Olimex's Open Hardware ESP32-S2 Dev Board Draws Just 30µA in Deep Sleep, Targets Battery Projects

Open hardware specialist Olimex has announced a new Espressif ESP32-S2 development board, targeting low-power Internet of Things (IoT) projects with a deep sleep power draw of just 30µA.

"ESP32-S2 is new SoC from Espressif which fills the gap between ESP32 and ESP8266," Olimex explains. "It has the same memory model as ESP32 but has cut the Ethernet and Bluetooth parts, so only Wi-Fi connection is possible – same as ESP8266, but offers more power, secure boot and encrypted firmware. Also support of decent SSL connection, something which lacks in ESP8266."

"Our ESP32-S2-DevKit-Lipo is pin to pin compatible with [Espressif's] ESP32-S2-Saola-1. To keep compatibility with SAOLA-1 we add RGB LED, but also add LiPo battery charger and ESP32-S2-DevKit-Lipo can operate even without external power supply only on LiPo battery, there is battery level monitoring and external power supply sense. ESP32-S2-DevKit-Lipo can power external circuits with 3.3V up to 200mA when operate on battery."

For projects which don't need the RGB LED - which appeared, Olimex found, to draw considerable current even when switched "off" but enabled on the board — a header is provided, and when disabled via header the overall power draw is as low as possible — under 30µA in deep sleep mode, the company claims."

Olimex has a prediction for the future of the ESP32-S2 family, too: "Price-wise now S2 is a bit lower cost than ESP32 and more expensive than ESP8266," the company notes, "but there is very strong competition in this niche coming from the new Bouffalo BL6XX chips, so my prediction is that to stay ahead Espressif will further lower the prices of ESP32-S2 to match ESP8266 very soon."

The open hardware ESP32-S2-DevKit-Lipo is now available from Olimex's store, priced at €5.56 (around $6.53); a WROVER-based version, priced at €6.36 (around $7.47), offers an increased 2MB of pseudo-static RAM (PSRAM).