In order to test if your hardware is connected the right way, you can use following HM-10 test program. It will check the connections, check the baudrate, show all kinds of information about the BLE module and set the notification OFF. Do not use the original code by JP Liew because this sets the notification ON.
I guess that, for running it on Particle Photon, you’ll have to define the connection like this:
#define SERIAL_BLE Serial1
and uncomment the SoftwareSerial stuff.