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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15
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2answers
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Determining the serial port protocol of a typewriter

How can i determine the serial protocol of a electric typewriter? some electric typewriters have a serial port in the back and it is a shape that is not commonly used today. I am planing on ...
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7answers
11k views

How to see what data is being transmitted when an application calls home?

Always wondered how it would be possible to see what data is being transmitted back and forth with an application that calls home. Let's say we emulate the server via host file redirect. Would it be ...
9
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1answer
3k views

RS-485 Checksum Reverse Engineering (Watlow EZ-Zone PM)

I am trying to reverse engineer a two wire RS-485 standard serial bus interface to talk to a Watlow EZ-Zone PM of which I have not been able to find any documentation of the protocol. I have managed ...
9
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2answers
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Reverse engineer Logitech Z906 serial console: getting started

I would like to control my logitech Z906 remotely, e.g. with a webservice running on a raspberry pi connected to it's console. The console is connected over a DB-15 port to the subwoofer. I called ...
7
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2answers
2k views

Determining RS232 bus settings

I have a device with two chips without part numbers. It looks like their using RS232 for serial communication (proper setup, right voltage), but I do not know the bus settings (speed, parity, etc.). ...
7
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2answers
1k views

Router's serial port only outputs garbage

I'm trying to reverse engineer a 2Wire ADSL modem/router, mainly for practice. I opened it and found a serial port (with a header conveniently already in place) but I'm not getting any useful data out ...
6
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2answers
525 views

I really struggled to figure it out, now can anyone help me reverse engineer this checksum?

I have a device at work with no documentation about it's checksum calculation. I know that the last byte in each message is the checksum, and most of the messages to the device requires a correct ...
6
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3answers
4k views

Reverse engineering USB peripheral driver

I'm looking to reverse engineer a Windows driver for a printer I have here. I found out a bit about USB sniffing but I don't think Snoopy runs on Windows 7. I know the driver is on my computer ...
6
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1answer
1k views

Identifying a toner chip and it's communication protocol to re-program it

I need help identifying a chip and how to reset it from a new brother toner cartridge TN227 and TN223. This comes from the new Brother HL-L3230CDW laser printer. There is currently no information on ...
5
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2answers
509 views

Thought I found serial port - broke embedded device instead! Help?

Well another weekend has gone by and my tinkering has caused another device to (potentially) bite the dust. I've been playing around with a couple of Slingboxes, an M1 and a 500. Today was the M1. I ...
5
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1answer
1k views

Decoding serial data

I have an energy monitory and I managed to get into the feed. I got the handshake packets sorted but I am stuck on working out how to decode this data from HEX. All I know are the following values as ...
5
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2answers
2k views

Determining CRC algorithm (16 bit?) over RS-232

I give up.... I've tried for two years to determine which CRC algorithm is being using over an RS-232 serial connection between two pieces of equipment. The equipment dates from about 2002. I'm only ...
5
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1answer
768 views

Need help with a USB gaming mouse

I have a Chinese USB gaming mouse (04d9:a070) which has 4 color modes and 4 light levels. I know for a fact that this mouse is capable for showing at least 5 different color so it must be an RGB led (...
5
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1answer
1k views

How to identify SWD (Serial Wire Debug) pinout?

When trying to access firmware, JTAG and SWD can be really helpful to the reverse engineer. When looking at an unknown board/device tools such as JTAGEnum or JTAGulator are really helpful in ...
5
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0answers
602 views

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 ...
4
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1answer
1k views

Finding out checksum algorithm

I have old serial communication protocol and having some trouble finding out about checksum algorithm that has been used. I've tried several CRC16 algorithms and none of them seem to work. Tx message ...
4
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2answers
1k views

Decoding the wire protocol (over RS232) for custom hardware <-> windows application?

Background I have a hardware device with an RS232 port, and a Windows (XP) application that it talks to. No OS-level drivers beyond basic serial, so all the decoding is done in the app. I have the ...
4
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2answers
297 views

Anti-theft system rs485 keypad

I'm trying to recycle an Anti-theft system keypad. My goal is use this keypad as my system peripheral. This keypad is interfaced with its master device phisically using bus rs485. The first step in ...
4
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0answers
330 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 ...
4
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0answers
803 views

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). ...
3
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2answers
185 views

Reverse engineering the IBM BSC (Bisync) protocol

I am trying to connect to an old piece of communication controller which use the IBM BSC synchronous protocol but I have problems to get the CRC right. Background The protocol itself is described ...
3
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1answer
715 views

Reverse engineering serial communication CRC algorithm

I'm working on reverse engineering the serial communication protocol of an obsolete electronic control system, but I'm having trouble figuring out the CRC algorithm and polynomial. I have reverse ...
3
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1answer
1k views

Sniffing serial Bluetooth traffic on Android

Related to UE Megaboom serial protocol: I am trying to get some insights on the serial protocol spoken by the UE Megaboom, which I suspect is how the app controls the advanced features of the speaker. ...
3
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1answer
244 views

Decipher variable length serial protocol

I have an ebike consisting of a controller which regulates power to the motor and a smart LCD which can adjust max speed, power output, pedal assist sensitivity etc as well as displaying the current ...
3
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2answers
118 views

Finding code in MFC32 binary

I am trying to figure out where the code is that interacts with the Serial Port on an MFC Win32 binary - and am utterly out of ideas on how to find this code block. I have even tried, say, stopping ...
3
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3answers
1k views

Decoding proprietary 485 comms

I am trying to decode a reverse cycle split system air-conditioner comms signal so that I can control an outdoor a/c compressor unit without using the manufactures indoor unit. The unit is made by ...
3
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1answer
355 views

What is contained in this transmission? (RF pool-temperature sensor base unit receiver)

Note: I've made progress over at the EE stackexchange on pulling bits out of the signal (see https://electronics.stackexchange.com/questions/145714/what-encoding-is-used-in-this-signal), but now i ...
3
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1answer
935 views

Reversing serial RS485 half duplex bus protocol understanding

I have a master & slaves setup in which the slaves only respond when spoken too. I can snoop & record an existing master/slaves conversation. I have an extra slave device that I would like ...
3
votes
1answer
110 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 ...
3
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0answers
1k views

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 ...
3
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0answers
123 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 ...
2
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3answers
163 views

Reverse Engineering RS232 protocol misterious last byte

I have an old water purifier system that consists of a PDA and a main board (I think the ic is a Renesas) that communicate by RS232, I need to know the protocol they use to communicate in order to ...
2
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2answers
679 views

Reverse engineer DB25 protocol

I have a device that consists of a machine and a control head, connected with a cable with Dab25 connectors at both ends. The control head contains various buttons and dials for operating the dip ...
2
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1answer
95 views

Reverse engineering 12-byte serial packets from doorbell

I'm trying to reverse engineer the protocol used by a fairly old video intercom. Using a UART logic analyser was able to guess the baud rate, data bits, start/stop bit. It idles at 14v and pulls to ...
2
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1answer
214 views

UE Megaboom serial protocol

I recently got a UE Megaboom Bluetooth speaker. Apart from various audio profiles, I noticed the speaker also exposes a Serial Port BT profile. I suspect this is the channel the app uses to control ...
2
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2answers
155 views

Figuring out how an old serial based PC IR remote control works

I have an old serial based remote control for the PC. It has an IR receiver that plugs into a standard DB9 serial port. I am trying to figure out how this remote works. I have downloaded various ...
2
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1answer
185 views

Help locating Serial Port on embedded device

I've been slowly working on getting into the workings of a set-top box. I hit a snag when the firmware that it downloads is encrypted. I managed to find some pictures of the circuit board (but haven't ...
2
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1answer
328 views

Mechanisms to stop serial console accepting input on a Linux system?

I am working on a simple embedded system based around an Olinuxino board. This has a serial console header onboard. TX and RX are both connected to the respective pins on the microcontroller (i.e. ...
2
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1answer
228 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 ...
2
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0answers
136 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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0answers
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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....
2
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0answers
279 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 ...
2
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0answers
671 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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1answer
197 views

Hex timestamp decode

I am trying to decode this hex timestamp: 5A24 B103 73AE --> 02/26/2018 15:45:44 5A24 FC03 83BC --> 02/26/2018 17:00:48 5A24 FE03 93E3 --> 02/26/2018 17:02:58 Data is coming from an old ...
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1answer
44 views

Wrong keyboard strokes sent to serial in putty

I am attempting to communicate to a device i have via the onboard rx/tx solder points i found on the board. I am doing this via an arduino uno. The problem i am having is that when i connect to it ...
1
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1answer
852 views

Help decoding this UART serial signal

I'm trying to break into a doorbell. It has a clearly labeled TX pin. Here's the output from my Labrador oscilloscope/logic analyzer.. I can't get it to make any sense though. Any ideas? I have the ...
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1answer
1k views

2byte checksum for serial traffic

I'm working on an RFID reader that has partial implementation with ISO/IEC 14443-4 although not specifically compliant. I can decode a lot of the strings and understand the command base but I have not ...
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1answer
974 views

Finding JTAG/UART Connections

I need help identifying the UART or JTAG connections on this board. I would like to dump the firmware using a pirate bus.
1
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1answer
260 views

Understanding decoding communications over interfaces

I'm currently in the middle of trying to decode the communication of an hydrometer. Thanks to a previous question made in this site I was able to find a PDF describing the communication of a different ...
1
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1answer
36 views

Is it possible to see the traffic on Virtual COM Port to reverse engineer how a device works?

I have a USB device that when connected into the computer ends up showing up as 4 Virtual COM ports in the device manager. As far as I know, two of these are never used. One of them is seldom used and ...