# USB **URL:** https://forum.amebaiot.com/c/freertos/usb/76.md [Latest](https://forum.amebaiot.com/latest.md) · [Categories](https://forum.amebaiot.com/categories.md) · [Tags](https://forum.amebaiot.com/tags.md) --- ## [About the FreeRTOS USB category](https://forum.amebaiot.com/t/about-the-freertos-usb-category/4427)
**Author:** [@emch](https://forum.amebaiot.com/u/emch)\ **Replies:** 0\ **Last updated:** [October 24, 2025, 6:13am UTC](https://forum.amebaiot.com/t/about-the-freertos-usb-category/4427 "2025-10-24T06:13:51Z")
For all topics related to FreeRTOS USB solution: device, host, drd, otg, etc. 讨论关于 FreeRTOS USB 解决方案的所有话题，包含外设、主机、DRD、OTG 等各种应用。 --- ## [AMB82-Mini USB Host CDC ECM fails to enumerate Quectel EC200U 4G modem — "ecm init fail"](https://forum.amebaiot.com/t/amb82-mini-usb-host-cdc-ecm-fails-to-enumerate-quectel-ec200u-4g-modem-ecm-init-fail/4802)
**Author:** [@Pradeep\_1](https://forum.amebaiot.com/u/Pradeep_1)\ **Replies:** 8\ **Last updated:** [September 9, 2026, 5:17am UTC](https://forum.amebaiot.com/t/amb82-mini-usb-host-cdc-ecm-fails-to-enumerate-quectel-ec200u-4g-modem-ecm-init-fail/4802 "2026-09-09T05:17:58Z")
Hi Realtek team, I am developing a 4G dashcam using AMB82-Mini ( RTL8735B) with a Quectel EC200U-CN 4G modem ( Quectel EC200U 4G Modem - CAPUF ). The modem is configured for USB CDC ECM mode via AT+QCFG=“usbnet”,1. UART… --- ## [AMB82-mini USB host CDC ECM fail to SIM7600G-H](https://forum.amebaiot.com/t/amb82-mini-usb-host-cdc-ecm-fail-to-sim7600g-h/4821)
**Author:** [@termy](https://forum.amebaiot.com/u/termy)\ **Replies:** 4\ **Last updated:** [September 4, 2026, 9:27pm UTC](https://forum.amebaiot.com/t/amb82-mini-usb-host-cdc-ecm-fail-to-sim7600g-h/4821 "2026-09-04T21:27:33Z")
Hi, Pammy, I use rtl8735b usb host to connect SIM7600G-H via CDC ECM. My SIM700G-H test on Linux vid CDC ECM is ok, so I use same method to rtl8735b and I got following message: #UECM \[ECM\] USB host ECM demo started… --- ## [AMB82 Mini - USB-UVC 攝影機 for macOS](https://forum.amebaiot.com/t/amb82-mini-usb-uvc-for-macos/4956)
**Author:** [@t112c53029](https://forum.amebaiot.com/u/t112c53029)\ **Replies:** 6\ **Last updated:** [July 22, 2026, 7:04am UTC](https://forum.amebaiot.com/t/amb82-mini-usb-uvc-for-macos/4956 "2026-07-22T07:04:42Z")
請問Ameba82 mini 的 free rtos sdk uvc example之後會打算支援macos?我在mac只有讀到相機，但vlc或內建facetime都沒有畫面。我在上面只找到目前只支援windows potplayer 或microsoft teams 、googlemeet 等平台 --- ## [AMB82-mini: USB Ethernet failing](https://forum.amebaiot.com/t/amb82-mini-usb-ethernet-failing/4803)
**Author:** [@k-adarsh](https://forum.amebaiot.com/u/k-adarsh)\ **Replies:** 18\ **Last updated:** [May 29, 2026, 2:36am UTC](https://forum.amebaiot.com/t/amb82-mini-usb-ethernet-failing/4803 "2026-05-29T02:36:47Z")
Hey everyone, I’m trying to get the USB Ethernet (CDC-ECM) example (link to USB example) working on my AMB82-mini with a RTL8152B USB Ethernet dongle, but I’m hitting a wall. The board seems to initialize and sometimes … --- ## [Use the AMB 82 mini as a USB Keyboard Input Device](https://forum.amebaiot.com/t/use-the-amb-82-mini-as-a-usb-keyboard-input-device/4652)
**Author:** [@Harry\_Poun](https://forum.amebaiot.com/u/Harry_Poun)\ **Replies:** 1\ **Last updated:** [January 20, 2026, 1:20am UTC](https://forum.amebaiot.com/t/use-the-amb-82-mini-as-a-usb-keyboard-input-device/4652 "2026-01-20T01:20:08Z")
Hello, I would like to configure the AMB 82 mini to function as a USB keyboard input device. However, upon reviewing the SDK, I noticed that the USB Device section seems to only offer interfaces related to a mouse. Could… --- ## [Using RT8735B for wireless transmission of external UVC to Raspberry Pi](https://forum.amebaiot.com/t/using-rt8735b-for-wireless-transmission-of-external-uvc-to-raspberry-pi/4573)
**Author:** [@Abi\_Rusalavitch](https://forum.amebaiot.com/u/Abi_Rusalavitch)\ **Replies:** 4\ **Last updated:** [December 11, 2025, 3:01am UTC](https://forum.amebaiot.com/t/using-rt8735b-for-wireless-transmission-of-external-uvc-to-raspberry-pi/4573 "2025-12-11T03:01:43Z")
Hi, I have found some older posts regarding UVC support on the RT8735B, but some of them said that the firmware or examples were under NDA. I am working on my senior capstone for my undergrad, and I was wondering if thi… --- ## [Tinyusb](https://forum.amebaiot.com/t/tinyusb/4489)
**Author:** [@Aureliano\_Pisa](https://forum.amebaiot.com/u/Aureliano_Pisa)\ **Replies:** 3\ **Last updated:** [November 20, 2025, 7:49am UTC](https://forum.amebaiot.com/t/tinyusb/4489 "2025-11-20T07:49:48Z")
Is there a consideration to add RTL8735B to the tinyusb project? It would be helpful for managing a composite device, having wider community, and for me, to have proper high speed UAC2 --- ## [Can the AMB82-Mini USB port be used with memory sticks?](https://forum.amebaiot.com/t/can-the-amb82-mini-usb-port-be-used-with-memory-sticks/4312)
**Author:** [@Barryn56](https://forum.amebaiot.com/u/Barryn56)\ **Replies:** 3\ **Last updated:** [August 25, 2025, 7:49am UTC](https://forum.amebaiot.com/t/can-the-amb82-mini-usb-port-be-used-with-memory-sticks/4312 "2025-08-25T07:49:40Z")
I am considering using memory sticks as a more convenient storage medium, rather than SD cards. Can the USB OTG port on the AMB82-mini be used for this purpose? --- ## [AMB82 mini as a uvc](https://forum.amebaiot.com/t/amb82-mini-as-a-uvc/3789)
**Author:** [@Harsh\_Raj](https://forum.amebaiot.com/u/Harsh_Raj)\ **Replies:** 3\ **Last updated:** [July 18, 2025, 1:44am UTC](https://forum.amebaiot.com/t/amb82-mini-as-a-uvc/3789 "2025-07-18T01:44:56Z")
While using amb82 mini as a uvc device, I am getting output as “fun\_suspend” in the serial monitor. The device is recognised by my laptop as a camera but it is not working. --- ## [RTL8721DM USBD\_Vendor 连接华为平板M6 Android10 枚举失败](https://forum.amebaiot.com/t/rtl8721dm-usbd-vendor-m6-android10/4116)
**Author:** [@zhuzeyu](https://forum.amebaiot.com/u/zhuzeyu)\ **Replies:** 2\ **Last updated:** [May 28, 2025, 1:55am UTC](https://forum.amebaiot.com/t/rtl8721dm-usbd-vendor-m6-android10/4116 "2025-05-28T01:55:24Z")
你好，2023 年 4月 -（ 我们使用RTL8721DM 的USBD\_MSC功能时，发现连接华为MATEPAD或有些平板时，会出现死机，无法通信，只能重启。SDK:1.0.1 把sdk-amebad\_v6.2里的USBD\_MSC的代码移植到新的SDK1.0.1中，可以用，但会出现上面描述的现象。）这个帖子发了补丁包后确实改善了。但目前又有新问题，就是我们产品使用 RTL8721DM 的USBD\_Vendor 设备方式连接华为Andro… --- ## [Where can I find the docs of USB API?](https://forum.amebaiot.com/t/where-can-i-find-the-docs-of-usb-api/2663)
**Author:** [@zjulic](https://forum.amebaiot.com/u/zjulic)\ **Replies:** 1\ **Last updated:** [February 5, 2024, 3:07am UTC](https://forum.amebaiot.com/t/where-can-i-find-the-docs-of-usb-api/2663 "2024-02-05T03:07:27Z")
I can’t find any documentation on USB API or USB stack. Where can I find them if I want to know the detailed information of the API functions like usbd\_init/usbd\_ep\_transmit? --- ## [BLE beacon build](https://forum.amebaiot.com/t/ble-beacon-build/782)
**Author:** [@brcisna](https://forum.amebaiot.com/u/brcisna)\ **Replies:** 8\ **Last updated:** [February 5, 2024, 3:04am UTC](https://forum.amebaiot.com/t/ble-beacon-build/782 "2024-02-05T03:04:44Z")
Hello All, Trying to find out if there are build options someplace in the Standard SDK to compile a BLE beacon bit the RTL8720dn rtlduino , BW16 module ? There none that I see in the ‘examples’ directory. Am very illet… --- ## [RTL8721DM USBD\_MSC 连接华为或有些平板是死机](https://forum.amebaiot.com/t/rtl8721dm-usbd-msc/1824)
**Author:** [@zhuzeyu](https://forum.amebaiot.com/u/zhuzeyu)\ **Replies:** 1\ **Last updated:** [April 24, 2023, 1:43am UTC](https://forum.amebaiot.com/t/rtl8721dm-usbd-msc/1824 "2023-04-24T01:43:41Z")
你好，我们使用RTL8721DM 的USBD\_MSC功能时，发现连接华为MATEPAD或有些平板时，会出现死机，无法通信，只能重启。SDK:1.0.1 把sdk-amebad\_v6.2里的USBD\_MSC的代码移植到新的SDK1.0.1中，可以用，但会出现上面描述的现象。 --- ## [RTL8721可以支援當USB Host，並支援USB device (UART)嗎?](https://forum.amebaiot.com/t/rtl8721-usb-host-usb-device-uart/1632)
**Author:** [@iron](https://forum.amebaiot.com/u/iron)\ **Replies:** 3\ **Last updated:** [February 8, 2023, 5:29am UTC](https://forum.amebaiot.com/t/rtl8721-usb-host-usb-device-uart/1632 "2023-02-08T05:29:30Z")
請問RTL8721可以支援當USB Host，並支援USB device (UART)嗎? (我知道RTL87210有UART介面，但要接的裝置是USB介面。所以必需要能做USB Host角色來接此USB device(UART) ) --- ## [Ameba RTL8722DM How to turn on USB host](https://forum.amebaiot.com/t/ameba-rtl8722dm-how-to-turn-on-usb-host/1304)
**Author:** [@jimhuang0708](https://forum.amebaiot.com/u/jimhuang0708)\ **Replies:** 4\ **Last updated:** [December 30, 2022, 7:03am UTC](https://forum.amebaiot.com/t/ameba-rtl8722dm-how-to-turn-on-usb-host/1304 "2022-12-30T07:03:26Z")
翻閱整個SDK似乎所有有關於usb 的 source/header 都是空的? --- ## [Amebaz2 - BLE CCCD Default](https://forum.amebaiot.com/t/amebaz2-ble-cccd-default/1365)
**Author:** [@wanglemao](https://forum.amebaiot.com/u/wanglemao)\ **Replies:** 5\ **Last updated:** [August 29, 2022, 9:43am UTC](https://forum.amebaiot.com/t/amebaz2-ble-cccd-default/1365 "2022-08-29T09:43:19Z")
我声明了一个notify的cccd，初始值为：DNA\_BLE\_GATT\_CLIENT\_CHAR\_CONFIG\_NOTIFY，代码如下 /\* 6 读取服务CCCD初始化 \*/ { DNA\_BLE\_ATTRIB\_FLAG\_VALUE\_INCL | DNA\_BLE\_ATTRIB\_FLAG\_CCCD\_APPL, { DNA\_BLE\_LO\_WORD(DNA\_BLE\_GATT\_UUID\_CHAR\_CLIENT\_CO… --- ## [RTL8722DM : BT example](https://forum.amebaiot.com/t/rtl8722dm-bt-example/462)
**Author:** [@cavo](https://forum.amebaiot.com/u/cavo)\ **Replies:** 4\ **Last updated:** [April 13, 2021, 7:20am UTC](https://forum.amebaiot.com/t/rtl8722dm-bt-example/462 "2021-04-13T07:20:01Z")
I set it up like AN0400 Ameba-D Application Note(page. 258) However, error is occurred as shown in the following. make\[2\]: Entering directory ‘/cygdrive/d/2.Project/1.xPod/Software/ambd\_sdk-master/project/realtek\_ame…