Monday, August 8, 2016

Improving TX3 Pro Amlogic S905X Android box's IR remote sensitivity

TX3 Pro is a decent and affordable Android box based on Amlogic S905X.  Unlike many other cheap Android boxes, this box does have an window for the IR receiver.  Its IR sensitivity turned out to be indeed better than Tronsmart S95 Pro's, which is horrible due to the poor IR transmission of the body and lack of IR receiving window (you can drill a hole and replace the receiver with a decent one).  However, it is still not as good as I expected.  For example, it cannot detect IR reflection from the ceiling, which decent IR receivers with a proper window can handle.

I tried to align the IR receiver with the window as much as possible, but no noticeable improvement was seen.  So, I replaced the IR receiver with Vishay TSOP34438, which is pin compatible with the original. The legs of the receiver need to be bent so the receiving dome touches the IR window when the board is mounted on the case.  Now I can point the remote at the ceiling and the box still recognizes the signal with no problem - SUCCESS.

By the way, the IR remote control can be easily customized by editing /system/etc/remote.conf which has a mapping table from IR code to Linux key code (not Android key code!).  Here is a nice Linux key code table along with Android key code.  If remote.conf keeps being overwritten by the default one at reboot, make it readonly with chmod so it won't be overwritten.

IR window

Motherboard with the new IR receiver

New IR receiver

 
Original IR receiver