# RTL8720DN - MQ3

**URL:** https://forum.amebaiot.com/t/rtl8720dn-mq3/1406
**Category:** Peripherals
**Tags:** rtl872xd, evb-bw16
**Created:** [August 17, 2022, 3:34pm UTC](https://forum.amebaiot.com/t/rtl8720dn-mq3/1406 "2022-08-17T15:34:08Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![rkuo2000](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/rkuo2000/32/1105_2.png) [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [August 17, 2022, 3:34pm UTC](https://forum.amebaiot.com/t/rtl8720dn-mq3/1406/1 "2022-08-17T15:34:08Z")

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[RTL8720DN\_MQ3.ino](https://github.com/rkuo2000/arduino/blob/master/examples/RTL8720DN/RTL8720DN_MQ3/RTL8720DN_MQ3.ino)

The code runs good in ESP32, when I run it on RTL8720DN  
I can not use the following two functions:

// analogSetPinAttenuation(ADC\_pin, ADC\_11db);  
// adcAttachPin(ADC\_pin);

Anyway to set bit width of ADC?  
Is RTL8720DN’s ADC value in 10-bit ? 12-bit ?

Your answwer will be appreciated !

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### Author: ![xidameng](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/xidameng/32/18_2.png) [@xidameng](https://forum.amebaiot.com/u/xidameng)
#### Post date: [August 18, 2022, 5:52am UTC](https://forum.amebaiot.com/t/rtl8720dn-mq3/1406/2 "2022-08-18T05:52:03Z")

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Hi @rkuo2000

May I know which RTL8720DN dev board are you using?

> [@rkuo2000](#):
>
> I can not use the following two functions:
> 
> // analogSetPinAttenuation(ADC\_pin, ADC\_11db);  
> // adcAttachPin(ADC\_pin);

These 2 functions are not implemented at the moment, if they are requested by multiple users on Github, we might add it in the future release~

> [@rkuo2000](#):
>
> Is RTL8720DN’s ADC value in 10-bit ? 12-bit ?

Ameba D all have 12-bit SAR ADC

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### Author: ![rkuo2000](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/rkuo2000/32/1105_2.png) [@rkuo2000](https://forum.amebaiot.com/u/rkuo2000)
#### Post date: [August 18, 2022, 6:28am UTC](https://forum.amebaiot.com/t/rtl8720dn-mq3/1406/3 "2022-08-18T06:28:19Z")

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《iCshop1》Ameba BW16 type C RTL8720DN 開發板●368030501730●  
[https://www.ruten.com.tw/item/show?22230908622950](https://www.ruten.com.tw/item/show?22230908622950)

SimonXI via Realtek Ameba IOT Developers Forum (RTL8722 RTL8195 RTL8710 RTL8720 BW16 Development board) - IOT / MCU Solutions 瑞昱開發者論壇 開發板 开發者论坛 开發板 \<[notifications@ameba.discoursemail.com](mailto:notifications@ameba.discoursemail.com)\> 於 2022年8月18日 週四 14:02 寫道：