch on the proper position and perform the upgrade using Arduino software from PC. When done, move the switch back to restart normal operation.
P.S.: I printed the firmware upgrade label too far from the switch, but I really don't have time (and need) to print again the panel!

The DB9 connector is used to control the remote unit: pin layout is quite simple since it uses only pins 1,3 and 5 (BCD bit 1, 2 and 3) while all other pins are grounded.

On the upper right side there are two CIV inputs which are connected together: one should be used as input from radio and the other one can be used as an output towards the computer.
The device can operate in two different modes:

Finally, the Icom ACC2 connector is used to get the 12Vcc from radio as well as PTT signal (if you don't need opto-isolation but you leave this module in place, you'll need to supply 12Vcc because otherwise the optoisolator won't work - as said eaarlier, you can simple put the CIV signal directly into Arduino PIN0). I went for a 4 pin miniDIN connector because it was the only one I found that can be soldered on PCB.
Pin layout I've used:

Front Panel

Let's have a look at the front panel

Front Panel

Let's start with the bigger part, i.e. the LCD module used to show all informations about the device:

A quick note regarding both MSG key and led: the latter reports to the operator that there are messages about the device status that can be shown pressing the MSG key (to hide the message, press again the MSG key or simply wait some seconds). There are 5 different messages available:

System usage should be quite simple: thour the frequency information from CIV data, the box decodes the ham band and switches the antenna based on configuration stored within the device. Automatic switching doesn't occur when:

Manual mode is enabled by simply pressing UP or DWN button (antenna is switched to next or previous one) and is disabled by pressing the ESC key. When in manual mode, the MSG led blinks to remmeber operator that switching won't automatically occur when changing band. When going back to auto mode, antenna is switched to the configured one for the band you're on.

<<< Block Diagram <<< >>> Configuration >>>
© IK5PWC Luca