A Nixie bargraph tube IN-13 driver module which includes high-voltage DC-DC and control circuit. All it needs is 5v and control signal: it can be controlled by analog voltage (0 to 5v) or by I2C.

After I saw cnlohr nixie driver project I've thought that this project also can be used to control IN-13 tube. The tube basically needs a 140V power supply and a servo circuit to control cathode current. And CH32V003 appear to be a perfect chip for such project as it also includes an opamp, which I used to close the control loop.

So I wanted to make a module which is ready to be connected to Arduino or any other MCU, without any additional circuits.

The module can be controlled by analog voltage on pin Vctrl (default mode) or via I2C interface. In case of analog control the MCU samples voltage and converts it into PWM signal which is then filtered and going to the cathode current control servo. In case of I2C the code is directly used to generate PWM with specified duty cycle.