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
253
questions
0
votes
1answer
89 views
PCB power planes and routing question
Ok this is my first time trying some kind of reverse engineering and I have few experiences in PCB testing so it may be a basic question.
Basically I am trying to get the schematics for an 8 channel ...
0
votes
2answers
179 views
Help with reverse engineering an LED driving circuit
I am trying to reverse engineer an LED driving circuit. The schematic I generated from analyzing the board looks as follows:
The main circuit is this one: https://www.monolithicpower.com/pub/media/...
0
votes
0answers
171 views
Identify TI motor driver IC (from old HP printer) or its control protocol
For fun, and as an exercise in reverse engineering junk hardware, I am trying to understand the internals of an HP DeskJet 840c printer from 2001.
Specifically I am trying to understand how the motor ...
4
votes
3answers
412 views
Help Understanding a PCB Circuit from Cordless Hot Glue Gun
I'm trying to understand the circuit in this PCB taken from a cordless hot glue gun. Battery voltage is 18-19v. I've been able to identify most of the components but not all. And most importantly I ...
-1
votes
1answer
394 views
Voltage convert from 110v to 220v
Should the ceramic heater in soldering iron be changed to convert the iron from 110 volt to 220 volt? What about the Thyristor?
I know getting new iron is better, but my question is just for learning....
4
votes
1answer
412 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 ...
1
vote
1answer
2k views
Flashing nordic n51802
I have a Chinese rip-off game pad, which has an n51802 which is by nordic. I want to flash my own firmware but i’m unable to find any information about it. I can put it in DFU mode, so it is flashable,...
0
votes
1answer
320 views
Serial Wire Debug (SWD) Enumeration
When debugging or accessing hardware firmware, JTAG and SWD can be really helpful to the developer, engineer or reverse engineer.
When looking at an unknown board/device tools such as JTAGEnum or ...
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 ...
3
votes
0answers
1k views
Dumping contents of read-protected PIC
I have a need to read out the flash memory of a read-protected PIC16F57 (this is for legal purposes). From my basic research, there appears to be no way of doing this short of decapping it and reading ...
3
votes
1answer
268 views
Reverse engineer a custom (failed) transformer
I am attempting to repair an aged air conditioner I have tracked the issue to a failed secondary on a current transformer.
Very helpfully schematics are available for the circuit board and inform me ...
0
votes
3answers
278 views
Air Purifier Circuit Mod Help [closed]
I have an air purifier I would like to modify the PCB to an always on state at high setting when plugged in. This would allow me to control the device with and Amazon Echo compatible smart plug.
...
-1
votes
1answer
96 views
Reverse engineering to MSP432P401R LaunchPad Development Kit [closed]
I have this LaunchPad Development Kit(MSP432P401R):
I connected the kit to the computer using USB (Like in the image), and through the PuTTY software I was able to receive the output and input to the ...
1
vote
1answer
244 views
How to interpret this CAN bus data and find an equation?
I am trying to reverse engineer the data sent from an old CAN bus data logger. It sends a single ID which is selectable from a dip switch.
The only bit of data I am struggling with is the RPM
I plan ...
0
votes
1answer
548 views
How to connect LCD backlight wires [closed]
I have bad caps in my LCD monitor. While taking it apart, I disconnected the LCD backlight wires to get to the power supply. I blame bad product design and my own stupidity for not checking how the ...
1
vote
0answers
42 views
Trying to identify part driving in magnetic levitator. Maybe a 2.5 V switching regulator?
Its from a toy magnetic levitator purchased on alibaba. I wanted to understand and modify it but the key component has the markings sanded off. I'm pretty sure I got the pins figured out and know how ...
6
votes
1answer
229 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, ...
0
votes
2answers
399 views
Help identifying a SOP-18 IC (labels removed) by reverse engineered circuit
I have a SOP-18 IC (0.65mm pin pitch) which I need to identify. It seems the vendor removed the labels on top of the IC, so I need your help.
The IC is usually connected to a bunch of LEDs and two ...
0
votes
0answers
149 views
Help with assessing maximum operating voltage of a circuit
I am designing a field charger for charging lipo batteries while I am out flying and on the go and I already have a huge 16000mah 4S lipo available that I could use to charge my 1300mah 4S and 2200mah ...
0
votes
4answers
4k views
Reversing the Direction of An Induction Motor?
I have this motor I salvaged from a dryer, and I'm interested in reversing the direction of spin because it spins in the direction opposite of typical machine threads.
The Capacitor is shown at the ...
0
votes
1answer
224 views
Figuring out the protocol of an SPI device without a datasheet
I am pondering about interfacing with the iPad Mini 2 touch panel. It seems that no one has successfully done this and/or published anything about it, so I want to take a stab at it.
As far as I ...
4
votes
1answer
540 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 ...
1
vote
4answers
272 views
Does modern market has IC chips which can be fully reverse-engineered with optical microscope?
I'm planning a new course on digital electronics and semiconductors devices for my university. I think, it would be great to go to the lowest available level of abstraction, or, at least, slightly ...
4
votes
3answers
1k 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 ...
1
vote
2answers
248 views
Decoding a Two-Wire SPI-esque Serial Protocol
I'm working on a project that involves the optical sensor from a mouse. I've got the original control PCB (still populated, save for the optical sensor itself), and I've got the optical sensor on my ...
2
votes
1answer
298 views
Identify a 320V DC Brushless IC Power MOSFET(?) Driver
I need some help identifying this IC. It comes from a bladeless fan.
It is presumably a 230V Power MOSFET(?) element connected to the FCM8201 Three-Phase Sine-Wave BLDC Motor Controller.
The thick ...
6
votes
4answers
4k 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 ...
1
vote
0answers
135 views
Reverse Engineering a transmitter circuit
This circuit is from a radio transmitter electric gate keyfob. -> http://www.easygates.co.uk/product_info.asp?ProductID=340
I want to make my own keyfob.
How would I go about finding or creating a ...
0
votes
2answers
181 views
Can any part of Intel's (RdRand) random number generator be visually inspected?
A random number instruction RdRand, has been added to Intel's Ivy Bridge processors that (allegedly) draws upon a hardware entropy circuit. The architecture is (allegedly) something like this:-
The ...
0
votes
4answers
541 views
How do I figure out the windings of a transformer
I have a transformer. It is a custom wound transformer for a old linear powersupply. As is common, it has two primary windings for supporting 115V and 230V operations (or, 120V and 240V as is now more ...
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 ...
0
votes
1answer
258 views
Replace CR2032 by li-ion reverse engineering
I want to replace my Wireless door bell by lithium-ion 3.3 V-4.2 V but I don't know if the circuit is design for that. It work with CR2032 3 V max.
I think I identified Attiny85 on the PCB, I can ...
1
vote
3answers
307 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 ...
2
votes
2answers
1k views
Why does my I2C write get NAK'd?
I am trying to interface to an existing device, for which I do not have documentation. The device exposes a 5v I2C interface with several IC's on the bus. I have used a logic analyzer to capture the ...
1
vote
1answer
790 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'...
7
votes
2answers
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 ...
0
votes
1answer
668 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 ...
0
votes
1answer
207 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 ...
3
votes
3answers
598 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 ...
8
votes
2answers
263 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. ...
1
vote
2answers
1k 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 ...
1
vote
1answer
160 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 ...
0
votes
2answers
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, ...
-2
votes
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....
3
votes
1answer
489 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.
...
2
votes
2answers
428 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 ...
0
votes
3answers
633 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 ...
2
votes
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 ...
3
votes
1answer
853 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 ...
2
votes
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 ...
