Summary of HLK-7688A OPENWRT DEVELOPMENT BOARD COMES WITH AN AUDIO JACK
This article introduces an OpenWrt audio board featuring the Hi-Link HLK-7688A module, designed for streaming audio and video to multiple phones. While the hardware includes a MediaTek MT7688 processor, USB ports, and an audio jack, users report significant software limitations. Specifically, the latest OpenWrt versions lack I2S and I2C support, making it difficult to achieve sound output despite the presence of a WM8960 codec.
Parts used in the HLK-7688A Audio Board:
- HLK-7688A Module
- MediaTek MT7688 MIPS24KEc Processor
- 32MB RAM
- 128MB Flash Storage
- MicroSD Card Slot
- 802.11 b/g/n WiFi 4 Module
- u.FL Antenna Connector
- 10/100M Ethernet Port
- 3.5mm Audio Jack
- 4-Pin Speaker Header
- WM8960 Audio Codec
- 2x Micro USB Ports
- 2x 26-Pin Headers with GPIOs
- Status LEDs (WiFi, LAN, USB)
- Reset Button
- Factory Reset Button
Another OpenWrt audio board based on the processor with HLK-7688A board featuring Hi-Link HLK-7688A module is launched.
HLK-7688A board specifications:
- Wireless Module – HLK-7688A based on MediaTek MT7688 MIPS24KEc processor @ 580 MHz, and equipped with 32MB RAM, 128MB flash
- Storage – MicroSD card slot
- Connectivity
- 802.11 b/g/n WiFi 4 up to 150 Mbps with u.FL antenna connector
- 10/100M Ethernet
- Audio – 3.5mm audio jack; 4-pin speaker header, WM8960 audio codec
- USB – 2x Micro USB ports one USB 2.0 port and one for debugging & power
- Expansion – 2x 26-pin headers with GPIO’s, SPI, UART, I2C, I2S, Ethernet, USB, GND, 3.3V…
- Misc – 4x status LED’s for WiFi, LAN, USB, and WiFi; reset button, factory reset button (long press)
- Power Supply – 5V via Micro USB port
- Dimensions – Module: 32.8 x 18 mm; Board (est): 75 x 34 mm
The board is apparently sold as a video and/or audio streamer storing files in USB storage or MicroSD card to be played on your phone. Up to 8 phones are supported for photo sharing, and 3 phones for simultaneous video streaming.
One of the photos of the board shows it supports OpenWrt 3.10 with Linux 2.6.36 SDK. It’s probably a mistake, as when I tested the MediaTek LinkIt board two years ago, it ran Linux 3.18.21, OpenWrt Chaos Calmet 15.05+.
One buyer also mentions USB audio works just fine with Linkit firmware, and the latest version of OpenWrt can run on the board but without I2S nor I2C support. He later updated his comment with further details:
Openwrt driver support is left at v15 and even this version 15 is full of bugs. I2S is “mission impossible” andI could not get sound out of that board
If despite the software shortcomings, you’re still interested in the board, it can be purchased for $16.70 with WiFi antenna on Aliexpress, or alternatively you could get the module only for $10 shipped from the same link.
Read more: HLK-7688A OPENWRT DEVELOPMENT BOARD COMES WITH AN AUDIO JACK
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What is the primary function of this board?
The board is sold as a video and/or audio streamer that stores files on USB or MicroSD cards for playback on phones. -
How many phones can connect simultaneously?
Up to 8 phones are supported for photo sharing, while 3 phones can handle simultaneous video streaming. -
Does the latest version of OpenWrt support I2S?
No, the latest version of OpenWrt runs on the board but does not support I2S or I2C. -
Can users get sound out of the board with current drivers?
Users report that getting sound out is a mission impossible because driver support remains at v15 which is full of bugs. -
What Linux kernel version was expected versus what was tested?
A photo suggested Linux 2.6.36 SDK, but testing on similar LinkIt boards previously showed Linux 3.18.21. -
Is USB audio functional on this device?
One buyer mentions that USB audio works just fine when using Linkit firmware. -
Where can this board be purchased?
The board can be purchased for $16.70 with a WiFi antenna on Aliexpress. -
What is the cost if buying only the module?
You can get the module only for $10 shipped from the same Aliexpress link.
