When it comes to reliable radio communication independent of wireless networks, this is it LoRa standard a good choice, it also enables reliable communication over a few hundred meters. The module, which is only about 12 × 12mm in size LoRa-E5 Seeedstudio has manufactured according to industry standards, it integrates one SX126x radio chip from Semtech and the 48MHz fast ARM processor STM32WLE5JC from ST Micro with extremely energy-saving ARM Cortex-M4 core. The module consumes less than 7mA in receiver mode, and only 2.1µA in pauses. When transmitting, short current peaks of up to 110mA can occur at maximum power.
In addition to LoRa, the STM32WLE5 also masters the GFSK, GMSK and BPSK modulation types. 3 UARTs, I2C, an ADC channel with 12 bits, SPI and six universal port pins are brought out as I / O. The Chinese manufacturer emphasizes that the module is certified according to FCC and CE (EU868 / US915). It is supplied with AT command firmware; If you have an STM32cube programmer, you can also develop your own programs using the STM32 toolchain. As usual with Seeedstudio, there is good documentation and code examples, here in the form of your own LoRa E5 wikis. The module is available for immediate delivery and costs $ 9.90.