PlainDSP M2M Communication Experimental Details This document describes the machine-to-machine (M2M) communication experiments using PlainDSP.

Transcription

1 1 PlainDSP M2M Communication Experimental Details This document describes the machine-to-machine (M2M) communication experiments using PlainDSP. Introduction The PlainDSP kit can be used to recognize frequency patterns, and therefore would be useful in M2M communication where audio signals are the exchanged energies. This same concept is used in many digital systems used in telecommunications and RF communication (e.g. frequency hopping). In this document we will learn how the PlainDSP kit can be utilized to acquire and process frequency patterns, and how this can translate into English text. Hello World! Contents Introduction... 1 Hardware... 2 Concept... 2 Experimentation... 4 Verify Channels... 4 Encoding... 9 Arduino Code Tone Sequence Generation Appendix... 18

2 Amplitude Amplitude Amplitude Amplitude Amplitude Amplitude 2 Hardware Here is what you ll need: 1. Computer with Arduino Software and USB cable 2. FL Studio Software (Demo version) 3. Arduino Uno 4. PlainDSP Audio Kit 5. m2m_comm.ino program 6. Hello World.wav file Concept There are many ways to accomplish this, but in this document a change in frequency will indicate a character. Frequency bands, or channels, will need to be allocated to distinguish the different letters. C 1 C 2 C 3 C 4 C n For example, a change from frequency channel C 1 to channel C 2 could indicate a letter A, or whatever we choose. In this experiment, an ID1 frequency (C ID1) and an ID2 frequency (C ID2) will be required to know when the character is being transmitted. The communication of the letter A is shown schematically: Frequency Time T1 Time T2 Time T3 Time T4 Time T5 CID1 CID2 C1 C2 CID1 CID2 C1 C2 CID1 CID2 C1 C2 CID1 CID2 C1 C2 CID1 CID2 C1 C2 Frequency Frequency Frequency Frequency Frequency Start Sequence Data Stop It is important to note that the available spectrum is finite. Thus, it is needed to calculate how much of the spectrum must be allocated to account for the number of transmittable characters. This means how much of the spectrum only one channel occupies should be known. As can be seen below, measurements from the PlainDSP show that approximately 333Hz of bandwidth are occupied for a single tone 880 Hz output.

3 3 The number of channels required for a total number of ASCII characters can now be calculated. The equation for this is the following: Total characters = (N 2) (N 3) where N is the number of total channels. Two channels are reserved for the packet identification, which is why we get the (N 2) term for the number of usable data channels. For each usable data channel, we are not allowed to use the two ID frequencies, nor are we have both data channels be the same frequency. This is why we get the (N 3) term. ASCII has a total of 256 characters, so that means we need a total of: 256 = (N 2) (N 3) = N 2 5N + 6 N = 5 ± ( 5)2 4(1)(6) 2(1) 19 This means we need 19 channels to encode all 256 ASCII characters. This might be too much, so instead we will chose 17, which gives us: Total Characters = (17 2) (17 3) = 210 characters This will cover the majority of useful characters to us, but may be limiting for other applications.

4 4 Experimentation This section discusses the experimentation, and how we verify what we calculated Verify Channels The code for this experiment is the example files PlainDSP_spectrum_plotter.ino and PlainDSP_main_frequency_plotter.ino. This first part uses the PlainDSP_spectrum_plotter.ino example program. A simple, free online tone generator was used to check the different channel frequencies. The website can be found here:

5 5 The channel frequency of interest was inputted in the application above and played over computer speakers. The PlainDSP_spectrum_plotter.ino file was uploaded on the Arduino and outputting frequency and amplitude information to the serial port. This information was copied and pasted into Microsoft Excel. A plot was generated in Excel to show the different frequency channels. This verifies that the channels can be separately recognized.

6 6 These calculated frequencies were then matched with a musical note frequency, or the closest frequency to that: Description Channel No. Caclulated Center Freq (Hz) Best Note Estimate (Hz) Error (Hz) Musical Note id 1 bit D5 chan A#5 chan D#6 chan G6 chan B6 id 2 bit C#7 chan E7 chan F#7 chan G#7 chan A7 chan B7 chan C8 chan D8 chan D#8 chan E8 chan F8 chan F#8 We do this only because the best audio frequency generators are musical things! Notice there is some error in our calculated bandwidths vs. the musical notes we chose: Hopefully this will be OK. In testing each of these channels, we find that there are some that are too close together:

7 7 So, we have to adjust the chosen frequencies: Description Channel No. Caclulated Center Freq (Hz) Best Note Estimate (Hz) Musical Note id 1 bit D5 chan A#5 chan D#6 chan G6 chan A#6 id 2 bit C#7 chan E7 chan F#7 chan G#7 chan A#7 chan C8 chan D8 chan E8 chan F#8 chan G8 chan G#8 chan A8

8 8 From which we obtain the following measurements: We can see there is less significant overlapping, however some does occur. This means that our communication will not be perfect, but it will work for now. We can see how we deviated from our original plan here: The original calculations are in blue, but we had to adjust our frequency selection from the 10 th channel on to avoid channel overlap.

9 9 Encoding Now that we have the audio channels in place, we can assign codes to the characters. This is a cumbersome process, but necessary. There are two data bits, so each two-pair code corresponds to a specific ASCII character. The number in each data field correspond to the channel detected by the PlainDSP. So, Having Data1=2 and Data2=3 means channel 2 (932 Hz) was detected first, and channel 3 (1245 Hz) was detected second. Data 1 Data 2 ASCII Symbol In Decimal Description 2 3 NULL 0 (Null character) 2 4 SOH 1 (Start of Header) 2 5 STX 2 (Start of Text) 2 7 ETX 3 (End of Text) 2 8 EOT 4 (End of Transmission) 2 9 ENQ 5 (Enquiry) 2 10 ACK 6 (Acknowledgement) 2 11 BEL 7 (Bell) 2 12 BS 8 (Backspace) 2 13 HT 9 (Horizontal Tab) 2 14 LF 10 (Line feed) 2 15 VT 11 (Vertical Tab) 2 16 FF 12 (Form feed) 2 17 CR 13 (Carriage return) 3 2 SO 14 (Shift Out) 3 4 SI 15 (Shift In) 3 5 DLE 16 (Data link escape) 3 7 DC1 17 (Device control 1) 3 8 DC2 18 (Device control 2) 3 9 DC3 19 (Device control 3) 3 10 DC4 20 (Device control 4) 3 11 NAK 21 (Negative acknowledgement) 3 12 SYN 22 (Synchronous idle) 3 13 ETB 23 (End of transmission block) 3 14 CAN 24 (Cancel) 3 15 EM 25 (End of medium) 3 16 SUB 26 (Substitute) 3 17 ESC 27 (Escape) 4 2 FS 28 (File separator) 4 3 GS 29 (Group separator) 4 5 RS 30 (Record separator) 4 7 US 31 (Unit separator) (Space) 4 9! 33 (Exclamation mark)

10 4 10 " 34 (Quotation mark ; quotes) 4 11 # 35 (Number sign) 4 12 $ 36 (Dollar sign) 4 13 % 37 (Percent sign) 4 14 & 38 (Ampersand) 4 15 ' 39 (Apostrophe) 4 16 ( 40 (round brackets or parentheses) 4 17 ) 41 (round brackets or parentheses) 5 2 * 42 (Asterisk) (Plus sign) 5 4, 44 (Comma) (Hyphen) (Dot, full stop) 5 9 / 47 (Slash) (number zero) (number one) (number two) (number three) (number four) (number five) (number six) (number seven) (number eight) (number nine) 7 4 : 58 (Colon) 7 5 ; 59 (Semicolon) 7 8 < 60 (Less-than sign) 7 9 = 61 (Equals sign) 7 10 > 62 (Greater-than sign ; Inequality) 7 11? 63 (Question mark) 7 64 (At sign) 7 13 A 65 (Capital A) 7 14 B 66 (Capital B) 7 15 C 67 (Capital C) 7 16 D 68 (Capital D) 7 17 E 69 (Capital E) 8 2 F 70 (Capital F) 8 3 G 71 (Capital G) 8 4 H 72 (Capital H) 8 5 I 73 (Capital I) 8 7 J 74 (Capital J) 8 9 K 75 (Capital K) 8 10 L 76 (Capital L) 10

11 8 11 M 77 (Capital M) 8 12 N 78 (Capital N) 8 13 O 79 (Capital O) 8 14 P 80 (Capital P) 8 15 Q 81 (Capital Q) 8 16 R 82 (Capital R) 8 17 S 83 (Capital S) 9 2 T 84 (Capital T) 9 3 U 85 (Capital U) 9 4 V 86 (Capital V) 9 5 W 87 (Capital W) 9 7 X 88 (Capital X) 9 8 Y 89 (Capital Y) 9 10 Z 90 (Capital Z) 9 11 [ 91 (square brackets or box brackets) 9 12 \ 92 (Backslash) 9 13 ] 93 (square brackets or box brackets) 9 14 ^ 94 (Caret or circumflex accent) 9 15 _ 95 (underscore, understrike, underbar or low line) 9 16 ` 96 (Grave accent) 9 17 a 97 (Lowercase a ) 10 2 b 98 (Lowercase b ) 10 3 c 99 (Lowercase c ) 10 4 d 100 (Lowercase d ) 10 5 e 101 (Lowercase e ) 10 7 f 102 (Lowercase f ) 10 8 g 103 (Lowercase g ) 10 9 h 104 (Lowercase h ) i 105 (Lowercase i ) j 106 (Lowercase j ) k 107 (Lowercase k ) l 108 (Lowercase l ) m 109 (Lowercase m ) n 110 (Lowercase n ) o 111 (Lowercase o ) 11 2 p 112 (Lowercase p ) 11 3 q 113 (Lowercase q ) 11 4 r 114 (Lowercase r ) 11 5 s 115 (Lowercase s ) 11 7 t 116 (Lowercase t ) 11 8 u 117 (Lowercase u ) 11 9 v 118 (Lowercase v ) w 119 (Lowercase w ) 11

12 11 12 x 120 (Lowercase x ) y 121 (Lowercase y ) z 122 (Lowercase z ) { 123 (curly brackets or braces) (vertical-bar, vbar, vertical line or vertical slash) (curly brackets or braces) 12 2 ~ 126 (Tilde ; swung dash) 12 3 DEL 127 (Delete) 12 4 Ç 128 (Majuscule C-cedilla) 12 5 ü 129 (letter "u" with umlaut or diaeresis ; "u-umlaut") 12 7 é 130 (letter "e" with acute accent or "e-acute") 12 8 â 131 (letter "a" with circumflex accent or "a-circumflex") 12 9 ä 132 (letter "a" with umlaut or diaeresis ; "a-umlaut") à 133 (letter "a" with grave accent) å 134 (letter "a" with a ring) ç 135 (Minuscule c-cedilla) ê 136 (letter "e" with circumflex accent or "e-circumflex") ë 137 (letter "e" with umlaut or diaeresis ; "e-umlaut") è 138 (letter "e" with grave accent) ï 139 (letter "i" with umlaut or diaeresis ; "i-umlaut") 13 2 î 140 (letter "i" with circumflex accent or "i-circumflex") 13 3 ì 141 (letter "i" with grave accent) 13 4 Ä 142 (letter "A" with umlaut or diaeresis ; "A-umlaut") 13 5 Å 143 (Capital letter "A" with a ring) 13 7 É 144 (Capital letter "E" with acute accent or "E-acute") 13 8 æ 145 (Latin diphthong "ae" in lowercase) 13 9 Æ 146 (Latin diphthong "AE" in uppercase) ô 147 (letter "o" with circumflex accent or "o-circumflex") ö 148 (letter "o" with umlaut or diaeresis ; "o-umlaut") ò 149 (letter "o" with grave accent) û 150 (letter "u" with circumflex accent or "u-circumflex") ù 151 (letter "u" with grave accent) ÿ 152 (Lowercase letter "y" with diaeresis) Ö 153 (letter "O" with umlaut or diaeresis ; "O-umlaut") 14 2 Ü 154 (letter "U" with umlaut or diaeresis ; "U-umlaut") 14 3 ø 155 (slashed zero or empty set) (Pound sign ; symbol for the pound sterling) 14 5 Ø 157 (slashed zero or empty set) (multiplication sign) 14 8 ƒ 159 (function sign ; f with hook sign ; florin sign ) 14 9 á 160 (letter "a" with acute accent or "a-acute") í 161 (letter "i" with acute accent or "i-acute") ó 162 (letter "o" with acute accent or "o-acute") 12

13 14 12 ú 163 (letter "u" with acute accent or "u-acute") ñ 164 (letter "n" with tilde ; enye) Ñ 165 (letter "N" with tilde ; enye) ª 166 (feminine ordinal indicator) º 167 (masculine ordinal indicator) (Inverted question marks) (Registered trademark symbol) (Logical negation symbol) 15 5 ½ 171 (One half) 15 7 ¼ 172 (Quarter or one fourth) (Inverted exclamation marks) 15 9 «174 (Angle quotes or guillemets) 15 10» 175 (Guillemets or angle quotes) (Box drawing character) (Box drawing character) Á 181 (Capital letter "A" with acute accent or "A-acute") 16 2 Â 182 (letter "A" with circumflex accent or "A-circumflex") 16 3 À 183 (letter "A" with grave accent) (Copyright symbol) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Cent symbol) (YEN and YUAN sign) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) 17 4 ã 198 (Lowercase letter "a" with tilde or "a-tilde") 17 5 Ã 199 (Capital letter "A" with tilde or "A-tilde") (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) (Box drawing character) 13

14 (Box drawing character) (generic currency sign) ð 208 (Lowercase letter "eth") Ð 209 (Capital letter "Eth") Arduino Code The Arduino code for detecting our protocol is complex, so it is not explained in detail here. Refer to the Appendix to see how the code works. Upload this code and follow the rest of these instructions to perform the M2M communication.

15 15 Tone Sequence Generation A difficult part of this is to use a tone sequence generator to transmit the message. In this experiment, FL Studio 11, a musical program, was used: I used the demo version, which cannot load saved files. It can, however, create and save FL studio files, and export the files to wav format. Here are some steps to begin with FL Studio 11: 1. Open FL Studio, and delete all of the current pattern instruments. 2. In the instruments panel on the left browse to Plugin presets > Generators > 3x Osc > Default, then click and drag that instrument to the pattern window

16 16 3. Now, Browse to View > Channel Settings, then click on the PLUGIN tab in the channel settings window. There are 3 oscillators shown with knobs. Turn the VOL setting fully CCW to leave only oscillator 1 working. This allows for a nice clean sine wave sound. 4. Click on View > Piano Roll

17 17 5. Let s make our first data packet! We will send the letter H to the PlainDSP. Click on D5 then C#7 for our IDs, then F#7 and G6 to designate H (since these correspond to the channels 8 and 4, respectively), then finally click on C#7 again to end the packet. Your audio message should look like the following below: 6. Make sure your PlainDSP is plugged in, running the Arduino code (found in the Appendix), the serial port is opened, and make sure the speakers are turned up. Press the triangular Play button and notice the H is displayed!

18 18 Appendix /* */ PlainDSP: Data Acquisition and Digital Signal Processing library Revision 1e Applicable license : This program and related paper documentation are owned by HL2 group SAS. The program is subject to the license GNU GPL version 3, which content is available in the file attached to this program. This license allows you to use, reproduce and adapt this program for private, educational, research purposes. If you intend to (i) use this program on a large scale and/or (ii) adapt this code, for COMMERCIAL PURPOSES, please contact HL2 at the following address : contact@hl2.fr in order to be granted a commercial license, subject to specific terms and conditions. /* Include libraries */ #include <PlainTLC5973x.h> #include <PlainDSP.h> /* Create objects */ PlainDSP DSP; PlainTLC5973x LED; /* Acquisition parameters */ const uint16_t _samples = 128; /* Max value depends upon available memory space */ const float _samplingfrequency = ; /* From Hz to 80 khz */ const uint16_t _defadcchannel = 0; /* From 0 to 5 on ATmega328 powered Arduino */ const uint16_t _refvoltage = DSP_REF_VOL_EXTERNAL; /* External: 3.3V */ const uint8_t _options = (DSP_OPT_DIS_TIM_0 DSP_OPT_DIS_TIM_2 DSP_OPT_NOI_CANCELLER); /* Display parameters */ uint8_t _maxledintensity = 0xFF; /* User parameters (John Pritchard, 2014) */ int packet[4]; //for recording incoming data packet int prev_packet[4]; //for storing temporary packet data (used for shifting) int p_len = 4; //packet length int tstart = 0; //timer start int idflag1 = 0; //data id flag 1 int idflag2 = 0; //data id flag 2 int timeout = 400; //timeout in ms int thresh = 200; //noise threshold int chan2inuseflag = 0; //flag for channel usage; int chan3inuseflag = 0; //flag for channel usage; int chan4inuseflag = 0; //flag for channel usage; int chan5inuseflag = 0; //flag for channel usage; int chan7inuseflag = 0; //flag for channel usage; int chan8inuseflag = 0; //flag for channel usage; int chan9inuseflag = 0; //flag for channel usage; int chan10inuseflag = 0; //flag for channel usage; int chan11inuseflag = 0; //flag for channel usage; int chan12inuseflag = 0; //flag for channel usage; int chan13inuseflag = 0; //flag for channel usage; int chan14inuseflag = 0; //flag for channel usage; int chan15inuseflag = 0; //flag for channel usage; int chan16inuseflag = 0; //flag for channel usage; int chan17inuseflag = 0; //flag for channel usage; int data1 = 0; //data byte, will contain either 2-5 or 7-17, depending on what channel is detected. int data2 = 0; //data byte, will contain either 2-5 or 7-17, depending on what channel is detected. void setup(void) {

19 19 /* Initialize serial comm port */ Serial.begin(115200); /* Set data acquisition parameters */ DSP.SetAcquisitionEngine(_defAdcChannel, _refvoltage, _samplingfrequency, _samples, _options); /* Initialize internal LED driver */ LED.Init(PINB5, &PORTB, DEV_TYP_TLC5973); void loop(void) /* This function repetitively prints lines containing time, major frequency position, major frequency height in semi-colon separated fields. */ { //Blink(); /* Select the optimal amplifying stage and apply gain */ AutoRanging(); /* Null offset */ DSP.ResetOffset(); /* Weight data */ DSP.Windowing(DSP_WIN_TYP_HANN, DSP_FORWARD); /* Compute FFT */ DSP.ComputeForwardFFT(); /* Compute amplitudes */ DSP.ComplexToReal(DSP_SCL_TYP_AMPLITUDE); /* Find major peak */ struct strpeakproperties majorpeak; DSP.MajorPeak(&majorPeak); /* Compute interpolated values */ struct strpeakproperties interpolatedpeak; DSP.InterpolatedPeak(majorPeak.position, &interpolatedpeak); floor < 687){ < 2318){ if(interpolatedpeak.height > thresh){ //check if detected signal is above the noise //Check if start id 1 (chan 1) frequency detected if(!idflag1 &&!idflag2 && interpolatedpeak.position > 487 && interpolatedpeak.position idflag1 = 1; // set the idflag1 tstart = millis(); // successful detection, so restart the timer //Check if start id 2 (chan 6) frequency detected if(idflag1 &&!idflag2 && interpolatedpeak.position > 2118 && interpolatedpeak.position idflag2 = 1; // set the idflag2 tstart = millis(); // successful detection, so restart the timer //If both start id's detected, look for and store data (look for the different channels if(idflag1 && idflag2){ if(interpolatedpeak.position > 832 && interpolatedpeak.position < 1032 &&!chan2inuseflag){ //chan 2 chan2inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 2; //put in data1 if not full, otherwise put in data2 else{data2 = 2; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 1145 && interpolatedpeak.position < 1345 &&!chan3inuseflag){ //chan 3 chan3inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 3; //put in data1 if not full, otherwise put in data2 else{data2 = 3; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 1468 && interpolatedpeak.position < 1668 &&!chan4inuseflag){ //chan 4 chan4inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 4; //put in data1 if not full, otherwise put in data2

20 20 else{data2 = 4; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 1765 && interpolatedpeak.position < 1965 &&!chan5inuseflag){ //chan 5 chan5inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 5; //put in data1 if not full, otherwise put in data2 else{data2 = 5; tstart = millis(); // successful detection, so restart the timer else if(idflag1 &&!idflag2 && interpolatedpeak.position > 2118 && interpolatedpeak.position < 2318){ //chan 6, Stop id, if this one detected within this nested if statement, comm has ended rstcomm(); else if(interpolatedpeak.position > 2537 && interpolatedpeak.position < 2737 &&!chan7inuseflag){ //chan 7 chan7inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 7; //put in data1 if not full, otherwise put in data2 else{data2 = 7; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 2860 && interpolatedpeak.position < 3060 &&!chan8inuseflag){ //chan 8 chan8inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 8; //put in data1 if not full, otherwise put in data2 else{data2 = 8; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 3222 && interpolatedpeak.position < 3422 &&!chan9inuseflag){ //chan 9 chan9inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 9; //put in data1 if not full, otherwise put in data2 else{data2 = 9; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 3629 && interpolatedpeak.position < 3829 &&!chan10inuseflag){ //chan 10 chan10inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 10; //put in data1 if not full, otherwise put in data2 else{data2 = 10; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 4086 && interpolatedpeak.position < 4286 &&!chan11inuseflag){ //chan 11 chan11inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 11; //put in data1 if not full, otherwise put in data2 else{data2 = 11; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 4599 && interpolatedpeak.position < 4799 &&!chan12inuseflag){ //chan 12 chan12inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 12; //put in data1 if not full, otherwise put in data2 else{data2 = 12; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 5174 && interpolatedpeak.position < 5374 &&!chan13inuseflag){ //chan 13 chan13inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 13; //put in data1 if not full, otherwise put in data2 else{data2 = 13;

21 21 tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 5820 && interpolatedpeak.position < 6020 &&!chan14inuseflag){ //chan 14 chan14inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 14; //put in data1 if not full, otherwise put in data2 else{data2 = 14; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 6172 && interpolatedpeak.position < 6372 &&!chan15inuseflag){ //chan 15 chan15inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 15; //put in data1 if not full, otherwise put in data2 else{data2 = 15; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 6545 && interpolatedpeak.position < 6745 &&!chan16inuseflag){ //chan 16 chan16inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 16; //put in data1 if not full, otherwise put in data2 else{data2 = 16; tstart = millis(); // successful detection, so restart the timer else if(interpolatedpeak.position > 6940 && interpolatedpeak.position < 7140 &&!chan17inuseflag){ //chan 17 chan17inuseflag = 1; //set channel in use once detected. if(data1 == 0){data1 = 17; //put in data1 if not full, otherwise put in data2 else{data2 = 17; tstart = millis(); // successful detection, so restart the timer if(tdiff(tstart) > timeout){ rstcomm(); /* TEST - Detect center frequency of 600 Hz if(interpolatedpeak.height > 500){ //check if above the noise floor if(interpolatedpeak.position > 550 && interpolatedpeak.position < 650){ Blink(); */ /* TEST - Print results Serial.print((millis() / ), 3); Serial.print(', '); Serial.print(interpolatedPeak.position, 2); Serial.print(', '); Serial.print(interpolatedPeak.height, 2); Serial.println(); //Blink(); //delay(250);*/ uint8_t AutoRanging(void) /* Select optimal range for actual signal level, read from analog ports A0, A1 and A2 */ { float vgains[] = {100.0, 10.0, 1.0; uint8_t adcchannel = 3; do { adcchannel -= 1; /* Set channel */ DSP.Channel(adcChannel); /* Acquire data from selected channel */ DSP.GetScanData(); while (((DSP.Min() < 10.0) (DSP.Max() > )) && (adcchannel!= 0)); /* Apply gain */

22 22 DSP.Gain(vGains[adcChannel]); return(adcchannel); void Blink(void) { /* Create and initialize the state the first time */ static uint8_t state = 0x00; /* invert each time */ state = ~state; if (state) { LED.SendData(0, _maxledintensity, 0); else { LED.SendData(0, 0, 0); int tdiff(int strt){ return millis() - strt; void rstcomm(){ //report data before reset report(); //reset data tstart = 0; idflag1 = 0; idflag2 = 0; data1 = 0; data2 = 0; chan2inuseflag = 0; chan3inuseflag = 0; chan4inuseflag = 0; chan5inuseflag = 0; chan7inuseflag = 0; chan8inuseflag = 0; chan9inuseflag = 0; chan10inuseflag = 0; chan11inuseflag = 0; chan12inuseflag = 0; chan13inuseflag = 0; chan14inuseflag = 0; chan15inuseflag = 0; chan16inuseflag = 0; chan17inuseflag = 0; /* the report() function is a lookup table with most of the ascii codes (up to 211). When the two data bits (data1 and data2) are full, they will be checked against this lookup table to determine the message sent. For example, when data1=2 and data2=14, Serial.write(10) will be called. This writes the ascii code 10 (decimal) to the serial port, which corresponds to a "new line" command.*/ void report(){ if(data1!= 0 && data2!= 0){ if(data1 == 2){ if(data2 == 3){ Serial.write(0); else if(data2 == 4){ Serial.write(1); else if(data2 == 5){ Serial.write(2); else if(data2 == 7){ //make sure data is not empty

23 23 Serial.write(3); else if(data2 == 8){ Serial.write(4); else if(data2 == 9){ Serial.write(5); else if(data2 == 10){ Serial.write(6); else if(data2 == 11){ Serial.write(7); else if(data2 == 12){ Serial.write(8); else if(data2 == 13){ Serial.write(9); else if(data2 == 14){ Serial.write(10); else if(data2 == 15){ Serial.write(11); else if(data2 == 16){ Serial.write(12); else if(data2 == 17){ Serial.write(13); else if(data1 == 3){ if(data2 == 2){ Serial.write(14); else if(data2 == 4){ Serial.write(15); else if(data2 == 5){ Serial.write(16); else if(data2 == 7){ Serial.write(17); else if(data2 == 8){ Serial.write(18); else if(data2 == 9){ Serial.write(19); else if(data2 == 10){ Serial.write(20); else if(data2 == 11){ Serial.write(21); else if(data2 == 12){ Serial.write(22); else if(data2 == 13){ Serial.write(23); else if(data2 == 14){ Serial.write(24); else if(data2 == 15){ Serial.write(25); else if(data2 == 16){

24 24 Serial.write(26); else if(data2 == 17){ Serial.write(27); else if(data1 == 4){ if(data2 == 2){ Serial.write(28); else if(data2 == 3){ Serial.write(29); else if(data2 == 5){ Serial.write(30); else if(data2 == 7){ Serial.write(31); else if(data2 == 8){ Serial.write(32); else if(data2 == 9){ Serial.write(33); else if(data2 == 10){ Serial.write(34); else if(data2 == 11){ Serial.write(35); else if(data2 == 12){ Serial.write(36); else if(data2 == 13){ Serial.write(37); else if(data2 == 14){ Serial.write(38); else if(data2 == 15){ Serial.write(39); else if(data2 == 16){ Serial.write(40); else if(data2 == 17){ Serial.write(41); else if(data1 == 5){ if(data2 == 2){ Serial.write(42); else if(data2 == 3){ Serial.write(43); else if(data2 == 4){ Serial.write(44); else if(data2 == 7){ Serial.write(45); else if(data2 == 8){ Serial.write(46); else if(data2 == 9){ Serial.write(47); else if(data2 == 10){ Serial.write(48);

25 25 else if(data2 == 11){ Serial.write(49); else if(data2 == 12){ Serial.write(50); else if(data2 == 13){ Serial.write(51); else if(data2 == 14){ Serial.write(52); else if(data2 == 15){ Serial.write(53); else if(data2 == 16){ Serial.write(54); else if(data2 == 17){ Serial.write(55); else if(data1 == 7){ if(data2 == 2){ Serial.write(56); else if(data2 == 3){ Serial.write(57); else if(data2 == 4){ Serial.write(58); else if(data2 == 5){ Serial.write(59); else if(data2 == 8){ Serial.write(60); else if(data2 == 9){ Serial.write(61); else if(data2 == 10){ Serial.write(62); else if(data2 == 11){ Serial.write(63); else if(data2 == 12){ Serial.write(64); else if(data2 == 13){ Serial.write(65); else if(data2 == 14){ Serial.write(66); else if(data2 == 15){ Serial.write(67); else if(data2 == 16){ Serial.write(68); else if(data2 == 17){ Serial.write(69); else if(data1 == 8){ if(data2 == 2){ Serial.write(70);

26 26 else if(data2 == 3){ Serial.write(71); else if(data2 == 4){ Serial.write(72); else if(data2 == 5){ Serial.write(73); else if(data2 == 7){ Serial.write(74); else if(data2 == 9){ Serial.write(75); else if(data2 == 10){ Serial.write(76); else if(data2 == 11){ Serial.write(77); else if(data2 == 12){ Serial.write(78); else if(data2 == 13){ Serial.write(79); else if(data2 == 14){ Serial.write(80); else if(data2 == 15){ Serial.write(81); else if(data2 == 16){ Serial.write(82); else if(data2 == 17){ Serial.write(83); else if(data1 == 9){ if(data2 == 2){ Serial.write(84); else if(data2 == 3){ Serial.write(85); else if(data2 == 4){ Serial.write(86); else if(data2 == 5){ Serial.write(87); else if(data2 == 7){ Serial.write(88); else if(data2 == 8){ Serial.write(89); else if(data2 == 10){ Serial.write(90); else if(data2 == 11){ Serial.write(91); else if(data2 == 12){ Serial.write(92); else if(data2 == 13){ Serial.write(93);

27 27 else if(data2 == 14){ Serial.write(94); else if(data2 == 15){ Serial.write(95); else if(data2 == 16){ Serial.write(96); else if(data2 == 17){ Serial.write(97); else if(data1 == 10){ if(data2 == 2){ Serial.write(98); else if(data2 == 3){ Serial.write(99); else if(data2 == 4){ Serial.write(100); else if(data2 == 5){ Serial.write(101); else if(data2 == 7){ Serial.write(102); else if(data2 == 8){ Serial.write(103); else if(data2 == 9){ Serial.write(104); else if(data2 == 11){ Serial.write(105); else if(data2 == 12){ Serial.write(106); else if(data2 == 13){ Serial.write(107); else if(data2 == 14){ Serial.write(108); else if(data2 == 15){ Serial.write(109); else if(data2 == 16){ Serial.write(110); else if(data2 == 17){ Serial.write(111); else if(data1 == 11){ if(data2 == 2){ Serial.write(112); else if(data2 == 3){ Serial.write(113); else if(data2 == 4){ Serial.write(114); else if(data2 == 5){ Serial.write(115); else if(data2 == 7){

28 28 Serial.write(116); else if(data2 == 8){ Serial.write(117); else if(data2 == 9){ Serial.write(118); else if(data2 == 10){ Serial.write(119); else if(data2 == 12){ Serial.write(120); else if(data2 == 13){ Serial.write(121); else if(data2 == 14){ Serial.write(122); else if(data2 == 15){ Serial.write(123); else if(data2 == 16){ Serial.write(124); else if(data2 == 17){ Serial.write(125);