Pico-ASHA is an attempt to implement Android's Audio Streaming for Hearing Aids (ASHA) protocol on a Raspberry Pi Pico W microcontroller.
This project is still highly experimental. Currently, it is possible to discover (Oticon) hearing aids, and limited audio streaming has been implemented.
It should be safe, but I cannot guarantee it will not mess up your hearing aids!
Download pico-sdk 1.5.1, using the provided instructions.
Create an environment variable called PICO_SDK_PATH that points to the downloaded SDK location.
Obtain an updated BT firmware to fix an issue with Data Length Extensions (DLE). Download and apply the patch from this github comment. Hopefully the next version of the Pico SDK will include this fix.
Build pico-asha
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=MinSizeRel ..
cmake --build .To load the program onto your Pico W, press the BOOTSEL button while plugging it into the PC over USB. Then copy the asha.uf2 onto the mass storage device.
By default, Pico-ASHA logs output via UART. To view debugging info over UART, you will need a method to interface with the UART pins. Such options include another pico using the debugprobe project, a USB to UART adapter, The Raspberry Pi debug probe, a full Raspberry Pi or other SBC etc.
Alternatively, Pico-ASHA can log output via USB serial using the standard Raspberry Pi Pico serial settings:
- Baud Rate: 115200
- Data Bits: 8
- Stop Bits:" 1
- Parity: None
- DTR and RTS enabled
Pass -DENABLE_USB_SERIAL=ON to cmake during configure to enable USB serial.
It is possbile to load new versions of the software without having to press the BOOTSEL button. If you have a SWD connection setup (by using a debug probe), you can use OpenOCD to upload new firmware.
The source code in this repository is licenced under the BSD 3-clause licence, however any binaries must be provided on a more restrictive licence, see below.
Pico-ASHA uses BTstack by BlueKitchen, which in general has a non-commercial free licence available. Raspberry Pi have provided a commercial licence if using BTstack on official Raspberry Pi Pico W or WH. If Pico-ASHA is implemented on any other device, then the terms of the original BlueKitchen BTstack licence MUST be adhered to.