Heltec LoRa Node Products Difference Table:

Heltec LoRa product family already included follow options:LoRa spread spectrum communication (node);Battery powered;Good RF circuit design and impedance matching.

Notes: Type:Dev-Board Can be used directly;Module Only core function, need to cooperate with external PCB or circuit. Lithium: All lithium battery socket for Heltec boards is SH1.25-2; Vext: 3.3V(500mA) output, for external devices (e.g. sensors) power supply, in deep sleep mode, Vext can be shut down via software; Low Power: Products low power design, of Whole Circuit, the measured data are the current of the system during deep sleep.
Feature:

-In order to meet the users requirements for Ultra-Low-Power and standard LoRaWAN protocol, we designed this product. On the basis of STM32L151CBU6MCU and SX1278 LoRa chip(433, 470MHz), the low power current can reach to 6uA.
-CE Certificate;-Microprocessor: STM32L151CBU6 (Ultra-low-power ARM Cortex-M3 MCU with 128 Kbytes Flash), with LoRa node chip SX1278 (433MHz ~ 510MHz);-Micro USB interface with a complete voltage regulator, ESD protection, short circuit protection, and other protection measures;-Onboard SH1.25-2 battery interface, integrated lithium battery interface, integrated battery management system (battery power detection, USB / battery power automatic switching);-Integrated CP2102 USB to serial port chip, convenient for program downloading, debugging information printing;-This product supports DFU mode download (need to cooperate with relevant download software).-System resource: FLASH 128K,RAM 16K,EEPROM 4K;-User available resources: FLASH 64K, RAM 8K, EEPROM 4K;-Provide standard LoRaWAN protocol routines.-With good RF circuit design and basic low-power design (sleep current 7uA), it is convenient for IoT application vendors to quickly verify-LoRaWAN protocol easily.

Package includes:

1 xSTM32L151CBU6 Development Board

LoRa Kit 151 Example Code:LoRa Kit 151 Pingpang test example code (need two LoRa Kit 151 to test): https://heltec.org/wp-content/uploads/2019/07/Kit_151_PingPang.zipLoRa Kit 151 Schematic diagram:https://docs.heltec.cn/download/LoRa_Kit_151_sch_diagram.PDFSummary of Common Problems:http://www.heltec.cn/summary-of-common-problems-in-wifi-kit-series-continuous-update/?lang=en