WiFi Module - ESP8266 (Olimex)

Description: ESP8266 is very highly integrated SOC which includes Xtensa LX106 core processor, RAM, RF front end and allow WIFI TCP-IP stack to be implemented on board with just few components beside ESP8266. It's very new but promising IC and it attracted a lot of attention with its launch.

MOD-WIFI-ESP8266 is small board with an integrated antenna and UEXT connector and allows ESP8266 to be easily connected to all Olimex boards via the UEXT connector thus adding WIFI capabilities.

MOD-WIDI-ESP8266 is UEXT module with the famous ESP8266 UART to WIFI IC. This module allows all our development boards with UEXT connector to have access to WIFI via simple AT command set. Our module comes with installed 2MB of SPI Flash while our competitors modules have just 512KB of SPI Flash.

The idea of  MOD-WIFI-ESP8266 is to use it as an easy hardware expansion of existing Olimex boards. That is why it has UEXT connector. You plug it in another board with UEXT connector and the hardware connections are complete. It is visible in the schematics that MOD-WIFI-ESP8266 uses only first 4 pins of the UEXT – #1 (3.3 Vcc), #2 (GND), #3 (RXD), #4 (TXD). This means only a data UART interface is available. The rest of the pins of the chip are not routed for easier access - if you need more signals consider MOD-WIFI-ESP8266-DEV or ESP8266-EVB.  To update the firmware of the board you would need to change the position of the SMT jumpers.

Features:

• 802.11 b / g / n
• Wi-Fi Direct (P2P), soft-AP
• Built-in TCP / IP protocol stack
• Built-in TR switch, balun, LNA, power amplifier and matching network
• Built-in PLL, voltage regulator and power management components
• 802.11b mode + 19.5dBm output power
• Built-in temperature sensor
• Off leakage current is less than 10uA
• Built-in low-power 32-bit CPU: can double as an application processor
• UART
• A-MPDU, A-MSDU aggregation and the 0.4 Within wake 2ms, connect and transfer data packets
• standby power consumption of less than 1.0mW (DTIM3)

Documents:

• ESP8266 English datasheet
• How to change the modes (FLASH, UART, SDIO)
• ESP8266 community wiki
• ESP8266 vendor wiki

Hardware:

• Board's schematic (PDF)
• Hardware sources (CadSoft EAGLE)
• Resources

Software:

• Arduino client example
• Arduino server example
• Firmware updater
• ESP8266 software downloads and official SDK
• ESP8266 GPIO registers

FAQ

How do I send AT commands to the board?
The board's jumpers has to be in default FLASH mode. You would either need to use a cable that can power targets, or split the GND line. The reason is that the power supply needs a GND line and the cable needs a GND line but the board has only a single GND on the connector (UEXT pin #2). You can use MOD-USB-RS232 for easy connection to a personal computer (you would need to change the jumpers of MOD-USB-RS232 to be able to power the MOD-WIFI-ESP8266 and to communicate with it; once this is done it becomes a plug-and-play setup)

I send basic AT commands to the board but I receive only "ERROR" response. What is the problem?
The commands are case sensitive. Make sure you are using capital letters.