Tuesday 9 June 2015

Bluetooth fixes and software improvements

Hello and welcome to post #13 of my blog on building a complete in-car computer system. In this post I will cover various software and hardware changes I have made to improve the performance of the Bluetooth system and various software components.

To start off with, I use the system to wirelessly stream music from my smartphone to the computer via Bluetooth. However from the start this functionality has been glitchy. The audio stream is not smooth an continuous as it should be, rather it stutters and occasionally stops working for lengthy periods.

The cause of this is not fully known as I lack the proper instrumentation to find the source of the problem. However based on the symptoms of the problem it is clear that there is some sort of interference affecting the 2.4ghz wireless Bluetooth signal which results in disrupted commiseration between the smartphone and computer. This could be due to the poor placement of the PCIe wireless communications card on the motherboard (though ASUS had little choice due to the very compact form factor of the board), which is very close to the rear panel and is known is known to be affected by nearby USB3 ports and controllers which run at the same frequency, or possibly EMI or back currents from another source. Another possibility is the dual antenna that came supplied with the motherboard could be faulty. Either way it is not acceptable.

After much deliberation I decided to rectify the problem buy buying a USB Bluetooth 4.0 dongle and disabling the motherboard's on-board Bluetooth. This turned out to be problematic however as there were driver conflicts when installing the new drivers for the dongle. I disabled the on-board Bluetooth in the UEFI BIOS, but despite this the drivers and software suite supplied with the dongle were installing for the on-board Bluetooth. The net result was that the Bluetooth dongle was not recognized by its drivers and the bluetooth utility in the system tray was unable to activate bluetooth due to the on-board Bluetooth being disabled on a hardware level. Uninstalling the drivers and reverting to the default windows drivers did not yield results either. The dongle would be visible to my smartphone but would not connect as windows was not allowing incoming connections.

I made many frustrating attempts to fix this without success. I turned to a friend in the IT consolation industry to help me with the problem. With the aid of remote access via Teamviewer and a patched in data hotspot connection via a smartphone he was able to reconfigure the software and drivers for Bluetooth and restore full Bluetooth functionality to the system, all from sitting at his desk more than 30km away. Needless to say I was  impressed. 

After the bluetooth problem was solved we met in person to fix a few other things. including the the functionality of the FM radio system. The USB tuner dongle I chose is capable of much more than just FM radio, thanks to the powerful RTL232U tuner chip at its core. We installed a DVB-T tuner program on the computer to add the capability of digital TV to the computer. However due to ongoing driver issues and the non-TV optimized antenna on the vehicle this is a work in progress. 

A few other performance tweaks were made. We are planning further software tweaks to improve the ease of use of the system. More updates to follow. I would like to extend a huge thank you to  my friend for helping me with the project. 

As always, thanks for reading :). 

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