# How to configuration to using PCM in IOT#0? **URL:** \ **Category:** IoT Cards\ **Created:** [July 7, 2016, 3:25pm UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143 "2016-07-07T15:25:42Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![toanmh](https://avatars.discourse-cdn.com/v4/letter/t/48db29/32.png) [@toanmh](https://mangoh.discourse.group/u/toanmh)\ **Post date:** [July 7, 2016, 3:25pm UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/1 "2016-07-07T15:25:42Z")
I can not see any documents talking about this? Can you help me? Thanks ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [July 7, 2016, 7:24pm UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/2 "2016-07-07T19:24:18Z")
Hi, Are you asking how to direct PCM to IoT#0 and not to audio codec? If so, you can do that using the mux control tool. Please follow the instructions on how to download from [github.com/mangoh](http://github.com/mangoh). Let me know if you run into issues. regards, Ashish ---
**Author:** ![toanmh](https://avatars.discourse-cdn.com/v4/letter/t/48db29/32.png) [@toanmh](https://mangoh.discourse.group/u/toanmh)\ **Post date:** [July 7, 2016, 7:50pm UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/3 "2016-07-07T19:50:32Z")
Thank for your help Yes, I want to using to derect PCM but now I don’t have seirra wp, I’m using the HL8548. Can I config or change the hardware board to do that? I tried connect the CN601 but the logic voltage is too low (about 200mv). ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [July 7, 2016, 9:04pm UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/4 "2016-07-07T21:04:08Z")
you should be able to use CN602, it is a direct connection.Are you sending any AT command to activate your HL module for PCM? Usually PCM lines will be low unless you activate them. ---
**Author:** ![toanmh](https://avatars.discourse-cdn.com/v4/letter/t/48db29/32.png) [@toanmh](https://mangoh.discourse.group/u/toanmh)\ **Post date:** [July 8, 2016, 2:48am UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/5 "2016-07-08T02:48:07Z")
Thank Asyal for quick supported ![](https://us1.discourse-cdn.com/flex016/uploads/mangoh/original/1X/1f944d0ede22dbc53c6239ea8d65903efdef142b.png) I thing the PCM directing connection is CN601. I tested the PCM by answer an calling. The clock, data, ck sync is seam ok . But I was measured the logic voltage by oscilloscope is very low (~200mv). What the other way disable the codec ic ? I read document: Can I config the Mux1 via hardware? ![](https://us1.discourse-cdn.com/flex016/uploads/mangoh/original/1X/9de9e18f77391f3c681bbebc2c4a3ffbeabe40c2.png) ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [July 8, 2016, 3:04am UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/6 "2016-07-08T03:04:00Z")
You need to disable U910. So resistor R910 should be removed and try to pull PCM\_EXP1\_ENn to high (1.8V should be enough) ---
**Author:** ![asyal](https://sea2.discourse-cdn.com/flex016/user_avatar/mangoh.discourse.group/asyal/32/78_2.png) [@asyal](https://mangoh.discourse.group/u/asyal)\ **Post date:** [March 6, 2017, 5:24am UTC](https://mangoh.discourse.group/t/how-to-configuration-to-using-pcm-in-iot-0/143/7 "2017-03-06T05:24:59Z")