Handheld Oscilloscope Multimeter using Raspberry Pi Pico

In our project, a handheld instrument that combines an oscilloscope, a digital multimeter and a function generator was designed and tested using the Raspberry Pi Pico and a 3.5-inch TFT display. The dual-core firmware keeps sampling and rendering independent of the user interface, and the simple analogue front-end handles inputs of 0–30 V. The prototype achieves a 20 kHz bandwidth, 12-bit resolution, DC voltage accuracy within 1% and a 1 Hz–10 kHz function generator, and runs for four to six hours on one charge. Its cost of about USD 25–35 is far below that of commercial equivalents. In the future, the internal ADC can be replaced by an external converter such as the MCP3204 or AD9226 to reach 1 MHz or more of bandwidth, the PWM generator by a DDS chip such as the AD9833 [19] with sweep and modulation, and Wi-Fi or Bluetooth can be added through an ESP32 for data logging and FFT display on a phone or laptop. Power-saving measures from [10], a fabricated PCB and guided measurement tutorials for students would further improve the instrument.

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