# RTL8722DM scan WiFi issue for 5Ghz **URL:** \ **Category:** Hardware\ **Tags:** rtl872xd\ **Created:** [June 7, 2022, 6:54am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288 "2022-06-07T06:54:31Z")\ **Posts on this page:** 19\ **Page:** 1
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 7, 2022, 6:54am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/1 "2022-06-07T06:54:31Z")
Hi, we are developing Wifi module board with rtl8722dm and have 5Ghz scan issue. The AMB23 SDK shows 2.4GHz and 5GHz scan results for "ScanNetworks " and “BLEWifiConfig” in sketch examples, but our board shows only 2.4GHz. Our board design or wiring is suspect to this matter. We like to know how the arduino code checks the hardware wiring and cognize 5Ghz part not working. If someone knows code description, pls let me know and your support will be appreciated. Thank you. ---
**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:** [June 7, 2022, 8:17am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/2 "2022-06-07T08:17:49Z")
What RTL8722DM board do you use? could you post a link or paste a photo of it? ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 7, 2022, 11:45pm UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/3 "2022-06-07T23:45:07Z")
Sorry, it is a still developing board and cannot disclose the details and photo. The design is similar to SDK board AMD23 , which show 2.4 & 5GHz scan results. I wonder some configuration needed before use. Thank you. ---
**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:** [June 8, 2022, 2:01am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/4 "2022-06-08T02:01:27Z")
> [@kkuma](#): > > I wonder some configuration needed before use. There is no configuration needed to use 5G wifi band, it’s enabled by default, provided your PCB design and antenna design are capable of 5GHz signal band ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 8, 2022, 5:33am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/5 "2022-06-08T05:33:39Z")
Thanks for your advice and understand 5Ghz can be used in default. Is there any command somewhere in sketch to use 2.4 or 5Ghz, respectively if possible ? ---
**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:** [June 8, 2022, 7:19am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/6 "2022-06-08T07:19:31Z")
> [@kkuma](#): > > Is there any command somewhere in sketch to use 2.4 or 5Ghz, respectively if possible ? nope, Ameba treat 2.4G and 5G all the same ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 8, 2022, 8:24am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/7 "2022-06-08T08:24:07Z")
Ok, thank you. how about any special board/chip pin wiring related to 5ghz ? ---
**Author:** ![wyy](https://avatars.discourse-cdn.com/v4/letter/w/bc8723/32.png) [@wyy](https://forum.amebaiot.com/u/wyy)\ **Post date:** [June 8, 2022, 10:13am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/8 "2022-06-08T10:13:08Z")
@kkuma I believe a RF diplexer is used to combine and separate the two RF bands onto one antenna. ![image](https://us1.discourse-cdn.com/flex016/uploads/ameba/original/2X/6/6e9e712cfe01f9387623c0c4a7a7130df6464b3f.png) Taken from the reference [module schematics](https://www.amebaiot.com/en/hdk-download-8722dm/) ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 9, 2022, 1:21am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/9 "2022-06-09T01:21:32Z")
Thank you for update. Let me talk to designer. ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 10, 2022, 12:07am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/10 "2022-06-10T00:07:38Z")
Hi, our designer wonders is there any reason that diplexer must be used. how about the circuit which conflating 2.4 and 5 GHz bands ? Is this causing any problem ? ---
**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:** [June 10, 2022, 1:54am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/11 "2022-06-10T01:54:30Z")
Hi @kkuma Antenna design is a very specific and higly sophisticated work, thus we advise you to consult the professionals in this field to get the most accurate response. If you have contact to a Realtek FAE, feel free to contact them regarding the IC usage. PS: This forum is more for the **open source** software/hardware discussion ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 10, 2022, 3:31am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/12 "2022-06-10T03:31:21Z")
Hi, xidameng Thanks for your reply and yes, this is very specific matter as you mentioned. Any way to send command for ic or board to check transmission power, or etc. ? ---
**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:** [June 13, 2022, 1:20am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/13 "2022-06-13T01:20:33Z")
@kkuma You may refer to the link below to access docmumentations related to Realtek AT Commands > **[ambd\_sdk/doc at 12dab4363fd0087eb4874461f8d3f6094110595f · ambiot/ambd\_sdk](https://github.com/ambiot/ambd_sdk/tree/12dab4363fd0087eb4874461f8d3f6094110595f/doc)** > > 12dab4363fd0087eb4874461f8d3f6094110595f/doc ---
**Author:** ![kkuma](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kkuma/32/1649_2.png) [@kkuma](https://forum.amebaiot.com/u/kkuma)\ **Post date:** [June 13, 2022, 11:44pm UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/14 "2022-06-13T23:44:44Z")
Hi, Thank you, xidameng, I going to look through these files. ---
**Author:** ![Andrey\_Galinovskiy](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/andrey_galinovskiy/32/1328_2.png) [@Andrey\_Galinovskiy](https://forum.amebaiot.com/u/Andrey_Galinovskiy)\ **Post date:** [July 7, 2023, 3:25pm UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/15 "2023-07-07T15:25:22Z")
Hi. Did you manage to solve this issue with 5Ghz networks scan? ---
**Author:** ![dakamaster](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/dakamaster/32/1744_2.png) [@dakamaster](https://forum.amebaiot.com/u/dakamaster)\ **Post date:** [July 10, 2023, 1:41am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/16 "2023-07-10T01:41:16Z")
Hi @Andrey_Galinovskiy, Greetings! Welcome to AmebaIoT Family. 😃 Currently, there is no issue with scanning 5GHz WiFi on the AmebaD board. Thanks for asking. ---
**Author:** ![Andrey\_Galinovskiy](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/andrey_galinovskiy/32/1328_2.png) [@Andrey\_Galinovskiy](https://forum.amebaiot.com/u/Andrey_Galinovskiy)\ **Post date:** [July 10, 2023, 1:29pm UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/17 "2023-07-10T13:29:00Z")
Thank you for your answer but i have RTL-AMEBAD\_MB\_3V0 RTL8722CSM and scan return only 2,4 Ghz networks. Cannot understand why ---
**Author:** ![oxygenben](https://avatars.discourse-cdn.com/v4/letter/o/4bbf92/32.png) [@oxygenben](https://forum.amebaiot.com/u/oxygenben)\ **Post date:** [July 24, 2023, 1:10am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/19 "2023-07-24T01:10:16Z")
![image](https://us1.discourse-cdn.com/flex016/uploads/ameba/original/2X/c/cd73b9293b386bc640747ccd4d31919fdda3aaa5.png) RTL8722CSM support only 2.4G ---
**Author:** ![dakamaster](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/dakamaster/32/1744_2.png) [@dakamaster](https://forum.amebaiot.com/u/dakamaster)\ **Post date:** [July 24, 2023, 2:32am UTC](https://forum.amebaiot.com/t/rtl8722dm-scan-wifi-issue-for-5ghz/1288/20 "2023-07-24T02:32:25Z")
Hi @Andrey_Galinovskiy , You may refer to the image below for further understanding of the module naming conventions. ![image](https://us1.discourse-cdn.com/flex016/uploads/ameba/original/2X/4/43ae56f11b642ce81c3193c61051fc43503bf20e.jpeg)