DESCRIPTION:

• LoRa32u4 II is a light and low consumption board based on the Atmega32u4 and HPD13 915MHz LoRA module and an USB battery charging circuit.
• Ideal for creating long range wireless networks that can exceed 2.4 GHz 802.15.4 and similar, it is more flexible than Blue-tooth LE, does not require high power unlike WiFi and offers long range.
• ATmega32u4 @ 8MHz with 3.3V logic/power
• 3.3V regulator with 500mA peak current output
• USB native support, comes with USB bootloader and serial port debugging
• Built in 100mA lipoly charger with charging status indicato LED
• Reset button

HPD13:

• Receive current: 10 ~ 14mA
• Interface Type: SPI
• Operating temperature: -40 ° C to + 85 ° C
• Digital RSSI function
• Automatic frequency correction
• Automatic gain control
• Radio wake-up function
• Low voltage detection and temperature sensor
• Fast wakeup with frequency hopping
• Highly configurable packet handlers

LOW POWER:

• The battery monitoring circuit is now active and enabled by the previously unused pin PB0 (not broken-out on headers), it must be enabled (high) to allow battery monitoring.
• The battery charger is now controlled, it must be enabled (high) by PB0 to allow battery charging.
• The LDO has been replaced for an ultra low IQ LDO (0.5uA).
• Overall sleep current has been lowered from 260.2uA to 183.8uA (tested with Atmega32u4 in watchdog sleep mode @ 8MHz and LoRa circuit in sleep mode).

USAGE:

• LoRa DIO1 is now connected by default to Atmega32u4 pin 5 (PC6) allowing direct use of LMIC and other LoRaWAN libraries without soldering, it is still possible to disable this link by opening the DIO1 solder jumper on topside.
• LoRa DIO2 and DIO3 are now routing to Atmega32u4 pin 6 (PD7) and 14 (PD5), solder jumpers are open by default (these DIO pins are rarely used).
• Atmega32u4 pins 0 (PD2),1 (PD3) for UART and 2 (PD1), 3 (PD0) for I2C are now free for use.
• LoRa DIO pins solder jumpers have been moved on topside for better accessibility.
• Pull-up resistors (4.7K) have been added on the I2C bus.
• The antenna uFL connector has been moved on topside to ease access.