Precise details:
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:
①– Type:
Dev-Board – Can be used directly;
Module – Only core function, need to cooperate with external PCB or circuit.
② – Lithium: All lithium battery socket for Heltec boards is SH1.25-2;
③ – Vext: 3.3V(500mA) output, for external devices (e.g. sensors) power supply, in deep sleep mode, Vext can be shut down via software;
④ – 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 user’s 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.
Source |
Parameter |
MCU |
STM32L151CBU6 (Ultra-low-power 32-bit MCU ARM®-based Cortex®-M3) |
LoRa chip |
SX1278 |
LoRa bands |
EU_433, CN_470_510,two bands optional |
LoRa maximum output power |
18dB ± 1dB |
Hardware Resource |
USART x 3; SPI x 2; I2C x 2; ; USB 2.0 x 1 |
12 – bits ADC; 12 – bits DAC |
DMA controller |
28 general GPIO |
Flash |
128KB FLASH;16KB SRAM;4KB EEPROM;80B BACKUP REGISTER |
Interface |
Micro USB x 1; LoRa antenna(IPEX) x 1 |
length x width x height(pin) |
57 x 27 x 7(14) mm |
Battery type |
Lithium |
Low power design |
Deep Sleep: 6uA |
Electrical characteristics |
Condition |
Minimum |
Typical |
Maximum |
Power Supply |
USB powered(≥500mA) |
4.7V |
5V |
6V |
Lithium powered(≥250mA) |
3.3V |
3.6V |
4.2V |
3.3V(pin)powered(≥150mA) |
2.7V |
3.3V |
3.5V |
5V(pin)powered(≥500mA) |
4.7V |
5V |
6V |
Power consumption(mA) |
LoRa 10dB emission |
|
50mA |
|
LoRa 12dB emission |
|
60mA |
|
LoRa 15dB emission |
|
110mA |
|
LoRa 20dB emission |
|
130mA |
|
Output |
3.3V pin output |
|
|
500mA |
5V pin output (USB powered only) |
|
Equal to the input current |
|
External device power control (Vext 3.3V) |
|
|
350mA |
Package includes:
1 x STM32L151CBU6 Development Board
LoRa Kit 151 Example Code:
LoRa Kit 151 Schematic diagram:
Summary of Common Problems: