GPS receiver

I have been using Kenwood THD7 for many years. It is truly a wonderful piece of hardware, however it does not have a GPS receiver built-in. For this reason an external receiver has to be used.

THD7 supports GPS NMEA data at 4800bps only. In addition it has to be RS232 standard. In order to get some GPS receiver's default baud rate set to 4800bps, I had to modify its settings as follows:
$PSRF100,1,4800,8,1,0*0E

ATmega8A is used to do the job, when the receiver is switched on.



Kenwood THD7

pictures
GPS module testing with USB (3.3V to 5V USB translation)

GPS module testing with USB (3.3V to 5V USB translation)

PCB design

PCB design

PCB design

PCB design

PCB prototype testing

PCB prototype testing

PCB prototype testing

PCB prototype testing

almost ready...

almost ready...

it really works :)

it really works :)

After many years of working with Kenwood THD7, I decided to get rid of RS232 voltage converter between radio's microcontrollers and GPS and PC output. I am now using a standard 3V GPS module, which can be plugged in directly.

pictures
Kenwood THD7 inside

Kenwood THD7 inside

RS232 chip (ADM3202) is located above the keypad

RS232 chip (ADM3202) is located above the keypad

voltage converter is disabled and patched

voltage converter is disabled and patched

Hardware and software is self-made :)