The idea to built this device was my daily job with troubleshooting some process failures on LED drivers produced in my factory. But it can be used in every electronic circuits. What you only need is an oscilloscope with XY mode, on the screen we can visualize current flowing through tested component called DUT (device under test) , we get V-I curve and with some experience we can say if this component is OK or NOT. Of course if we measure components in circuit we have to take into account other connected components . It can plot very nice curves :)
My device is based on Arduino Nano. To generate sine wave AD9833 module have been used. Parameters like Frequency and Output Voltage is displayed on SSD1306 0.96" OLED display.
Signal amplitude is regulated by digital potentiometer MCP41010.
I've decided to use five testing frequencies : 50Hz, 500Hz, 2kHz, 10kHz, 50kHz. Testing voltage is regulated by 1V steps up to 26Vpp.