Relationship between channels and frequency/SF?

I have a few basic question on setting the channel.
I am using firmware-tbeam-US-0.7.11.bin
and android 0.7.93

Can the lora frequency be set (I assume it is currently fixed 915MHz on the US firmware) ?
This would be to allow multiple channels frequencies, in-addition to the channel name.

Does the channel options set a Spread Factor ?
Do all devices display what freq and channel option (mode) they are set to ?

I have a follow-on question … concerning what frequency does the country builds
actually specify.

In the master it has various supported hardware depending on what
country. This leads to a selection of which compiled firmware to choose based on
several supported countries.

This maybe follows the

Then the code in
seems sort of related. It defines variables such as define CH0, CH_SPACING, NUM_CHANNELS


  1. Does the device start using frequency CH0 ? (example for US 903.08f // MHz )
  2. Does changing the android “channel name” (from default) change the frequency to the next frequency “channel” ? (example US 903.08 + 2.16 = 905.24 MHz )
  3. Is the frequency “channel” related or unrelated to the android “channel” ?

I saw a post somewhere … but can’t find it… about changing the android channel name to append it to reflect the actual frequency/mode…

I get lost trying to follow the flow of the various variables.

EDIT: changed the links…