| Electronics > Beginners |
| Infrared frequency heater remote |
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| max246:
I am trying to hack my heater and re-produce the infrared signal of the 6 buttons, but it seems a bit odd how to decode this sort of stuff. I used an arduino sketch which allow me to read and repeat the codes and it worked with different remote controller but not for this specifi one. The board is powered by a button battery and it only has a chip BEC5104S, I have even soldered a infrared emitter that does 38Khz so I think it is running at 38khz the signal. After testing here and there I was aim to test on the oscilloscope and send raw signals but still not success. I attach here some pictures and hopefully someone cal help me out to figure out what frequency is running and how to send raw codes via an arduino. |
| alsetalokin4017:
Well, that shouldn't be too hard. Just eyeballing your scope trace I see short HI pulses of about 400 microseconds and long pulses of three times that length, and separated by one or three LO periods of 400 us also. So use the scope to zoom in on one of the short pulses and measure it accurately, then program the Arduino to send the sequence of pulses of the appropriate lengths to a regular IR LED (or the 38 MHz transducer), which will be multiples of the basic short pulse duration you measured accurately using the scope. Then to get the appropriate repetition rate of the pulse train from the remote, zoom the scope out so that you can see several instances and measure the interval between them. I have used this method to control my window AC unit. |
| alsetalokin4017:
So the pulse train in the scopeshot above may be represented by the following string: 111011101000111011101000100010001110100010001 where the basic time unit is "about" 400 microseconds and where 1 means HI and 0 means LO and a sequence like "111" means a HI pulse of 3x units duration. |
| t1d:
I am noobish, so this may not help... This type of inexpensive Logic Analyzer has a good reputation, for a Chinese gizmo... Download Saleae's Sigrock and PulseView, to use it with a laptop. They're freeware. YouTube has really good instructionals, about it. https://www.ebay.com/itm/USB-Logic-Analyzer-Device-Set-Compatible-to-Saleae-24MHz-8CH-for-ARM-FPGA-M100/223119091948?hash=item33f2ef28ec:g:NNoAAOSwjXVaoiyH:rk:8:pf:0 |
| hexreader:
The Chinese version of BEC5104S datasheet is just readable enough to be able to easily decode your scope trace as 110110001000 Try different buttons to see what codes they produce. As far as I can tell, that chip produces unmodulated signals. Remote controls usually need modulation. Maybe the modulation is done elsewhere on your remote control. I cannot tell. Just adding an IR LED to that signal won't help. Put scope probe directly onto the remote control's IR LED (the original one, not the one that you added) to check modulated signal, assuming that it is modulated at all. |
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