The DSO-TC2 does not usually update via Wi-Fi or a simple USB drag-and-drop. It uses a DFU (Device Firmware Update) mode, which is common for STM32 chips.
What you need:
The Process:
Unlike simple multimeters, the FNIRSI DSO-TC2 runs a real-time operating system. The firmware controls: fnirsi dso-tc2 firmware
Many users never update their firmware, often missing out on critical performance improvements. In fact, FNIRSI released several silent revisions of the DSO-TC2, and the firmware differs between hardware versions (v1.0, v1.1, etc.).
As of 2025–2026, Fnirsi has released only a handful of firmware updates for the DSO-TC2. These updates fixed minor bugs (e.g., screen calibration, battery readout) but added no new features. The company appears to have moved on to newer models like the DSO-TC3 and DSO-TC4, which share similar firmware but with minor tweaks.
This update scarcity means that any remaining bugs—such as occasional freezing when switching modes, incorrect capacitance readings above 100 µF, or unstable triggering at low signal levels—will likely never be fixed. For a tool that relies on firmware for its core functionality, this planned obsolescence is disappointing. The DSO-TC2 does not usually update via Wi-Fi
The DSO-TC2 is a 2-in-1 oscilloscope (200 kHz bandwidth) + transistor tester. Its firmware is closed-source and updated via a .upd file using a Windows PC tool (no OTA or macOS/Linux native support).
The device should now enter Bootloader Mode. You will see text on the screen saying "Erasing..." followed by "Writing..." and finally "Update Complete" or "Success."
This process takes about 30 to 60 seconds. Do not touch the device. The Process:
When you unbox your DSO-TC2, it comes with stock firmware that was burned onto the chip months before the device arrived at your door. Since then, FNIRSI engineers may have released multiple updates. Updating your FNIRSI DSO-TC2 firmware can provide:
The most compelling chapter in the TC2 firmware saga involves the relationship between the manufacturer and the community.
For a long time, FNIRSI was notoriously secretive about their source code. While they eventually released some code, the community quickly realized that the provided source didn't match the optimized binaries running on the devices. This led to a wave of skepticism.
However, the real drama started when people tried to modify the firmware. Unlike more hacker-friendly brands, FNIRSI devices were often protected. There were reports of "anti-tamper" mechanisms where, if the firmware detected unauthorized modification or if the user attempted to downgrade, the device would lock up or "brick" itself. This turned a $50 tool into a paperweight, sparking outrage on forums like EEVblog and Reddit. It created a "cat-and-mouse" game: FNIRSI would patch security holes, and hackers would find new exploits to unlock the bootloader.