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Ritron DTX-142 Hardware Hacking [message #3235] Tue, 13 December 2016 03:42 Go to next message
kc2nda is currently offline  kc2nda
Messages: 42
Registered: December 2004
Location: New Paltz
Member
This radio is a very nice radio designed by Ritron. The model is a DTX-142.

This first thing I like to do is to look at the processor. Of course it is an Atmega8.

Ritron EEprom Atmega8

I pulled out the Bus Pirate and read the eeprom and flash.
I have successfully read the eeprom with a Raspberry Pi as well. I will post another thread showing exactly how to do this.

Ritron Eeprom Reading Hacking

Here is the Hex Data Dump of the Atmega8 eeprom and what I have discovered so far:

Ritron Radio Hex Dump

The Ritron eeprom can be written to using an eprom programmer. Changing the frequency is very easy to do using the 6 pin Serial Peripheral Interface (SPI) bus which is a synchronous serial communication interface specification used for short distance communications. Serial Clock:
SCLK : SCK, CLK.

Master Output -> Slave Input:
MOSI : SIMO, SDI,[2] DI, DIN, SI, MTST.

Master Input <- Slave Output:
MISO : SOMI, SDO,[2] DO, DOUT, SO, MRSR.

Slave Select:
SS : nCS, CS, CSB, CSN, EN, nSS, STE, SYNC, SSQ.

The Ritron's receive shield was removed to reveal the Receiver Synthesizer chip. The microprocessor connects to the LMX2316 which tells the radio what RX frequency to tune to. It loads the synthesizer via serial communications.

Ritron Radio Receiver

We can see that the mechanical potentiometers can and will be replaced with digital potentiometers.



[Updated on: Sat, 25 February 2017 12:22]

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Ritron DTX-142 Reverse Engineering EEPROM Data [message #3240 is a reply to message #3235] Sat, 31 December 2016 02:53 Go to previous messageGo to next message
kc2nda is currently offline  kc2nda
Messages: 42
Registered: December 2004
Location: New Paltz
Member
The left dump is the EEPROM from the Ritron. The right is the saved file from the Ritron software. You can see clearly that there are 255 bytes that are exactly the same. They literally write exactly what is in the EEPROM to a file and pad the first 48 bytes with the radio type, etc...

Ritron Reverse Engineering
Ritron DTX-142 S-Meter Add on [message #3247 is a reply to message #3240] Sun, 23 April 2017 23:10 Go to previous message
root is currently offline  root
Messages: 207
Registered: December 2004
Senior Member
Here is the OLED added to the Ritron. The OLED is controlled by an Arduino and the RSSI was taken from the Ritron and fed into the Analog to Digital pin on the Arduino.

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