Many devices use infrared (IR) as a signalling medium like, for example, RGB LED strip controllers
modules and some TV controllers. Often times these signals aren’t meant for secure applications which means the functionality can be reproduced by simply replaying back the received signal verbatim. Sometimes, enterprising hackers want to reverse engineer the IR signals, perhaps to automate some tasks or just to get a better understanding of the electronics we use in our everyday life. To help in this effort, [dilshan] creates an open source hardware IR cloner device, capable of snooping IR signals and retransmitting them.
The IR cloner is a sweet little IR tool that can be used to investigate all sorts of IR signals.
In addition to the source code and design files, [dilshan] has also taken care to create detailed documentation as an addendum to the video on assembly and usage.
The IR cloner itself is a board that’s just over 41mm by 31mm with mixed surface mount and through hole components. The device has an LD271 IR LED that can transmit in the 880nm to 950nm range with a TSOP181 IR receiver that can receive in the same range. The STM8S003F3 microcontroller sits at the heart of the device. Depending on jumpers, wiring and battery connections, the device can take an external battery pack ranging from 3V or 5V to 9V. The board has an eight pin DIP that is meant to seat a 24LC32 32kbit EEPROM. Header pins are available to attach to an 4×4 pushbutton matrix that is meant to control the unit.
The main workflow looks to be setting the functional mode with the 4×4 pushbutton matrix with the EEPROM acting as storage. The signals can be replayed directly after receipt or can be analyzed more in depth by removing the EEPROM and downloading the saved signal data. [dilshan] recommends using something like an CH341A based programmer to read stored values from the EEPROM.
Having the IR cloner around would be the perfect tool to not only help reverse engineer something like a PixMob wearable LED wristband or an IKEA LED lamp but to use and hack on them yourself.