You can change UART pin assign. If you define ON_THREAD_MODE, you can use the UART two channels even available hardware channel is only one.

Fork of BLE_I2C_pin_assign by Kenji Arai

Revision:
1:f3511dc0569f
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mbed-os.lib	Fri Sep 01 08:58:49 2017 +0000
@@ -0,0 +1,1 @@
+https://github.com/ARMmbed/mbed-os/#98ba8acb83cfc65f30a8a0771a27c71443ab093a