PCM2912: intend to use with PTT ( push to talk)

Hi Dominick,

Just to clarify, the PCM2912 is not recommended for new designs. The PCM2912A is the successor that you should be considering.

The PCM2912A does have a microphone mute pin (Pin 30) that you could use as a PTT. In fact the PCM2912A EVM takes advantage of this pin to create a PTT feature.

Best regards,

Jeff McPherson

HI Jeff,

Yes PCM2912A that's what I meant to say thanks you . As far as the PTT I don't believe the Mic mute  function helps since you want to interrupt  the audio from the transmitter not the Mic in from you? Or did miss something?

again thanks for your reply

Dominick

HI Jeff,

Just to clarify : I am saying PTT is half duplex transmit which means Microphone is enabled, so the mute function can not be used for PTT

I can stop audio out to form the speaker but that does not change the transmission to half duplex.

Again thanks  for your input please reply as soon as you can.

Dominick

HI 

please reply to my latest  blog

Hi Dominick,

Sorry for the wait. You're correct that the mute button alone doesn't create a fully functioning half duplex system. The mute button only disables the mic input and has no effect on playback. We don't support half duplex internally so you'll have to create the functionality externally. You can do this either by taking advantage of the USB controller and using Windows OS for example like it's a sound device, disabling and enabling the recording and playback paths when needed. However that's pretty niche and if you need something more flexible/general I can help you find a codec with an i2c interface that will let you use an external controller to create the PTT function you're looking for.

Thank you,

Jeff McPherson 

HI Jeff,

Thanks for your reply , what I was thinking is to use my Micro to accommodate the PTT function with audio Codec with USB with either I2C  or UART to do  the PTT , do you have some suggestion on the USB codec that will do this?? 

Again thank for your support

Hi Dominick,

The challenge is that our USB codecs don't include a serial interface like I2C to do the configuration. It was designed with the assumption that the USB protocol would handle that. Admittedly I'm no expert in USB protocol but virtually every other codec we have uses an I2C interface to configure the device, which is much simpler in my opinion. Maybe your microcontroller would be a better place to drive the USB connectivity that you need instead of the codec, since the controller could receive the digital audio data from and to the codec to manage the half-duplex data stream. You could look into a codec like the TLV320AIC3206. I chose this one because of the stereo record/playback, both headphone and lineout drivers, and a relatively lower cost in our catalog. You can find the rest of our codecs here if you need something else: https://www.ti.com/audio-ic/converters/codec/products.html#p1020=2;2&p1345=2;8

Best regards,

Jeff McPherson

Hi Jeff,

Thanks for you reply I agree with your input I will use my controller with USB and communicate  data from the  Audio Codec IC  and add the PTT circuit to the micro.

What's the best way to (bus wise) to communicate audio data from the codec ?I2C would be too slow I2S is Ideal but the micro would have to handle the bus? any thoughts on this?

Again thanks for your input to this design! 

HI Jeff,

Yes agree with your  the response It helps I am still trying to figure out which was is the best.  I like the idea of  Micro and codec IC  I will talk to FW guy see what's best.

Ok if I run the block diagram by you once complete?

Thanks,

Dominick