DSO138 was designed as a training oscilloscope kit. Simplicity in structure and easiness in assembly/operation are the main targets of its design. For these purposes, DSO138 applies mostly through-hole parts and the heart of DSO138 is a Cortex-M3 ARM processor (STM32F103C8) from ST. It also uses 2.4-inch TFT LCD (320 X 240 dotmatrix, 262K colors) as its display element that will display nice clear waveforms. Detailed assembly instructions are provided in combination with troubleshooting guide and schematic.