CuHead WiFi Shield for Arduino V2.0

Introduction

This document is to introduce Cuhead WiFi Shield V2.0（hereafter we call Cuhead V2.0).

Cuhead V2.0 use low consumption MRF24WB0MA embedded Wi-Fi Transceiver Module，match 2.4 GHz IEEE 802.11b™ RF Standard.

Cuhead V2.0 adopt standard Arduino laminated design . It is designed to plug on Arduino Diecimila/Duemilanove/Uno etc.

Features

Standard spec

Cuhead V2.0 has charging and discharging function, the charging circuit is used to tell voltage of the battery.

We can connect the positive and negtive of the battery to BAT, if the battery is full, then Cuhead V2.0 wont charge battery; if it is not, the external battery will be charged.

We bring comparator to check the operating current of Cuhead V2.0 so you know it is Arduino giving power to Cuhead V2.0 or the opposite way, and change the charging circuit to connect/disconnect based on that.

When Cuhead V2.0 connect Arduino, there are two working status：

• Connect Arduino with USB/Adaptor , Arduino gives power to Cuhead V2.0, the charging circuit on Cuhead V2.0 will disconnect；

• No external power for Arduino, then the charging circuit of Cuhead V2.0 is working, and the battery will power the boards. Normally we give power to Arduino directly, thus the charging circuit is inactive.

Add Potentiometer

The new added potentiometer is to adjust the voltage to any value needed (by adjust AMS1117 Vin to 5.6V~6.0V).

It is hard to do so by fixed resistance. The default voltage of Cuhead V2.0 has been set in the right voltage，normally you don't have to adjust it.

Increase the Flash memory chip

The increase of the Flash memory chip is serial interface of the Flash memory chip, it can work in 2.5 V-2.7 V, can be used as program code data storage. Flash memory chip and Arduino are used together SPI interface, the speed can be up to 66 MHz. It contains 17301504 bytes, is organized for 4096 page, each page 512 or 528 bytes. In addition to main memory, the Flash memory chip also includes two SRAM data buffer, each buffer 512/528 bytes. When main memory is programming, buffer is allowed to receive the data, and to support data stream write. And the Flash memory chip allow simple in the system to programming, without having to input high programming voltage. It can through the # CS Enable, and through the three line interface (SI, SO, SCK) in data communication.

Because Cuhead V2.0 Flash memory chip and Arduino uses the same SPI interface, we through the Cuhead V2.0 module of the flash_sn jump line to select is public SS or CS. The flash_sn connect 1, 2 pin is SS, connect 2,3 pins for CS.

When Cuhead V2.0 need to use Wi-Fi choose SS, make Flash is invalid, so Wi-Fi can accurately to receive information, and deal with the IP protocol. If this time not banned Flash, data through the SPI send come over, Flash and Arduino will receive the data and have the conflict.

Wi-Fi Transceiver Module Features

• IEEE Std. 802.11-compliant RF Transceiver
• Serialized unique MAC address
• Data Rate: 1 and 2 Mbps
• IEEE Std. 802.11b/g/n compatible
• Small size: 21mm x 31mm 36-pin Surface Mount Module
• Integrated PCB antenna (MRF24WB0MA)
• Range: up to 400m (1300 ft.)
• Single operating voltage: 2.7V–3.6V (3.3V typical)
• Simple, four-wire SPI interface with interrupt
• Low-current consumption:
• RX mode – 85 mA (typical)
• TX mode – 154 mA (+10 dBm typic
• Sleep – 250 µA (typical)
• Hibernate – <0.1 µA (typical)

Wi-Fi Transceiver Module RF/Analog Features

• ISM Band 2.400–2.484 GHz operation
• 14 Channels selectable individually or domain-restricted
• DSSS Modulation
• Data Rate – 1000 kbps
• -91 dBm Typical sensitivity at 1 Mbps
• +10 dBm Typical output power with control
• Integrated low phase noise VCO, RF frequency synthesizer, PLL loop filter and PA
• Digital VCO and filter calibration
• Integrated RSSI ADC and I/Q DACs, RSSI readings available to host
• Balanced receiver and transmitter characteristics for low power consumption

Cuhead V2.0 MAC/Baseband Features

• Hardware CSMA/CA acce ss control, automatic ACK, and FCS creation and checking
• Automatic MAC packet retransmit
• Hardware Security Engine for AES and RC4-based ciphers
• Supports 802.1x, 802.1i
• Security: WEP, WPA-PSK, and WPA-2-PSK

FAQ

• Question:

I have your Cuhead module,but when i connect it with my Arduino Mega 2560,it is not working.what can i do now?

• Answer:

Please check the connections with the arduino board carefully,it is different with different arduino boards. For example,Arduino Mega uses different pins for the SPI interface than the previous boards, so you may not able to use the headers to stack the shield onto the Mega,and you may have to pull pins to match the correct SPI pins to get it working.

Support

If you have questions or other better design ideas, you can go to our forum to discuss or creat a ticket for your issue at linksprite support.

See Also

Other related products and resources.

Licensing

This documentation is licensed under the Creative Commons Attribution-ShareAlike License 3.0 Source code and libraries are licensed under GPL/LGPL, see source code files for details.