Here’s a preview of the curve tracer based on the RP2040. It works with an ILI9341 TFT SPI display, including touch support.

Alongside the Rapid_Development board for the Pico, it uses a constant current source built with the HC595, and a new Power Board for driving UCE.

The system runs on 12V, powered by a single 18650 Li-ion cell. The Power Board features a 12-bit ADC (MCP3204), a dual-channel DAC (MCP4822), and a power amplifier (TCA0372).

It supports measurements of standard bipolar transistors (NPN/PNP), diodes (including Zeners < 12V), JFETs, and MOSFETs.

The hardware is nearly complete — next steps are testing the software and the touchscreen interface.
 
 The Schematic Diagram: 

   

 
 Some fields are also changeable with 2 rotary encoders.
 
 In the next days I will present the new Power-Board for changing Uce with Dual-Dac.
 
 Now I have changed the current-source to 4 bit.
 
 You can change now the base-current from 0 to 150 µA with stepwide 10 µA,
 from 0 to 300 µA with stepwide 20µA
 and from 0 to 750 µA with stepwide 50 µA.