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

Filter by
Sorted by
Tagged with
30
votes
2answers
10k views

How can I reverse engineer a simple through-hole board?

How can I reverse engineer a simple through-hole board? Trying to do it by eye gets confusing because it's easy to lose track of component orientation and location while flipping the board over. Maybe ...
24
votes
6answers
7k views

Is it truly impossible to tell what a CPU is doing? [closed]

Computer programmers often recite the mantra that x86 instructions are totally opaque: Intel tells us they are doing something, but there is no hope that anyone can verify what's happening, so if the ...
24
votes
3answers
8k views

Odd PCB Layout for Voltage Regulator

I am reverse-engineering a board which has a Xilinx Spartan 3E FPGA, with VCCAUX powered by a 2.5 volt regulator. Below is the PCB layout for the regulator part of the circuit, and something seems ...
22
votes
4answers
7k views

Why does a mouse need a crystal?

I was looking at this schematic for an old (pre USB) mouse: when I noticed it had a crystal on it (Y1). I was curious why a mouse would need a timer? Wouldn't it be able to use the clock from the ...
20
votes
4answers
10k views

Is it possible to reverse engineer a chip design?

Can we make something like chip reader, which can understand chip design and generate blueprint of it?
17
votes
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 ...
16
votes
1answer
762 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 ...
14
votes
6answers
789 views

Legality of Reverse Engineering

If there was a "law/legal" stack exchange site I'd post it there, but it's in its infant stages in Area 51. I'm a musician and an electrical engineering student. I've designed a modification to the ...
13
votes
3answers
1k views

Is it possible to reverse engineer an analogue IC from a physical example?

Lately I've been investigating custom ICs developed by Roland in the late 70s/Early 80s for their analogue synthesizers. They stopped manufacturing these components around 1989, there are no ...
11
votes
4answers
7k views

Remove an LED from a circuit

I have bought a webcam from which I would like to remove an LED (burning it is also fine for me). By doing so, I could obviously change the way the circuit works, so my questions are: Should I ...
11
votes
3answers
1k views

Why does this EPROM have comb-like structures around the wire bonding pads?

I took some pictures of a Microchip EPROM die from the late 80s / early 90s (I can't recall the exact part number). The wire bonding pads are surrounded by a comb-like structure. What is the purpose ...
9
votes
3answers
11k views

Securing code on an AVR/Arduino and delivering updates

What is the best way to protect code flashed onto any AVR based device from reverse engineering? What is an easy way to provide updates to end users to flash on their own without disclosing the code? ...
8
votes
7answers
13k views

Reverse engineering USB signals

Let's say there is a USB stick that is specifically for storing dates or days or some kind of arbitrary data. In order to access the data you must have the software. Is there any way to analyze the ...
8
votes
1answer
798 views

How does this circuit work? 48VDC relay and 1.2VDC battery from 230VAC

In order to repair a programmable timer plug, I'm doing some "reverse engineering" on it, it's not for the cost (about $5) but more for learning and recycle thought. I draw the scheme but can't ...
8
votes
2answers
233 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. ...
7
votes
5answers
1k views

Reverse engineer a chip or go with a new one and start from scratch?

I'm working on an existing toy product and the chip has been discontinued. We still want to produce more of this product. You press a combination of buttons and it talks to you. What would be a more ...
7
votes
4answers
3k views

Reprogramming a computer mouse's internal IC?

I have a mouse with an internal IC: SPCP168A, having read about it, I discovered that it is specifically designed and programmed for the mouse functionality. I am interested in reprogramming the ...
7
votes
3answers
3k views

What is this small unconnected solder blob on this PCB?

There's a small solder blob in the middle of this one-sided PCB (a switch-mode power supply), surrounded by unmasked board. The blob is 1.5mm in diameter, and the non-masked area is 4mm in diameter. ...
7
votes
5answers
2k views

How to start reverse engineering a circuit?

I have an old controller card from a pc which had to control some stepper engines. But there are several problems with it: The pc isn't working anymore, and I have no access to the program which ...
7
votes
2answers
911 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 ...
6
votes
3answers
761 views

Determining UART RX pin “blind”?

My mom had an old Roku that she no longer wanted so I took it figuring I might be able to hack it and run a generic Linux on it. I took it apart and saw two headers that looked like they might be for ...
6
votes
2answers
14k views

Reverse engineer: How do I remove the black plastic that hides the ics?

I am hacking a circuit and it has this black plastic thing (see picture below) that hides part of the circuit. How can I remove them to see what is inside? What they are for? I think they are for ...
6
votes
2answers
316 views

Is there any possibility of dissecting a microchip to get data from its internal memory?

There are many devices that perform various cryptographic operations inside their microchips. One of their key feature is that the secret keys are stored inside of the hardware and never leave it. ...
6
votes
1answer
187 views

Identifying component from i2c trace & obscure SMD marking

I wanted to poke around one of those sub-10$ smart bands, so I got a couple of them. I opened it and I was able to identify some major components from the SMD markings, including a Dialog DA14580 MCU, ...
6
votes
2answers
3k views

Reverse engineering a 12 pin LCD?

I just found a broken "laser projecting alarm clock". I took it apart, and am interested in only the laser projection arm. This consists of a laser diode (although I suspect that this is actually just ...
6
votes
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 ...
6
votes
3answers
8k 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 ...
6
votes
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 ...
5
votes
4answers
3k views

Do PCBs have schematics? [closed]

I have been studying electronics a bit at home in my spair time. I was wondering if manufacturers make schematics for PCBs? If I could get ahold of something like that i feel that I could understand ...
5
votes
5answers
554 views

Identifying the SPI master

I'm trying to reverse engineer the SPI communications between two chips. But, it's not clear who's master and who's slave. I've found the chip select. Without lifting any pins or cutting traces is ...
5
votes
4answers
342 views

Patented hardware architectures

I have seen patented hardware designs at the level of generic digital block such as shift registers, flip-flops and adders. If a chip maker were to include such a design deep within an ASIC, how can ...
5
votes
3answers
2k views

Is it possible to “crack” an ASIC?

Could someone break an ASIC? If an ASIC is a fully customized, app-specific CPU, is possible to reverse engineer it? I'd imagine the answer in general is no, since to me the only way to do this ...
5
votes
1answer
2k 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 ...
5
votes
2answers
2k views

Pinout of a 3 wire magnetic card reader

I got given a piece of electronics to take apart that has a magnetic swipe card reader built into it. Upon taking it apart the card reader itself (which appears very much like a tape deck head) seems ...
5
votes
2answers
278 views

What kind of serial communication is this?

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 ...
5
votes
2answers
125 views

Determine Attributes of an LED

I have some devices which have purple LED's in them. I need to make another one, but don't know anything else about the LED to buy more. How can I determine the forward voltage and maximum current ...
5
votes
2answers
749 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 ...
5
votes
0answers
2k views

How to calibrate a Kill A Watt meter and understand its hidden service menu [closed]

I found a hidden menu within the Kill A Watt P4400 meter, which is accessed by holding down the Volt and Hz buttons. Although I rendered my meter unable to measure accurately because of my futzing ...
4
votes
4answers
27k views

Determining I2C Address without Datasheet

When setting up I2C communications, I know that it is certainly ideal to have the devices' datasheet(s), and find the I2C address of the device(s) that way. However, in some reverse-engineering ...
4
votes
1answer
896 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?
4
votes
1answer
2k views

Could I connect USB wires to this mysterious device?

In a treasure box, as I call the boxes full of old computer electrical parts, I have found a device marked HannStar MV-4 94v-0 0611 E89382. I'm intentionally linking you to google search so that you ...
4
votes
2answers
660 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 ...
4
votes
4answers
2k views

How hard is it to reverse-engineer a two-way protocol for a beginner with a logic analyzer?

I recently bought a Tacx Flow trainer, which has a handlebar computer, with a 6channel RJ-11 cable between the trainer and the handlebar computer. The computer reads pedal frequency, power and speed, ...
4
votes
1answer
504 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. ...
4
votes
1answer
288 views

Why 2 zero-crossing detection circuits in heater?

I reverse engineered the power board of an electric heater. I think, I understand most aspects of this circuit. One thing is not entirely clear to me though: The circuit seems to have two distinct ...
4
votes
2answers
424 views

Why does timing change in dataframe using Manchester encoding

I have successfully received a couple data frames from an RF transmitter. I compared couple consecutive frames and the timing deviation between them is marginal, so I am convinced it is reasonably ...
4
votes
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 ...
4
votes
2answers
3k views

Reverse-engineering a brushless ESC, could someone help me understand the circuit

So I'm in the process of trying to reverse-engineer a hobby brushless ESC. Above is the schematic for a single half-bridge drive circuit. VIN is 11.1V D1 is an unidentified diode; all that I've ...
4
votes
1answer
433 views

Difficulties reverse engineering a digital bathroom scale

I apologize if this has been discussed elsewhere and for the length of the post. This is a group project and we plan to take the weight value from the scale and send it via a WiFi connection to ...
4
votes
3answers
798 views

How to reverse engineer controller outputs of a sprinkler control box?

I want to replace the controller of a sprinkler control box with my own design, while keeping the backplane and module(s). The controller has a 14 pin ribbon cable connection to the backplane and 4 ...