Connecting remote radio nodes to a distant server, with no wired infrastructure — that’s what this gateway is built for.
On one side, a 868 MHz radio interface handles links with multiple remote nodes. On the other, a cellular modem (4G primary, 2G fallback) forwards the data to the outside world. The STM32L152 supervises communication, power management, and overall system behavior.
Power comes from a battery combined with a solar panel, which means energy management is directly tied to communication strategy. In standby, you conserve. When it’s time to transmit, you spend. Finding the right balance between those two modes in real field conditions — that’s where the design actually gets interesting.