It's a custom PCB that I made, it's connected via I2C to MC3419 (accelerometer) and MAX17055 (battery fuel gauge). Then with "PWM" it's connected to AL1783 (led driver), and with a mosfet for running ...

Some boards (like the Arduino Nano), cannot supply enough current for the SX127x in TX mode. This will cause lockups when sending, be sure to use an external 3.3V supply that can provide at least ...

In the old days, a serial port often connected to an acoustic coupler that gripped a phone handset and allowed a remote connection to a far away serial port (via another phone and acoustic coupler) at ...