For smart home and automation applications, you might require a user button featuring advanced wireless connectivity like Wi-Fi and Bluetooth Low-Energy. In most cases, this wireless connectivity helps the operator connect the user button to its hardware system. Also, with the recent innovation and adoption of RISC-V instruction set architecture, manufacturers and makers desire to produce embedded devices that feature at least one RISC-V component. As we saw, Sipeed’s Tang Nano 9K does not include a hardcore RISC-V processor but shows compatibility with RISC-V softcore PicoRV. A German maker, [makermoekoe] designed a compact Wi-Fi and BLE IoT button, named Picoclick C3T IoT button, which can be used as an actuator for IFTTT automation (“an automation tool that lets you script actions together across apps and services, without needing to code”) or as an MQTT device.
The IoT button is built on the ESP32-C3 RISC-V processor which is clocked at 160MHz frequency. This ultra-low-power system-on-chip featuring a single-core CPU supports wireless connectivity IEEE 802.11b/g/n and Bluetooth 5. For the Wi-Fi subsystem, the die supports Station mode and SoftAP mode. State-of-the-art power and RF performance along with reliable security features ensured by cryptographic hardware accelerator, random number generator, and permission control on accessing internal memory and peripherals.
Specifications of Picoclick C3T IoT button
- SoC: ESP32-C3 RISC-V processor @160MHz
- 32-bit RISC-V single-core processor
- CoreMark score: 1 core at 160MHz: 407.22 CoreMark; 2.55 CoreMark/MHz
- Memory: 400kB SRAM (16kB for Cache) and 8kB for RTC
- Interfaces: SPI, Dual SPI, Quad SPI, QPI
- Peripheral Interfaces: 22x GPIOs, 3x SPI, 2x UART, 1x I2C, 1x I2S, LED PWM Controller, USB Serial/JTAG controller, Remote control peripherals, General DMA controller
- Analog interfaces: 2x 12-bit SAR ADCs, 1x temperature sensor
- Wireless connectivity: Wi-Fi IEEE 802.11b/g/n supporting 20MHz and 40MHz bandwidth in 2.4GHz band, Bluetooth LE: Bluetooth 5 and Bluetooth Mesh
- Power consumption: 3µA in standby mode
- Powering options: Single-cell LiPo battery and USB Type-C for battery charging
- LED: WS2812 2020 RGB LED
- Dimension: 10.5×18 mm
“The Picoclick makes use of the native USB/JTAG-console of the ESP32-C3 and therefore doesn’t need a USB2Serial adapter like a CP2102N or CH340,” the maker explains. “Flashing and working with the serial console/monitor can be done as usual.”
If you are interested in purchasing the hardware, priced at $22.00 on the Tindie store.