BC127 connection to a wired headset

IoT Modules
1

Hello all,
I understand that the BC127 can be directly connected to a microphone and 32ohm speakers.
I wish to connect the BC127 to a wired headset, using a 4-contacts 3.5mm PL audio jack with the following pinout:
1- TIP (Right Speaker Out)
2- Ring1 (Left Speaker Out)
3- Ring 2 (Common GND for both speakers and microphone)
4- Sleeve (Microphone in)

First question - Microphone connection:
There is an example how to connect a single microphone to the module:

mic
mic1173×805 129 KB

Is it possible to connect the microphone to both LP/LN and RP/RN inputs? (marked in red lines)

Second question - Speaker outputs:
As mentioned, the speaker connection is a single ended type (both left and right are referenced to GND)
With no use of an external audio amplifier, What is the correct way of connecting both speakers in a single ended configuration?
Is this the right way?

spkr
spkr1194×873 201 KB

Thanks!
Nir

2

@nir76

So answers as far as I Know.

  • Q1 – Yes you should be able to do that but why?
  • Q2 – Normally you would run the speaker from the positive to ground and leave the negative floating.

Regards

Matt

3

Hi Matt,
1- If the microphone is connected only on the left channel, will the RX module produce only the left speaker signal or both left and right? if mic LP/LN in mono mode is connected internally to RP/RN by software so yes, it is not necessary, but is it really so?
2- Ok, understood.
Thanks for your reply
Nir

4

@nir76

So the short answer is that if you connect one mic then that will be the audio that is transmitted, whether that is stereo or not depends on the BT profile being used.

Regards

Matt

5

OK, Thanks for your reply
Best Reards,
Nir