Please help explain unknown beeping noises from BNF nazgul evoque 2

Question

I'm completely new to hobby, badly missing some know-how. I've got here BNF nazgul evoque 2. I just plugged battery in to do first setup, and I cannot identify what does it 'beep about'. I found this link-about-arming-issues, but this is NOT arming issue, and these beeps just don't sound like this(I can hear 3 different beep lengths).

Scenario 1: Note that drone just got out of box, got fresh battery, never flew, never undergo any out-from-factory configuration. Drone is happily(?) sitting on desk, while I'm configuring home network, and after some time it start beeping. Beeping 1. Beeping 2. Why? What is it?

Scenario 2: Ok, but lets get some 'real action'. I started radio, I plugged battery to drone. Both are connected via binding phrase. All silent. Then I arm. And then this sound. What is it? Radio is connected, I could arm, it seems I could take away, if I had props. What's wrong?

If you know, please explain. If you have link to documentation, where beeping is explained (including this one), please share.

Thanks!

Beeper configuration in betaflight(all was enabled from factory, but I took the liberty to turn some off):

Answer 1

Answers:

• beeping 1: could be that ACC was not calibrated, seems most close, but it's probably not that. ACC calibration are 2 short beeps, but I'd expect them to be uniformly distant from each other, since this is defined as 50ms beep, 50ms delay, 50ms beep, 50 delay, end.

• beeping 2: no idea, definitely not one of named warnings, definitely not confirmation nor warning beeps. Might be gps beeping, I cannot read that code. No idea what that is.

• is there a list of beeping codes: Probably no. There is this link and then there is source code with more named beeps, and custom functions for gps, confirmation beeps(pseudo: confirmation(N): 20ms beeps with 200ms spacing, repeat (N/2)-times) and warning beeps (pseudo: warning(N) 1. 5 flash beeps 50s/500ms (the question is if it sounds since I believe this is function which is called by arm prevention alarms), followed by 2. N/5 long beeps 3. N%5 short beeps). But there is NO unifying rule for these beeps, and beeps and delays are chosen ± arbitrarily or I cannot understand the rule. The great opportunity to use morse code, or at least some unified scheme wasn't used and that's why there won't be complete list, since you cannot fix it now for backward compatibility/user base reasons.

• beeping in scenario 2 mode: this is rc_smoothing_init_fail. radiomaster boxer (for some reason) came with packet rate F1000 as default and same was set on rx, and hw on quad cannot handle that. Updating to 250hz fixed this completely.