[Updated: Sept. 20] — Itead has launched a $2.10, 14 x 13.5mm “PSF-A85” WiFi module based on the ESP8285 SoC, a version of the ESP8266 that adds 1MB SPI flash.
In recent months, before releasing the faster, Bluetooth enabled ESP32 big brother to its popular ESP8266 WiFi SoC, China-based Espressif released a follow-on to the ESP8266 called the ESP8285. Now, Itead, which also makes various Sonoff-branded WiFi-enabled IoT gizmos, has released what appears to be the first third-party WiFi module based on the chip: the $2.10 (without antenna) PSF-A85.
Additionally, a more comprehensive $20 “ESP8285 Development Board” from Pesky Products, that’s programmable via the Arduino IDE, is emerging at Tindie.com (see farther below).
Espressif ESP8285 SoC
Announced by Espressif back in March, the ESP8285 is nearly identical to its predecessor, being based on an “enhanced” version of Tensilica’s L106 MCU, clocked at the same 80MHz. However, while the ESP8266 has no internal flash, the ESP8285 includes 1MB of built-in SPI flash, making it suitable for tinier WiFi-enabled device applications, including wearables such as smartwatches, smart glasses, activity monitors, and smart bracelets.
Espressif ESP8285 block diagram
(click image to enlarge)
Like the ESP8266 and ESP32, the ESP8285 can be used as a standalone processor running an RTOS such as FreeRTOS, or as a companion to another MCU-based system, such as an Arduino. (More information may be found in this Espressif ESP8285 data sheet (PDF).)
Itead PSF-A85 module
Itead’s tiny PSF-A85 module measures 14 x 13.5mm and weighs only 1 gram. The module’s applications are expected to include wearables, smart power grid, smart transportation, smart home, handheld devices, and industrial control.
The PSF-A85 extends the ESP8285 SoC with various WiFi radio functions and connections, including serial transparent transmission, PWM and GPIO controls, and “good transmission performance,” says Itead. PWM controls, for example, let you adjust lighting, including LED color, or adjust motor controls. GPIO controls can control switches, relays, and other components.
The device supports WiFi ST mode, for remote mobile phone or computer access via the Internet, or AP mode, which turns it into a directly accessible WiFi hotspot. There’s also an STA+AP mode that lets you switch between the modes via the Internet. The PSF-A85 supports either antenna or IPEX connectors.
Other features and specifications for the PSF-A85 include:
- 2.4GHz 802.11 b/g/n/d/e/i/k/r
- STA/AP/STA+AP mode support
- Wi-Fi Direct (P2P) support
- WPA/WPA2 PSK and WP security
- Supports MIMO 1×1 and 2×1, STBC, A- MPDU and A-MSDU aggregation and 0.4μs guard interval
- WMM power save U-APSD
- Multiple queue management to fully utilize traffic prioritization defined by 802.11e standard.
- Adaptive rate fallback algorithm for setting the optimum transmission rate and Tx power based on actual SNR and packet loss info
- TCP/IP protocol stack, with multi-way TCP client support
- Rich Socket AT command support
- UART/GPIO data communication support
- 3.3V power supply
Pesky Products ESP8285 Development Board
Pesky Products has designed a 25 x 18mm development board, based on the ESP8285, that’s programmable over USB using the Arduino IDE. The board includes a USB-to-serial chip and provides a USB Micro-B connector for convenient access by a host PC, Also included are a single-cell LiPo battery charger, reset and boot buttons, and five status LEDs.
ESP8285 Development Board top and bottom views
(click images to enlarge)
The development board exposes all 11 of the ESP8285’s GPIOs, and provides connection points around its periphery for power and control of sensors, motor drivers, and other external functions that can managed by the ESP8285. Adding sensors for pressure, temperature, humidity, and light can turn the ESP8285 Development Board into “an environmental monitor with sensor values streaming to a web page via wifi,” says the board’s product page. The sensors are available for an extra $10.
ESP8285 Development Board PCB layout
(click image to enlarge)
The board’s PCB design includes “a through-hole at the end of the antenna trace where a 1.25 inch long copper wire needs to be soldered for ‘good enough’ wifi transmission/reception,” adds “onehorse” of Pesky Products. “With this method I have no trouble receiving signals from ESP8266 devices placed around the house from anywhere inside the house.”
The ESP8285 Development Board’s design is open hardware. Schematics and a PCB layout image are available now for download from the board’s Tindie.com page, and the full design will be available for download from OSH Park’s “shared space.”
Additional details on the Pesky Products ESP8285 Development Board are available at its Tindie.com page. The board is in stock now, with single-piece pricing listed as $19.95 (plus shipping).
— with additional reporting by Rick Lehrbaum, and a thank you to “Harley” for alerting us to the PSF-A85