DSO138 was designed as a training oscilloscope kit. It contains only the basic oscilloscope functions with no fancy features. Simplicity in structure and easiness in assembly/operation are amongst the main highlights of the design. For these purposes, DSO138 uses mostly through-hole parts. The heart of DSO138 is a Cortex-M3 ARM processor (STM32F103C8) from ST. It uses a 2.4-inch TFT LCD (320 X 240 dotmatrix, 262K colors) that displays crisp and clear waveforms. DSO138 is partially open-sourced. This opens the possibility for users to add different features or develop new applications on the hardware. Major features of DSO138: Analog bandwidth: 0 – 200KHz Sensitivity: 10mV/Div – 5V/Div Sensitivity error: lessthen 5% Vertical resolution: 12-bit Timebase: 10us/Div – 500s/Div Record length: 1024 points Built-in 1KHz/3.3V test signal Waveform frozen (HOLD) function available Save/recall waveform