Questions tagged [reverse-engineering]

The process of taking a completed system and determining details of its design; may have legal limitations or ramifications in different jurisdictions

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313 views

Reverse engineering: Relay driver design consideration

While reverse engineering a garden twilight switch I frowned upon the fact that there is no positive feedback for the OPAMP. Rather than that I found a simple top detector D7/C5/R5 to drive the output ...
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1answer
814 views

What role is this Matched PNP Transistor and MOSFET pair playing in this circuit? [duplicate]

I'm trying to understand what exactly this power circuit is doing. The schematic below shows 5V in from USB. It is run through a fuse, and then there's some tricky PNP transistor stuff happening I can'...
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2answers
437 views

What is the name of this DC-DC converter topology?

I spotted a circuit in the wild that generates symmetric (e.g. ±8 V) analog power rails from a single +5 V supply using a single boost converter and a single 10 μH inductor. This is a very ...
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1k views

Why the extra transistors in this current mirror?

I'm trying to understand the unusual current mirror circuit below. The current controlled by R2 is mirrored to R1. The strange feature of this circuit is that Q1's collector and base aren't connected ...
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1answer
677 views

How does this blinking LED circuit work? [duplicate]

I found a circuit that has an led that is blinking in it. I was interested to see how it works so I took it apart and found that there was no capacitors in IC's in it (here is a picture): I think ...
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2k views

LCD display reverse engineering

I recently got in my hand an old phone lcd display. Display itself seems to be useful so I took apart it from the rest, and I begun to test its behaviour. Display is named SHARP LM167511 and its ...
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1answer
211 views

Need help finding the datasheet of this IC

I'm trying to find out what this IC is and appreciate any help! It is located inside an EV charging cable and its main task from plugs datasheet is: "STATIC RESISTANCE (FROM PROX. DETECTION TO ...
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3answers
608 views

Reverse engineering a power supply characteristics

I have this schematics and the following information: connect the + of the multimeter to test point A and the ...
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2answers
274 views

tamper proof embedded microprocessor

I develop commercially embedded hardware, using Microchip dsPIC or similar processors. The firmware I have is sometimes very complex and costly, and needs to be hacker and tamper proof in hardware. ...
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2answers
2k views

Monitoring serial communication and problems with my RS232 listening device

Currently I'm working on a little reverse-engineering project, where I want to understand the communication between the controlling software and a modem/DCE via serial port (RS232C). EDIT: both the ...
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1answer
162 views

How to amplify the resistivity range of a rheostat

I have a black box DC to AC inverter with a 5 kΩ linear taper pot wired to it that acts as an LED light dimmer. I have no idea how the circuitry of the black box is composed - it is encased in a ...
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3answers
490 views

“High Voltage” Logic levels why they are rare

I'm continuing to dissect and learn from this old (1974) calculator. One thing that surprised my was that the pins of the main IC have both negative and positive voltages 0 to ±28V. Having worked ...
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1answer
1k views

Swapping buttons on a GameCube controller [closed]

I have an old GameCube controller that I want to swap the buttons in. By this I mean that I want to press the x button and have the signal for the r button sent. I opened up the controller and found ...
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2k views

Where is ESP8266 TCP/IP stack defined?

I just installed Micropython on my ESP8266 and realized that TCP/IP works fine with it. This made me realize I don't know where it's defined - options that came to my head are: 1) in Micropython code, ...
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1answer
77 views

Is it feasible to use a logic analyser for debugging a proprietary dot matrix display and button panel for use with RaspberryPi

I have an internet radio which is not supporting the latest codecs. Details of the original radio: https://www.manualslib.com/products/Revo-Pico-Radiostation-2865277.html http://www.expertreviews....
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1answer
499 views

Reverse engineering target chip to be used with OpenOCD

I have a board that has JTAG pins and I want to connect OpenOCD to the board. However the CPU chip identification number is not written on the chip and I couldn't find the datasheet of the board. ...
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5answers
8k views

DSC Keybus Protocol

I'm plan to interface a atmel avr with my alarm system in home but the issue is DSC has a propriatary protocol between the keypad and the base. So has anyone messed with this before or can give me a ...
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1answer
3k views

Extracting firmware using JTAG

I've searched around and found quite a few examples of articles claiming to have extracted firmware from some device using the JTAG interface. I have read further that there is no general procedure ...
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3answers
645 views

Removing 'white sticker' on PCB

I want to reverse engineer the circuit from an insect swatter. However, there is this 'white sticker' at the back of the circuit. I am assuming this is for some kind of protection or just to hide the ...
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2answers
1k views

How are RS 485 transceivers implemented?

I would like to know how transceivers (which are used to send and receive differential signals) are implemented. AFAIK the receiver the transmitter (TX) could be something similar to an H bridge. I ...
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1answer
870 views

Reverse engineering 7 segment display

I ran into a problem with one of my hobby projects and at this point I need some help. I'm attempting to sniff the signals going into a 7 segment display and use them for a purpose. The display is a ...
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1answer
121 views

Identify this electronic component from DVD drive [closed]

I got this component from an old laptop dvd drive. It was placed within the laser assembly. Could you tell me what this component may be?
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1answer
134 views

Missing Component Pieces from a PCB [closed]

This PCB is from a old Sharp 1999 TV I have been reverse engineering lately; also sorry for any bad images. I have noticed that there are some "missing" components in the holes of: D4002, D4003, ...
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1answer
60 views

Missing Connector Pieces

There are missing connector pieces in this PCB that I was working on and I swear that there was no connector there in the first place, so I ruled out me going insane.I circled the connectors in gray. ...
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2answers
99 views

Can anyone identify the following signal?

Im currently working on trying to reverse engineer a USB puzzle board I was given. (its a ATMega168 based device with a standard FTDI USB to UART chip) and all the information you are given is you may ...
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1answer
1k views

Which glass encapsulated component is this?

I'm trying to reverse engineer this Chinese power supply and I came across this component: Here it is on the circuit board: And here's a close-up: It has a glass packaging, similar to a diode but ...
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2answers
271 views

Best materials to prevent reverse engineering of PCBA components? [duplicate]

I have an overmolded PCBA on a cable with passive components only. Some of the components are hard to identify, but I'm still concerned about the possibility of competitors trying to reverse engineer ...
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2answers
161 views

How can a manufacturer verify a circuit design? [closed]

Could anyone tell me what means (other than reversing) available to manufacturer of integrated circuits (latest Intel PC CPU's) that would allow them to verify that the actual design on die is ...
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2answers
707 views

ARM Cortex M3 firmware

First some background information. There is one product (a sensor) bought from a far eastern manufacturer, bless their white cotton socks, that uses the STM32F103V microcontroller. The firmware that ...
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1answer
537 views

Identifying this "IC”, Trying to reverse engineer a board

Part 1: the board and how it's connected I'm looking at a headphone sound amplifier that is used to help experts detect pests in palm trees when a microphone is placed on the trunk of the palm tree. ...
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2answers
127 views

lcd TV: panels or driver limit capabilities? [closed]

For a LCD panel, if I found a board which offered 120hz refresh rate and 3d active shutter type display could I add it to the panel and could I then get this kind of performance out of the lcd panel ...
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2answers
2k views

reverse engineering camera flash charger

I am trying to understand how exactly the voltage from a 1.5v battery gets connected to a 1000+v capaciter inside these disposable cameras. is there a speciffic chip designed to act as a voltage ...
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2answers
278 views

What to make of this strange snap dome switch configuration?

I'm trying to figure out how to interface a microcontroller with a cheap MP3 player that used snap domes for buttons. I do not have a datasheet for anything on the MP3 player board, because I can't ...
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1answer
837 views

Studying the PCB of a 70s calculator. What were they thinking?

I've been studying the PCB from an ELSI 8002 calculator from 1974. I'm thinking of repurposing the case for a project, though now that I've fixed it (by re soldering the battery connectors) I don't ...
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2answers
375 views

Need help selecting a replacement thermistor

I have a used piece of equipment (basically a specialized laminator) that uses a thermistor to measure the temperature in operation. When I got it, I found that it was heating, but the system never ...
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1answer
1k views

Wireless Power Coil - Is this shielding? Field shaping?

I'm taking apart a Qi wireless power transfer receiver. The coil is etched into the pcb. The entire coil area (approximately 3.75 x 4.5 cm) is covered by a rectangular piece of hard, brittle material. ...
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1answer
2k views

How to reverse-engineer a remote control?

I purchased a few bulbs which are manged via a wireless remote control. I would like to use them with my RPi (to which I would add the relevant transmitter-receiver module). Is there a way for a ...
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1answer
2k views

PWM input specs of Hobbywing Quicrun WP-1040 ESC

What are the controlling input specifications of a Hobbywing Quicrun WP-1040 Electronic Speed Controller (ESC) for brushed motors? I assume it should use the standard PWM with 1 kHz frequency as ...
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3answers
155 views

Data logger component identification

I'm trying to reverse engineer an aging datalogger. Before building my schematic, I would like to identify all the components. There is one component that I can't seem to identify after many hours ...
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1answer
944 views

Is it legal to reverse-engineer an integrated circuit (IC) belonging to a manufacturer [closed]

Can anyone tell me whether it is legal to reverse-engineer a chip to prove the existence of possible backdoor technologies in which the device or IC manufacturer likely is unaware of?
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3answers
252 views

What could this IC be? Trying to reverse engineer a board

Studied EE, haven't used it in 10 years, so pretty rusty. Part 1: the board and how it's connected I'm looking at a very simple current controller that drives 3 different current levels based on a ...
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2answers
1k views

Reverse Engineer Serial Signal

This is a long post as I want to take you through all the work I've done. The TL;DR version is I've got an unknown controller for a mechanical heat pump and I'm trying to reverse engineer the signal ...
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2answers
213 views

Connect to “gold plate” connectors of existing PCB

I got a Bluetooth heating thermostat that I want to modify. The board has an ATmega 169PA, and I identified JTAG and ISP "connectors". They all look like those five round golden plates in the upper ...
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1answer
2k views

Reverse Engineering Camtastic file to PCB in Altium

I've followed the directions found here but after the step where I extract the netlists, when I export to PCB it gives the following error. ...
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1answer
380 views

PCB to schematic

Is there a software package out there that will allow you to layout a board and "populate" it and then render a schematic from that board? I have a few power supplies to fix and no documentation on ...
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2answers
2k views

How to determine if an unmarked device is 110V or 220V?

I have a Chinese laser power supply that the mfg insisted was 110VAC input. The fan runs and everything seems ok, but I only get a fraction of the power out of it (3ma instead of 27ma max). I suspect ...
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1answer
4k views

How do Dualshock 4 pressure sensitive buttons work?

I'm doing a reverse engineering research about the PlayStation 4 controller. I want to know how do the analog buttons work (the triggers in the bottom, not the analog sticks). I've found a nice ...
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3answers
9k views

Is there any way to determine the correct voltage for a stepper motor?

I recently bought a CNC mini-mill at an auction. It is fitted with steppers on the three axis. The X and Y are the same, and the Z is a bit smaller (physically). All the markings were removed from the ...
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773 views

Analyzing the Protocol

I am trying to understand a protocol (shown in figure 1) . For now this I have understood that data is transferred at high to low clock. as shown in figure. and the sync is for every 8-bit. But then ...
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1answer
627 views

How difficult is to reverse engineer a IC Die?

Can anyone tell me how difficult, time consuming and expensive is to reverse all layers of a die ? Say a die from a recent model SoC Processor IC found in smartphone devices such as the Qualcomm ...