# How to change a list of available channels for bw16 **URL:** \ **Category:** Multimedia\ **Tags:** evb-bw16, rtl872xd\ **Created:** [March 5, 2025, 8:22pm UTC](https://forum.amebaiot.com/t/how-to-change-a-list-of-available-channels-for-bw16/3894 "2025-03-05T20:22:23Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Alexandr](https://avatars.discourse-cdn.com/v4/letter/a/71c47a/32.png) [@Alexandr](https://forum.amebaiot.com/u/Alexandr)\ **Post date:** [March 5, 2025, 8:22pm UTC](https://forum.amebaiot.com/t/how-to-change-a-list-of-available-channels-for-bw16/3894/1 "2025-03-05T20:22:24Z")
Hello everyone. i have Arduino IDE and install bordManager realtek for use rtl8720dn. I have a questions: i need to change available channel list for scanning and work BW 16. I find information in file …AmebaD\3.1.7\system\component\common\api\wifi\wifi\_conf.c about channellist #define SCAN\_CHANNEL\_NUM 13+25 [//2.4GHz](https://2.4GHz) + 5GHz u8 scan\_channel\_list[SCAN\_CHANNEL\_NUM] = {1,2,3,4,5,6,7,8,9,10,11,12,13, 36,40,44,48,52,56,60,64,100,104,108,112,116,120,124,128,132,136,140,144,149,153,157,161,165}; i add 14 channel amd increase SCAN\_CHANNEL\_NUM to 14+25 and press compile in Arduino IDE and nothink ^((( also rename file to .cpp and rename function wifi\_scan\_networks\_mcc to wifi\_scan\_networks\_mcc2 also in heder i put the error message undefined function wifi\_scan\_networks\_mcc2 because file cpp or c not working in procecc compile, instead working /AmebaD/3.1.7/variants/common\_libs/lib\_arduino.a how to recompile function to increase count of scanned channels? also later i create own heder and cpp file contains needed variable and functions - its all from wifi\_conf.c & \ success compile and nothing 14 or 169 channells is not working ^( i look sdr and another - not work. also wifi\_set\_channel\_plan & wifi\_get\_channel\_plan returned nothink ^( uint8\_t \*channel\_plan = 0; int res = RTW\_SUCCESS; res = wifi\_set\_channel\_plan(RTW\_COUNTRY\_JP); /\*res = wifi\_get\_channel\_plan(channel\_plan); Serial.print("channel\_plan = "); Serial.println(\*channel\_plan); \*/ if( res == RTW\_SUCCESS) Serial.println(“RTW\_SUCCESS”); else if( res == RTW\_ERROR) Serial.println(“RTW\_ERROR”); how to use 14, 169, 171 and 177 channels for bw16? ---
**Author:** ![KevinKL](https://sea2.discourse-cdn.com/flex016/user_avatar/forum.amebaiot.com/kevinkl/32/2632_2.png) [@KevinKL](https://forum.amebaiot.com/u/KevinKL)\ **Post date:** [March 7, 2025, 1:58am UTC](https://forum.amebaiot.com/t/how-to-change-a-list-of-available-channels-for-bw16/3894/2 "2025-03-07T01:58:22Z")
Hi @Alexandr , `#define SCAN_CHANNEL_NUM 13+25 // 2.4GHz + 5GHz` refers to the number of channels to scan If you would like to use other channel which is not found in `u8 scan_channel_list`, you modify the scan channel list (i.e. replacing those channel numbers which are not used in your channel plan with 14, 169, 171 and 177). Hope it helps. Thank you. ---
**Author:** ![Alexandr](https://avatars.discourse-cdn.com/v4/letter/a/71c47a/32.png) [@Alexandr](https://forum.amebaiot.com/u/Alexandr)\ **Post date:** [March 7, 2025, 2:20pm UTC](https://forum.amebaiot.com/t/how-to-change-a-list-of-available-channels-for-bw16/3894/3 "2025-03-07T14:20:21Z")
HI no, uncle - its not woking. file with name wifi\_conf.c or wifi\_conf.cpp not used during compilation donot think i so stupid ^))) arduino ide using binary file coommon/arduino.a during compile the project. i can delete wifi\_conf.c and nothing changed ^))) questions how to recompile coommon/arduino.a ?