Embarking on a new audio project and diving into the world of Bluetooth chips? Many enthusiasts, especially those exploring DIY audio and custom sound solutions, find themselves drawn to the versatile CSR8675. If you’re new to this forum and considering using the CSR8675, let’s explore its capabilities and some common experiences in getting started.
Like many, my initial foray into the CSR8675 began with acquiring a module – in my case, the CSR8675 Bluetooth Card Decoder Module Amplifier. This readily available board is a popular starting point for those wanting to experiment with the chip’s potential.
Alt: CSR8675 Bluetooth module for DIY audio projects, popular among hobbyists.
To begin programming, accessing the right development tools is crucial. The ADK (Application Development Kit) from Qualcomm (formerly CSR) is essential. Fortunately, online communities and forums often provide access to older ADK versions like 4.4, 4.3, and 4.1. Setting up a virtual Windows 7 64bit environment is a recommended step to ensure compatibility with these older toolchains.
Connecting to the chip using the PS tool (part of the ADK) reveals the factory firmware. In my case, it reported version 13083, identified as “rck_16unified_fl_bt5.0_u28c_1705050747_ble_encr128 2017-05-05”. Understanding your starting firmware is a key first step before making modifications.
Alt: PS Tool displaying firmware version of CSR8675 chip, essential for debugging.
The goal for many projects, including mine, extends beyond basic Bluetooth audio reception. Integrating I2S for high-quality DAC output and establishing serial communication (UART) with a microcontroller opens up exciting possibilities. Imagine displaying media player information like song titles and playback time on a display connected via UART – a fantastic enhancement for any audio system. Resources like the 52bluetooth.com site offer valuable insights into UART communication with CSR chips.
Starting with ADK 4.4, configuring the project in XIDE for CSR8675 and setting AHI-Transport to SPI seems straightforward. Flashing the new firmware from ADK 4.4, merging the ‘sink_system_csr8675.psr’ file, and compiling and debugging allows Bluetooth pairing. However, initial configurations often default to DAC output. Switching to I2S/PCM via the ADK sink configuration tool is necessary to match hardware setups using I2S DACs.
Post-firmware update, the PS tool might report a newer version like “rck_16unified_fl_bt5.0_u30a_1809201429_ble_encr128 2018-09-20”. This indicates successful firmware flashing.
Alt: ADK Configuration Tool interface for setting up audio output on CSR8675.
However, challenges can arise. Write errors in the ADK configuration tool, specifically issues writing to block 33, have been reported, sometimes linked to ADK 4.4 bugs. Downgrading to ADK 4.3 might seem like a solution, but it can introduce new problems. While write errors might disappear, attempting to switch audio output to I2S could lead to chip malfunctions or VM panic errors. Furthermore, device visibility for pairing might become inconsistent. ADK 4.1, while older, lacks AHI-Transport settings and has a different feature set in the configuration tool, making it potentially less suitable for modern I2S setups.
A common roadblock is ADK configuration tool compatibility with the original firmware. “Ahi.dll consistency error” can prevent using configuration tools from different ADK versions on the factory firmware, creating a standstill.
The journey of programming the CSR8675, while sometimes frustrating, is ultimately rewarding. Exploring different ADK versions and troubleshooting issues are part of the learning curve. If you are facing similar challenges or have experience with ADK 4.2, sharing insights and resources within the community is invaluable. And while the term “8675 Song” might not be technically accurate, the CSR8675 chip certainly plays a crucial role in enabling countless songs and audio experiences in the world of Bluetooth audio.
