Despite being built on open-source code, the DSO-TC2’s firmware is not open source. Fnirsi does not release the source code or the toolchain. This has frustrated the hacker community, who would otherwise fix bugs, add features (like better triggering or serial decoding), or port the firmware to other devices.
As a result, a small but dedicated group of reverse engineers has attempted to dump and analyze the firmware. They discovered that:
This closed-source approach is a commercial decision: Fnirsi wants to prevent clones and protect their “secret sauce,” even though the sauce is borrowed. The result is a device that cannot be fully customized or repaired through software—a loss for the maker community that the device ostensibly serves.
Unlike simple multimeters, the FNIRSI DSO-TC2 runs a real-time operating system. The firmware controls:
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.).
The stock firmware on the TC2 is often criticized for slow user interface response and minor bugs.
FNIRSI DSO-TC2 is a handheld 2-in-1 device that combines a digital oscilloscope with a transistor tester. Below are the details for finding and installing its firmware. Official Firmware & Resources fnirsi dso-tc2 firmware
You can download the latest official firmware and user guides directly from the FNIRSI Manuals & Firmware Manufacturer Site FNIRSI Official Alternative Support : For general software utilities, check the Software Downloads How to Upgrade Firmware Updating the generally follows a "drag-and-drop" method via a computer Preparation USB Type-C data cable
(ensure it supports data transfer, not just charging) to connect the device to your PC while it is Enter Update Mode
Some users report that the device may automatically enter a bootloader mode if connected while off and then powered on.
For similar FNIRSI models, a common shortcut is holding specific buttons (like the keys) while powering on to trigger the update mode. Transfer File : Once in update mode, a drive named (or similar) should appear on your computer. Copy & Update : Copy the downloaded firmware file (usually a
file) into this drive. The device will typically display "Update completed" once finished. Community & Custom Firmware Because the component tester portion of the
is based on the popular "transistor tester" project, there is significant community interest in porting or improving the software EEVblog Forum Despite being built on open-source code, the DSO-TC2’s
: A major hub for technical discussion and shared firmware modifications for FNIRSI devices is the EEVblog Testgear Forum
In the world of budget electronics, the FNIRSI DSO-TC2 Go to product viewer dialog for this item.
firmware story is one of a "finished" device that rarely looks back. Unlike its successors, the
is often viewed by the community as a static tool—reliable for its price but notoriously difficult to update due to a lack of official support and a "one-and-done" design philosophy. The Quest for Updates
For most users, the "story" begins with a search for bug fixes or new features, only to find that the official FNIRSI Download Center focuses almost entirely on newer models like the Go to product viewer dialog for this item. Go to product viewer dialog for this item. The "Static" Reality: While devices like the
have received multiple firmware revisions (v0.0.3 to v0.0.7) to fix UI and measurement issues, the remains largely on its factory version. This closed-source approach is a commercial decision: Fnirsi
Community Frustration: Users on forums like EEVblog describe the device as a "toy" where what you see is what you get. The lack of updates is often attributed to the original design being contracted out, leaving FNIRSI with limited ability to patch the software. The Risks of "Modding"
Because official updates are scarce, the story often turns into a cautionary tale of "bricking" or failed attempts: Incorrect Files: Attempting to force-load firmware from the
or other models can result in a blank screen or shifted displays.
The Hardware Wall: Some users have tried to port open-source "TransistorTester" firmware to the device, but hardware limitations—like the way FNIRSI integrated the MCU—often make these third-party stories end in failure. How the Process Usually Goes (For Other Models) If FNIRSI were to release a update, the narrative would likely follow the path of the
Here’s a concise review of the Fnirsi DSO-TC2 focused specifically on its firmware situation, based on user reports and technical analysis from electronics forums (EEVblog, Reddit, etc.).