Build Log – DIY CAR PC / Car entertainment system – GPS and Amplifier

I bought a GPS module from aliexpress, it has very small footprint and has NEO-6M module as a receiver with tiny antenna. Also bought a SERIAL (TTL RS232) to USB converted based on PL2303 converter and removed the header pins on it. After going through different schemes about how i’m going to mount these over another ( The pin sequence in these modules matches surprisingly),finally i used a strap of wires and connected both the modules. .


GPS Module

GPS Module

BTW, the GPS module works on 5VDC, as it has a 3.3v regulator on board. When tested using a softwareVisualGPSXP” on my Laptop, the GPS seems to be working good.


A decent power for CAR entertainment system would be at least 20W RMS with four channels. There are number of ICs available on Ebay from “TDA” series alongwith readymade boards and other stuff like input selection, denoiser and tone control. I decided to make the board myself and chose TDA7650 as a amplifier IC. Theoretically it can deliver 50W into 2 Ohm load, but that is a maximum limit. I don’t want the amplifier to stress out and scream. Myself and my Family prefers less noisy music and i feel 30W RMS per channel is a reasonable power even when somebody wants to dance with CAR doors open. .

Unlike conventional rotary knob with switch beneath, i will be using push buttons for volume control, as it saves me from creating a base plate to fit the potentiometer and in my opinion the rotary knob looks ugly. So i will be using PT2257 digital volume control. An Atmega88 based shutdown controller will monitor all the buttons and will send the appropriate signals to PT2257, Cubieboard and SMPS.

Following is a PCB i designed for this amplifier. I will post the update soon once it is tested for first time..

Here is a zip archive containing Amplifier PCB and PDF files for toner transfer.


Following are the links to GPS module and RS232 to USB converter sellers.




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