This script convert to wav file from the rawcode of mode2 command(lirc). It made for CHIP. but it can work any env. maybe.
| item | descriptions |
|---|---|
| RATE | output file sampling rate[Hz] |
| BIT | output file bit depth |
| SOX_CMD | sox command path |
execute with two arg that is input_file_name and output_file_name
[yourmachine]% ./rawcode2wav.sh ./inputfile.txt ./outputfile.wav
play a wav file.
[yourmachine]% aplay ./outputfile.wav
Playing WAVE 'outputfile.wav' : Signed 24 bit Little Endian in 3bytes, Rate 192000 Hz, Stereo
- sox
- bash
- egrep / fgrep / sed
- bc
Note: this script generate a very long command line. it is restricted by ARG_MAX.
[yourmachine]% getconf ARG_MAX
2097152
- C.H.I.P. or any env?
- IR-LEDs (2 LEDs required)
CHIP
--------
| |
| HP L----------------------------------
| | |
| HP R-----||------*---[ IR LED |>| ]---*
| | C1 | |
-------- ---[ |<| IR LED ]---
: corner/cross-over
* : connect
HP L/R : audio output Left/Right
C1 : 1uF or less
CHIP IR receiver
-------- ---------
| | | |
| VCC-5V-------VCC OUTPUT---
| | | | |
| GND---*---GROUND | |
----MIC IN | | | | |
| -------- | --------- |
| | [R1]
| | |
| | *----
| | | |
| | [R2] |
| | | |
| ----------------- |
| |
----------------------------------[C1]--
: corner/cross-over
* : connect
R1 : 100k Ohm
R2 : 560 Ohm
C1 : 1 uF or less
R1 and R2 is needed to avoid input saturation/clipping. it's very important for stabilise a mode2.
https://bbs.nextthing.co/t/installing-lirc-on-c-h-i-p/2449/5
https://web.archive.org/web/20180602133626/https://bbs.nextthing.co/t/installing-lirc-on-c-h-i-p/2449
# install tools
[yourmachine]% sudo apt-get install lirc bc sox
# get RAW_CODES
[yourmachine]% sudo mode2 -H audio_alsa -d default | tee inputfile.txt
space 765
pulse 127
space 214
pulse 80
space 1208273
pulse 2624
space 2658
<snip>
pulse 852
space 1895
pulse 831
space 809
pulse 855
^C <--- Ctrl-C to exit
# convert to wav
[yourmachine]% ./rawcode2wav.sh ./inputfile.txt outputfile.wav
/usr/bin/sox WARN sox: `outputfile.wav' output clipped 46 samples; decrease volume?
# IR transmit
[yourmachine]% aplay outputfile.wav
Playing WAVE 'outputfile.wav' : Signed 24 bit Little Endian in 3bytes, Rate 192000 Hz, Stereo
sox said anything, it's ok. It's using a sine wave with max amplitude.
- Edit a RAW_CODES to only a sequence of IR code, before convert. it's appear between leader-code and long space.
- Edit a RAW_CODES to acutual format of NEC-format, AEHA-format or SONY-format.