121gw-re

Reverse engineering the EEVBlog 121GW

If you're just here to learn about the meter, start with the wiki up top.

• The pdfs directory contains official documentation on the multimeter hardware (manuals, datasheets, etc.).
• The binaries directory contains the firmware and bootloader release binaries.
• The database directory contains the IDA database for the firmware. Please read the DATABASE readme before doing anything with it.

Routines & Tables

The routines directory contains reimplemented routines from the firmware. These can be implemented in any reasonable language that will not require a large amount of external libraries. Preference is given to those which work to teach about the routine. Read and run the meas_ohms_calc_50M_offset.py code for a demonstration.

The tables directory contains C header definitions for the various firmware tables. When writing such a file, keep in mind the following:

• Use appropriate datatypes, e.g. const, unsigned int, or uint16_t.
• Annotate the different sections of the table with their use.
• IDA is sometimes incorrect about displaying signed numbers; use the correct signed-ness in the definition.
• The table can almost certainly be found in the .c file output by IDA. Just clean up the above issues and it's good to go.

Contributing

There are several ways to contribute to the project.

• If you have a GitHub account, you can freely edit the wiki. Check the Questions page and see if you can answer one of them.
• If you would like to contribute to the IDA database, please read the instructions in the DATABASE readme.
• If you would like to contribute a file, such as a dump for binaries or a new example for routines, please either open an issue and provide a link to the file, or fork the repository and create a pull request.