A2 Lite infrared carrier frequency

#1
Hello,
Doe's someone know which carrier frequency is used by A2 Lite infrared signal (power button) ?
Typical figures are 36, 38 or 56 kHz, I wonder which one is correct.
 
#2
Hello again,
For those interested here, I finally decided to measure this carrier frequency : it is 38 kHz. I hope the A2 power button is detected by typical IR receiver modules, like TSOP38438 for instance. I plan to test it soon ... i.e. less than 2 month ;-).
 
#3
Hello,
Here are some good news,

I took an IR Receiver (TSOP38438 as said), plugged it to my arduino and used IRrecvDumpV2 example taken in "IRremote" library. Thanks to the developers team and Mr "shirriff", by the way.

Here is the dumped result while pressing the A2 power button : "
Encoding : NEC
Code : 807F18E7 (32 bits)
Timing[67]:
+8950, -4450 + 600, -1650 + 600, - 550 + 600, - 550
+ 550, - 550 + 600, - 550 + 600, - 550 + 600, - 550
+ 600, - 500 + 600, - 550 + 600, -1650 + 600, -1650
+ 600, -1650 + 600, -1650 + 600, -1650 + 600, -1700
+ 550, -1700 + 550, - 550 + 600, - 550 + 600, - 550
+ 600, -1650 + 600, -1650 + 600, - 550 + 600, - 550
+ 550, - 550 + 600, -1650 + 600, -1650 + 600, -1650
+ 600, - 550 + 600, - 550 + 600, -1650 + 600, -1650
+ 600, -1650 + 600
unsigned int rawData[67] = {8950,4450, 600,1650, 600,550, 600,550, 550,550, 600,550, 600,550, 600,550, 600,500, 600,550, 600,1650, 600,1650, 600,1650, 600,1650, 600,1650, 600,1700, 550,1700, 550,550, 600,550, 600,550, 600,1650, 600,1650, 600,550, 600,550, 550,550, 600,1650, 600,1650, 600,1650, 600,550, 600,550, 600,1650, 600,1650, 600,1650, 600}; // NEC 807F18E7
unsigned int data = 0x807F18E7;
"
It seems to work, I now have to properly understand what it means ;-).
 
#4
With good documentation, understanding is straightforward.

NEC IR transmission protocol is documented here :
https://techdocs.altium.com/display/FPGA/NEC+Infrared+Transmission+Protocol
Thank you.

Decoding previous raw data gives :
Leading pulse burst + space
then 4 bytes (least significant bit first) :
1 0 0 0 0 0 0 0 : 0x01 address
0 1 1 1 1 1 1 1 : 0xFE not(address)
0 0 0 1 1 0 0 0 : 0x18 data
1 1 1 0 0 1 1 1 : 0xE7 not(data)

So the IR sends 0x18 data (to or from) 0x01 address
I have not tested the repetition behavior
 
#5
i undertand the concept.... I think you are trying (or you already have sucess) to use a2 lite remote control without a usb dongle . I am correct? Had you tried in a minix box?
I use mine a2 lite remote control but with a dongle.
Can you explain how can i use mine without usb dongle ? Do you know?

Thank you for your work ☺.
Is always good to know new things ☺

Ideal was using a2 lite remote control with all buttons working ☺
 
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#6
i undertand the concept.... I think you are trying (or you already have sucess) to use a2 lite remote control without a usb dongle . I am correct? Had you tried in a minix box?
I use mine a2 lite remote control but with a dongle.
Can you explain how can i use mine without usb dongle ? Do you know?

Thank you for your work ☺.
Is always good to know new things ☺

Ideal was using a2 lite remote control with all buttons working ☺
Only the power button uses IR. All other buttons require the dongle.
 
#8
Hello,

I confirm that only the power button uses IR, and only IR, i.e. the power button press is not detected by the usb (radio) dongle. All the other button press are detected by the usb dongle, and only it. So the dongle is still needed for the other operations ordered by the remote.

My goal is to use the power button to remotely turn on / off my box (not a MINIX one) via Ethernet (wake on lan, and so on), thru a home made circuit, another chapter, ... some work to do undoubtedly, but I agree it is fun to learn new things ;-).

And, by the way, I have tested the "repetition" behaviour. Continuous press onto the power button gives the following dumped result :
"
Encoding : NEC
Code : FFFFFFFF (0 bits)
Timing[3]:
+9000, -2150 + 650
unsigned int rawData[3] = {9000,2150, 650}; // NEC FFFFFFFF
unsigned int data = 0xFFFFFFFF;
"
repeated as long as the button is pressed.

Bye
 
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