// pn: sps-rl-01-02 · educational / evaluation hardware
RadioSonic is a portable, low-cost signal processing hardware platform for educational and evaluation use. The board provides a hands-on environment for working with real-time audio signals and exploring core DSP concepts: digital filtering, convolution, Fourier analysis, and wavelength-consistent "RF in slow motion" demonstrations.
// key capabilities and system highlights
// what’s onboard
Two omnidirectional microphones with a usable frequency range of 100 Hz to 10 kHz. Spaced 30 mm apart for audio beamforming experiments; this spacing corresponds to approximately one-half wavelength at about 5.7 kHz in air.
Dual-core 32-bit Xtensa® LX7 processor with floating-point support and vector extensions suitable for real-time DSP. Integrates I²S audio interfaces, DMA controllers, timers, and high-speed serial interfaces for time- and frequency-domain algorithms: filtering, spectral analysis, modulation, beamforming.
On-chip memory plus 8 MB module-integrated Quad-SPI flash and 8 MB Octal-SPI PSRAM. Integrated Wi-Fi connectivity provides optional data streaming, control, and instrumentation. Espressif datasheet →
Texas Instruments TLV320AIC3204 (AIC3204) is a flexible, low-power stereo audio codec with programmable inputs and outputs, PowerTune capabilities, and parameterizable signal-processing blocks.
Support for external storage via a microSD card connector with push-push ejector.
An ADC input is accessible via a footprint for an optional potentiometer at reference designator R22. The potentiometer wiper (pin 2) connects to IO5 (ADC1_CH4) on the ESP32-S3 module, enabling simple signal-acquisition and control experiments.
Compatible part: Same Sky PT01-D130D-B503 →
// connectors and headers
Click any row to expand for details.
3.5 mm stereo audio input jack. Accepts single-ended line-level signals with a maximum AC signal swing of 0.75 Vpeak when the codec common-mode voltage is set to 0.75 V (or 0.9 Vpeak at CM = 0.9 V; CM is configurable via codec registers).
Input impedance is configurable from 15 kΩ to 79 kΩ depending on gain and routing. Each channel includes a 10 µF DC-blocking capacitor for a worst-case high-pass cutoff of approximately 1 Hz.
3.5 mm stereo headphone output jack. Single-ended output capable of driving 16 Ω headphones up to 0.5 VRMS at full-scale. 100 µF DC blocking capacitors give a high-pass cutoff near 100 Hz with a 16 Ω load.
3.5 mm stereo line-level output jack. Intended for connection to high-impedance loads (nominal 10 kΩ single-ended). Provides up to 0.375 VRMS at full-scale. 10 µF DC-blocking capacitors give a high-pass cutoff near 1.6 Hz with a 10 kΩ load.
USB 2.0 Type-C receptacle for host PC connectivity and +5 V external power, used for board operation and battery charging.
2×6, 2.54 mm pitch dual-row female header providing an auxiliary expansion interface for up to two additional audio codecs. Supports up to four additional microphones for linear-array and beamforming demos with synchronized multi-channel acquisition.
2×20, 2.54 mm pitch dual-row female header compatible with standard Raspberry Pi mechanical layouts. Provides digital GPIO, power rails, and control signals for external hardware expansion and prototyping.
2×5, 2.54 mm pitch dual-row header footprint providing DC-coupled access to Line In, Line Out, Headphone, and Microphone Left/Right signals. Intended for advanced debugging, instrumentation, or external analog interfacing.
1×2, 2.54 mm pitch single-row male header connected to Line Out Left and Line Out Right (no ground pin). Pin 1, indicated with a dot on PCB silkscreen, connects to Line Out Left. Intended for connection to an external amplifier or downstream analog circuitry; reference ground is available on other connectors (e.g., J7 GND pins).
2.0 mm pitch JST-PH-compatible vertical PCB male header for connection to an external 3.7 V lithium-ion battery pack. An integrated battery charger automatically charges the external battery when USB power is supplied. An on-board charge-status LED (D5) is lit when the battery is charging.
Example compatible battery: 2000 mAh JST-PH pack →
// pin-out reference
| Pin | Signal | Direction | Notes |
|---|---|---|---|
| 1 | - | - | Not connected |
| 2 | +5V | Power | USB-derived supply |
| 3 | I2C_SDA | I/O | I2C data |
| 4 | +5V | Power | USB-derived supply |
| 5 | I2C_SCL | I/O | I2C clock |
| 6 | GND | Power | Ground |
| 7 | EXT_GPIO_0 | I/O | User GPIO |
| 8 | UART1_RX | Input | UART receive |
| 9 | GND | Power | Ground |
| 10 | UART1_TX | Output | UART transmit |
| 11 | EXT_GPIO_1 | I/O | User GPIO |
| 12 | PCM_CLK | Output | Audio clock |
| 13 | EXT_GPIO_2 | I/O | User GPIO |
| 14 | GND | Power | Ground |
| 15 | EXT_GPIO_3 | I/O | User GPIO |
| 16 | - | - | Not connected |
| 17 | EXT_GPIO_4 | I/O | User GPIO |
| 18 | - | - | Not connected |
| 19 | EXT_SPI_MOSI | Output | SPI MOSI |
| 20 | GND | Power | Ground |
| 21 | EXT_SPI_MISO | Input | SPI MISO |
| 22 | - | - | Not connected |
| 23 | EXT_SPI_SCK | Output | SPI clock |
| 24 | EXT_SPI_CS_0 | Output | SPI chip select |
| 25 | - | - | Not connected |
| 26 | - | - | Not connected |
| 27 | ID_I2C_SDA | I/O | EEPROM SDA |
| 28 | ID_I2C_SCL | I/O | EEPROM SCL |
| 29 | - | - | Not connected |
| 30 | GND | Power | Ground |
| 31 | - | - | Not connected |
| 32 | - | - | Not connected |
| 33 | - | - | Not connected |
| 34 | GND | Power | Ground |
| 35 | PCM_FS | Output | Audio frame sync |
| 36 | - | - | Not connected |
| 37 | - | - | Not connected |
| 38 | PCM_DOUT | Output | Audio data out |
| 39 | GND | Power | Ground |
| 40 | PCM_DIN | Input | Audio data in |
| Pin | Signal | Direction | Notes |
|---|---|---|---|
| 1 | +3.3V | Power | Regulated +3.3V supply |
| 2 | CODEC_1_CS | Output | SPI chip select for Codec 1 |
| 3 | MCLK | Output | Master clock |
| 4 | CODEC_2_CS | Output | SPI chip select for Codec 2 |
| 5 | WCLK | Output | Audio serial data bus word clock |
| 6 | BCLK | Output | Audio serial data bus bit clock |
| 7 | CODEC_DOUT | Input | Audio serial data bus data output |
| 8 | CODEC_DIN | Output | Audio serial data bus data input |
| 9 | SPI_MOSI | Output | SPI MOSI |
| 10 | SPI_SCLK | Output | SPI Clock |
| 11 | SPI_MISO | Input | SPI MISO |
| 12 | GND | Power | Ground |
| Pin | Signal | Direction | Notes |
|---|---|---|---|
| 1 | LIR | Input | Line-in right |
| 2 | LIL | Input | Line-in left |
| 3 | HPL | Output | Headphone left |
| 4 | HPR | Output | Headphone right |
| 5 | LOR | Output | Line-out right |
| 6 | LOL | Output | Line-out left |
| 7 | MIC_R | Input | Microphone right |
| 8 | MIC_L | Input | Microphone left |
| 9 | GND | Power | Ground |
| 10 | GND | Power | Ground |
// usage and compliance
RadioSonic™ is a trademark of SigPro Labs, LLC.
Get the board for $39, or bundle it with a course for 10% off.