ThingPulse, founded by embedded computing specialists Daniel Eichhorn and Marcel Stör, has announced the impending launch of an Espressif ESP32 development board built with low power draw in mind: the ePulse Feather.
Built around Espressif's ESP32-WROVER-E-N8R8 module, which includes either the ESP32-D0WD-V3 or ESP32-D0WDR2-V3 system-on-chip, ThingPulse's ePulse Feather borrows Adafruit's Feather form factor and pinout for a low-cost development board designed for battery-powered projects. As a result, you'll find a battery connector and lithium-polymer charging circuit included as standard — but it's the board's low power draw that makes it ideal for long-life battery projects.
According to ThingPulse's own measurements the board, which was brought to our attention by Linux Gizmos, draws 12-27µA in its deep-sleep mode — from which it can be woken by timer or interrupt, in order to connect the built-in 802.11b/g/n Wi-Fi or Bluetooth 4.2 Low Energy (BLE) radios to a network and transmit data.
"The VIN pin accepts voltages between 3V3 and 6V," the company explains. "When the ePulse board is in deep sleep it only consumes between 12uA (above 3.3V) and 27uA (below 3.3V). Most ESP32 and ESP8266 board consume around 100 – 130uA.
"We also made sure that the integrated serial-2-usb chip is only consuming power when the device is powered through the USB port. Please note that to reduce standby power consumption this module comes only with a LED indicating charging status. No other status LEDs are included."
The ESP32 module at the board's heart includes two Tensilica Xtensa LX6 cores running at up to 240MHz, 520kB of static RAM plus an additional 16kB of SRAM in its real-time clock (RTC) block, plus an additional 8MB of pseudo-static RAM (PSRAM) and 8MB of flash connected via quad-SPI. There are 20 general-purpose input/output (GPIO) pins brought out to the sides of the breadboard-friendly PCB, following the Adafruit Feather pinout standard.
The board is to launch in late February at $14.95, ThingPulse has confirmed — with pre-orders open now at the discounted price of $12.50, including male header pins.