UART Interface
Users should wait at least 1 second after resetting before using the UART API interface. The UART can operate in a binary or a shell mode. After reset for the UART, The default mode can be configured by leaps_serial_cfg_set. Press “ENTER” twice within one second to switch from binary mode to shell mode. Use shell command quit to switch from shell mode to binary mode.
Example leaps_gpio_cfg_output
Wakeup via UART
If the module sleeps (in low-power mode), the wakeup procedure has to be executed before SPI/UART starts accepting commands. At least, 35 microsecond wide pulse has to be generated on the CS pin of the SPI or at least one byte has to be sent on the UART interface to wake up from the sleep (only in low-power mode).