This course  covers developing an IoT-enabled oscilloscope for hands-on learning in embedded systems and IoT. Inspired by DIY tutorials (e.g., the linked Vimeo video on a portable 3-in-1 test device), it creates a low-cost tool (<$50) for signal visualization, analysis, and wireless data sharing via WiFi/BLE.

Required Components

• MCU: ESP32 or STM32 for processing.
• ADC: Built-in or external (e.g., ADS1115) for signal sampling.
• Wireless: WiFi/BLE module (integrated in ESP32).
• Input: Probes, voltage dividers, protection circuits.
• Display: OLED (e.g., SSD1306).
• UI: Buttons/encoders.
• Power: Battery/USB with regulators.
• Extras: DAC, resistors, capacitors, PCB.

MCU for Processing

Use a 32-bit MCU like ESP32 (240MHz, dual-core) for signal processing, ADC control, and IoT. Program in C/C++ via Arduino/ESP-IDF. Ensure sufficient RAM (256KB+) for data buffering.

WiFi, BLE, and Other Wireless Communications: Definitions, Choices, and Considerations for Data Transmission

Wireless communication is key to making the oscilloscope “IoT-enabled,” allowing it to transmit captured waveforms, measurements, or alerts to smartphones, computers, or cloud servers for remote access and analysis.

• WiFi: A high-bandwidth wireless standard (IEEE 802.11) operating at 2.4GHz/5GHz, supporting data rates up to 100+ Mbps over ranges of 50-100 meters indoors. It’s excellent for streaming large datasets like high-resolution waveforms.
• Bluetooth Low Energy (BLE): A low-power variant of Bluetooth (version 4.0+), designed for short-range (10-50 meters) communication at 1-3 Mbps. It excels in battery-powered devices, transmitting small packets like sensor readings or basic scope data.
• Other Wireless Options:
  • Zigbee: Mesh networking protocol for low-power, medium-range (10-100 meters) setups, ideal for home automation but with lower data rates (~250 kbps).
  • LoRa: Long-range (up to 10+ km) low-power wide-area network (LPWAN) for sparse data transmission, suitable for remote monitoring but not high-speed scope data.
  • Cellular (e.g., NB-IoT or LTE-M): For global connectivity without WiFi, but higher cost and power draw, best for outdoor deployments.

How to Choose a Good Board for This Design

Selecting the right development board is crucial for prototyping and scaling your IoT-enabled oscilloscope. Focus on boards that balance performance, peripherals, and ecosystem support. Key criteria include:

Availability of Peripherals like ADC, I2S, DAC:

• ADC: Essential for signal input. Look for high-resolution (12-bit+) and fast sampling rates (100kSPS+). ESP32 has a built-in 12-bit ADC, but for precision, boards with external ADC support (e.g., via SPI) are better.
• I2S (Inter-IC Sound): Useful if incorporating audio analysis or digital signal processing (e.g., for waveform audio output). Boards like ESP32 or STM32 Nucleo support I2S natively for interfacing with microphones or speakers.
• DAC: Needed for signal generation in a 3-in-1 device. Choose boards with 8-12-bit DACs (e.g., ESP32’s integrated DAC) to output test waveforms.

Other factors:

• Processing Power and Memory: At least 100MHz CPU with 256KB+ RAM for handling data buffers.
• Wireless Integration: Built-in WiFi/BLE to minimize external components.
• GPIO and Expansion: Ample pins for probes, displays, and sensors.
• Power Efficiency: Low-power modes for portable use.
• Community and Tools: Boards like ESP32 or Raspberry Pi Pico have extensive libraries and tutorials.
• Cost and Availability: Aim for under $20, with easy sourcing.

Here IndusBoard is selected that qualify all requirement