SainSmart WiFi Shield V2.0 for Arduino, 802.11b Wi-Fi Certified, WEP (64-bit and 128-bit), WPA/WPA2 (TKIP and AES) PSK
Mega 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 Mega wont charge battery; if it is not, the external battery will be charged. We bring comparator to check the operating current of Cuhead Mega so you know it is Arduino giving power to Mega or the opposite way, and change the charging circuit to connect/disconnect based on that.When UNO connect Arduino, there are two working status：1) Connect Arduino with USB/Adaptor , Arduino gives power to UNO, the charging circuit on UNO will disconnect；2) No external power for Arduino, then the charging circuit of UNO is working, and the battery will power the boards. Normally we give power to Arduino directly, thus the charging circuit is inactive.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.Wi-Fi Transceiver Module FeaturesIEEE Std. 802.11-compliant RF TransceiverSerialized unique MAC addressData Rate: 1 and 2 MbpsIEEE Std. 802.11b/g/n compatibleIntegrated PCB antenna (MRF24WB0MA)Range: up to 400m (1300 ft.)Single operating voltage: 2.7V-3.6V (3.3V typical)Wi-Fi Transceiver Module RF/Analog FeaturesISM Band 2.400-2.484 GHz operation14 Channels selectable individually or domain-restrictedDSSS ModulationMega 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