The Espressif Systems ESP8684-MINI Small 2.4 GHz Wi-Fi® and BLUETOOTH® 5 Modules offer an onboard PCB antenna or external antenna connector and are based on the ESP8684 series of SoCs with a 32-bit RISC-V single-core microprocessor, operating at up to 120 MHz. The devices also provide a rich set of peripherals, ideal for smart homes, industrial automation, healthcare, and consumer electronics applications where wireless connectivity is required.
These modules are available in three variants that integrate the ESP8684H1, ESP8684H2, and ESP8684H4 chips, I would think corresponding to the 1 MB/2 MB/4 MB SPI flash options stated in most of their documentation. This SoC also has on-chip memory (576 KB ROM, 272 KB SRAM (16KB for cache)) and supports flash in-circuit programming.
In terms of Wi-Fi and Bluetooth capability, Espressif’s dual solution is IEEE 802.11 b/g/n-compliant and supports 20 MHz bandwidth in the 2.4 GHz band. There is also simultaneous support for infrastructure BSS in Station mode, SoftAP mode, Station + SoftAP mode, and promiscuous mode. The internal antenna is built for co-existence between Wi-Fi and Bluetooth LE 5, the latter of which supports a high-power mode (20 dBm) and speeds of 125 kbps, 500 kbps, 1 Mbps, and 2 Mbps. With low power in mind, the chip has a 3.0 V to 3.6 V operating voltage, and the -40°C to 105°C operating ambient temperature makes it suitable for use in many environments. The Wi-Fi operation also supports an external amplifier if required.
To evaluate this chip, Espressif created the ESP8684-DevKitM-1 development board, which is stated as ‘entry-level’, but I would not think that enough of a reason to cast the technology aside – Please let us know if you would like to evaluate any other Espressif products; I simply chose this one due to its compact size. Most of the I/O pins are broken out to the pin headers on both sides of this board for easy interfacing. Developers can either connect peripherals with jumper wires or mount the ESP8684-DevKitM-1 on a breadboard. There are three mutually exclusive ways to provide power to the board: Micro-USB Port recommended), 5V and G (GND) pins, or 3V3 and G (GND) pins.
(All images sourced from Espressif)