TTGO 915MHz Shield ESP32 WiFi Bluetooth 18560 Battery Holder Solar Charging Module Development Board, 915MHz Shield

Product Description Hardware Specifications:
1. Main chip: ESP32
2. Module: ESP32-WROVER-B, 915MHz Shield
3. Interface: USB, SD card, solar input interface
4. Flash memory: 4m flash / 8m PSRAM
5. Button: reset, power switch
6. USB to TTL: CP2104
7. Clock speed: 40 MHz
8. SIM card size: NANO SIM card
9. SIM antenna
10. GPS antenna.
11. Operating temperature range: -40-85 degrees
12. Product Dimensions: 111mm x 37mm x 20mm
13. Product weight: 50g

Power Specifications:
1. Working voltage: 5V input
2.Solar input voltage range ???4.4-6V
3. Working current: about 200mA
4. Charging current: 780 mA
5. Battery model: 18650
6. Battery holder model: 18650 battery holder
7. JST connector: 2pin 2mm
8. USB: Type-C 3.0

Wifi:
1. Standard: FCC / CE-RED / IC / TELEC / KCC / SRRC / NCC
2. Protocol: 802.11 B/g/N (802.11n ??? speed up to 100 mbps) A-MPDU and A-MSDU polymerization ??? Support Protection interval 0.4?
3. Frequency: range 2.4 GHz ~ 2.5 GHz (2400m ~ 2483.5m)
4. Transmit power: 22DBM
5. Communication distance: 300m

Bluetooth:
1. Bluetooth Meet Protocol: V4.2BR/EDR and BLE Standard
2. Radio Frequency: with -97DBM Sensitivity NZIF Receiver Class-1, Class-2 and Class-3 Emit AFH
3. Audio frequency: CVSD and SBC audio frequency

Software Specification:
1. Wi-Fi Mode: Station / SoftAp / SoftAp + Station / P2P
2. Security mechanism: WPA / WPA2 / WPA2-Enterprise / WPS
3. Encryption type: AES / RSA / ECC / SHA
4. Firmware Update: Download UART/OTA ??? via network/host to download and write firmware ???
5. Software development: Support cloud server development / SDK for user firmware development
6. Network Protocol: IPv4, IPv6, SSL, TCP/UDP/HTTP/FTP/MQTT
7. User configuration: AT+ instruction set, cloud server, Android/iOS app
8. OS: Freertos

Version update function:
1. The positive and negative poles of the battery are connected to the wrong protection, overcharge and discharge protection
2. GPS power control, reduce power consumption, reaches lowest 300ua when sleeping
3. Replacing ordinary charging IC with solar charging IC