Questions tagged [serial-communication]

Process of sending data one bit at a time, sequentially, over a communication channel or computer bus. Most of the computer systems, and especially embedded systems, have such communication port.

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Reverse engineering an hydrometer's Bluetooth communication

This is a very specific question. I'm currently working on a project to create an android application capable of reading the values of an hydrometer via Bluetooth. By reading the datasheet, I suspect ...
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341 views

Trouble finding the right Checksum algorithm

After reading a lot of posts here and their solutions, Punching lines in CRC calculators for several days now. I can't seem to find on which Checksum this code is based. Background This is a data ...
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Reverse Engineering XORed string

I am trying to reverse engineer some data received over serial port. The hardware sending the data consists of a gps, compass and a power monitoring unit (which sends information about the battery). ...
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1answer
134 views

What is an "mpi register base"?

For the past few months, I have been using my spare time reverse engineering a set top box that will not be named. I am trying to run a media server or use it as a debian desktop. It is rocking a ...
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Reverse engineering unknown RS232/UART binary protocol

Background story For couple of days I'm trying to crack the protocol used the old medical device, in order to collect data for a research in an automated way. The device in question is Novametrix ...
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124 views

CRC with OR but seed differ every time the protocol restart

It's some days I'm trying to understand how this protocol works without any success. I need some help. Basically I'm sniffing an UART signal. 115200 8N1 I understood what's happening under the hood ...
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LIN bus frame replacement

I am searching for a way to replace certain frames on a LIN bus network. My aim is to be able to intercept a frame in transmission, and change certain bits. Naturally, that involves recalculating the ...
2
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1answer
349 views

Help determining pinout for communications port

I have a Panasonic air conditioner that has a header on the mainboard that various optional (expensive) addon communications modules can connect into eg wifi The unit is a Panasonic Split system from ...
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137 views

serial protocol patterns

I am reversing a serial 232 protocol and I found these pattern in the data. E5 A7 CD 01 00 79 .. .. 40 00 23 00 23 00 23 00 23 00 22 00 22 00 22 00 21 follows some recording and expected approx ...
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Dump router firmware over U-BOOT

I connected ttl cable to my router board, and Im trying to dump firmware in order to flash second device over web interface with my backup so I have few questions: What binary file for ex. upgrade....
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280 views

Puzzling 16bit checksum/CRC reverse engineering problem

We're having a hard time figuring out how the checksum/CRC is calculated for this serial communication protocol we're required to reverse engineer. This is a communication protocol used back in the ...
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690 views

Flashing NVRAM with U-Boot 1.2.0

I tried to program SPI Flash NVRAM (S25FL064A) from U-boot, but it not allow to write: tftp 0x80000100 nvram.bin cp.b 0x80000100 0x007b0000 0x00050000 There is no error shown after cp.b command, ...
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Launching Linux kernel on UART serial interface, but can't login because key-mappings change randomly

I am trying to root an old Linux device I have, it uses the CFE bootloader by Broadcom. I know the username and the password, but something really strange happens when I try to login. I get a prompt ...
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Tapping into Ford SCP BUS

I'm looking to tap into the Ford SCP BUS to display text onto my dashboard on my '01 Jaguar S-Type. This car has a two row screen that displays the odometer, average fuel consumption - amongst other ...
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165 views

What is this RS-485 communication protocol/

I am trying to reverse engineer a two wire RS-485 standard serial bus interface to talk to a samsung heat pump. Here are some hex commands I was able to sniff. Every message starts with 0x32 and ...
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How to make sense of this one pin serial communication

I am trying to reverse engineer a serial communication between to microcontrollers (1 device & 1 microcontroller on a board). One MCU validates the other MCU and I want to crack the validation and ...
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750 views

ZyXEL P-2812HNU-F1, replacing the U-Boot on the board

I want flash regular(non branded) firmware on ZyXEL P-2812HNU-F1 router, which have branded version of firmware (customized for local MSO provider). To do this, I should first replace the U-Boot image ...
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Reversing a serial communication with two inputs

I'm making a device that needs me to transfer some sort of initiation code like handshaking to start further communications. There is 2 inputs and 2 outputs the first output is pretty similar to a two'...
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166 views

Trying to replicate a serial protocol

Spent the last few weeks reading, typing, testing, rinse & repeat to no avail in solving a problem. Problem: Trying to reverse engineer a serial protocol at work. Instrument is currently being ...
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338 views

How can I figure out what serial port communication protocol is a software using?

I'm working to adapt an stress excercise test software so that it can work with a treadmill that uses a different communication protocol. The communicate via a RS232 cable, with a USB-RS232 adapting ...
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Serial console stops output abruptly

I've been playing with a device similar to this one: EPC3208G. I've connected GND, TX and what i think is an RX pins via ttl adapter. Using minicom, 8N1 and baudrate of 115200, I managed to get some ...
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UART RX not accepting input

I am currently trying to gain access to an Epson PX700W printer that exposes UART. It has been shown, that the UART exposes a root shell. For Epson Artisan 700 this UART is fully functional: https://...
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1answer
34 views

The Logic Of Incremental Data on Serial Communication Encoding

These are the serial communication reverse values. I am trying to understand the logic behind this. I am pretty sure that 2 bytes represent 1 byte(high byte and low byte), values are correct. I tried ...
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Checksum of an old serial devices

I've got an old devices which communicate through serial port. There's main device which send simple commands and then asked device responds. I've got almost all sorted out. The only thing left is the ...
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85 views

Reverse engineer 8 bit check sequence for old unkown protocol

I am using an old piece of hardware which uses an RS485 serial interface. I'm trying to simulate slave node data but I don't have any documentation on the protocol and unfortunately the hardware is ...