FOBO tire pressure monitoring system report..

[GoldOxide_imp]

Just a guess and knowing zero about the sensor module implementation: To conserve sensor battery, the bluetooth transmission from the sensors is probably at a period and data rate that is as slow as possible without being too much of an annoyance. Initial on-demand requests probably wakes-up resources on the devices and takes readings. This could take some time. Subsequent reading requests might be faster as the device is fully active/awake. Every request and event consumes device battery, so beware. The app just leverages the bluetooth transceiver (mobile phone), and interprets the sensor raw data and presents it to the user (tire pressure).