how Connect Sparkfun BT to a BT bracelet?

Well i trying to connect betwen Sparkfun Blue Smirft BT and a BT bracelte, here is the Bracelet that i am using: I can discover the bracelet but once i try to connect its returns "connect failed", the BT itself is working. i made successfully connection between my Android phone and bracelet and also i can connect between two Sparkfun BT.  thanks for help. i hope i wrote it in the right spot :P.

Question by RioC2   |  last reply

My rc channel!

Id just thought id let you friendly bunch know of a new channel ive just creaated for anything rc related. Feedback welcome! Thanks :) Sharlston

Topic by sharlston 

PS/2 F to DB9 F adapter

Hi. I have been looking all over for some good info on making an PS/2 F to a DB9 F is going to connect to my Magnetic card reader that has a PS/2 M. any wiring diagrams or any thing like that would help thanksOK i did find this but what dose it meen when it say's 3-------------------3,94-------------------2,5,7 dose that meen that i have to solder a wire to pin 3 on the mini din and with the same wire put it to 3 and 9 like bridging them together? Mouse adapter for PS/2 mouse to Serial DB-9 Port.These work on only mouses that are dual type.Female PS/2 Mini-DIN 6 to Female DB-9Wiring FormatMiniDin-6 F ------ DB-9 F1-------------------13-------------------3,94-------------------2,5,75-------------------6G-------------------G

Topic by tugmyroo 

How to construct a U.F.O?

Question by mestes66   |  last reply

How do you stage composit rocket engines? Answered

I am building a rocket and i want to use two or so F engines, how do i stage these

Question by peoplerstupid   |  last reply

1958 Walz Direct F:Stop Meter

I just thought I would share this cool '58 F:Stop meter I bought at a second-hand store for 50 cents. If anyone has information about this, (value maybe...) it would be nice.

Topic by ItsTheHobbs 

how does one build a electromagnetic blast device that knocks out electrical implants in the human body Answered

Electrical implants were put into my body without my permission,they inflict pain at strategic points in the body there small enought to be inserted with a needle..can they be neutralize electronicly..dennis o'donnell,, #6317890140

Question by woo6dy   |  last reply

Help with what they are? Answered

its in the pic is it a regulator and what brand is the F

Question by MACKattacksnipe   |  last reply

help using audacity!

I need help to strip the words of a song so i just have a beat. can anybody help me out plz. 

Question by 2hot2hack   |  last reply

how do i fix this minecraft bug? Answered

Theres been a bug going on in minecraft that is hard to fix.its a bug that,when you fly to much in creative, it glitches up and when you try to exit it keeps the cursor inside the box. its happened to me twice and when it does, you cant go to any other websites or anything. you cant type in anything and if you sign out of gmail (or any other mail site) it wont let you back on unless you type both the username and password. thanks for helping.                       nfk11

Question by nfk11   |  last reply

How to fix jammed Dvd/Cd drive F?

First my drive did not open so I repaired it using the paperclip method BUT did not turn off the PC. Now every time I boot up, the drive makes a repetitive jerking sound and I have to push in the already closed drive to make the noise stop and enable the  PC to boot.  IS there something I can do to fix it? Tks

Question by perdu1   |  last reply

Secret spy image photo copying batch file

Good Afternoon All.I am wondering if someone could assist me in tweaking an excellent batch file. Below is a line of code I wish to change:for /f "tokens=* delims= " %%f in ('dir/b/s/a-d c:\*.%%a') do (What I would like to do is have the file back up images from the current user profile rather than the entire Hard Drive. I have tried the following combinations with no success:for /f "tokens=* delims= " %%f in ('dir/b/s/a-d %USERPROFILE%\*.%%a') do (set location=%USERPROFILE%for /f "tokens=* delims= " %%f in ('dir/b/s/a-d %location%\*.%%a') do (for /f "tokens=* delims= " %%f in (%USERPROFILE%\*.%%a') do (I would be very greatful for any assistance.Regards,Daniel

Topic by daniel.penning   |  last reply

What should i do with a pda and a old scanner? Answered

Good day Instructables :)    I have a old Acer Scanner 620 (flatbed scanner) and a pda. the old scanner is too old to be compatible (remember that parallel port is dead long time ago) and the pda has a broken On button and the battery is damage. What should i use these materials for?    What can i do with them? Should i turn them into a spy camera (but i don't how to do that...) or something like that? I want to use them for something besides throwing into the rubbish Please help? Here are the photos of the pda and the scanner:=

Question by Peter5465   |  last reply

Help please! Repairing trip-up!

Please Help!!! I need help to fix my telephone's mic! I have a telephone at home that was dropped many times and ultimately finished breaking something (e.i. the microphone) so while me being an aspirating electronic engineer (NOOB!) I tried to open up the phone and change the mic with a solution that I thought pretty smart; I learn some time ago that if you change the polarity of a speaker, you can use it as a mic so I naturally opened up the phone and to my surprise I find 2 freaking mics that look nothing like a speaker (or even a freaking mic for that matter) (Picture below). So I was asking myself... Can someone help me to change the mics in the phone with the speaker (Picture of the speaker below, any of the speakers are ok), by telling me about any changes that I have to do or any alert that this might not work (keep in to consideration the voltage, speaker type, and the polarity)... P.S. â€‹II was also thinking about changing the antenna because it's pretty weak!(Pics below). Any thoughts about that? And Thank You! Sincerely; Your hopefully future friend and companion: AntF

Topic by AntF   |  last reply

Most efficient way to recover heat from 130 degree F water and transfer this heat to 140 degree F water?

I am making a solar still and I need to recover as much heat as I can from the 130 degree F water (bringing the water temp down to near ambient, 72 degrees F) and then transfer this heat to 140 degree F seawater. I have a limited amount of solar collectors to heat brackish water, send it through an evaporator tower and then a condenser tower to make fresh water. As the fresh water goes through the condenser it gains a great deal of latent heat, thus the 130 degree F water. In order to increase production and regain otherwise lost energy I am trying to recapture a portion of this heat to further warm up the brackish water (currently at 140 degrees after exiting the evaporator tower) before being further heated with the solar collectors. I am operating off grid, so the solution must utilize solar heat or PV panels as the power source.  Does anyone know of a heat pump that operates best in this temp range? What about using TEC (aka TEG, TEP or TEHP) to perform this task? Is there a better or more obvious solution that I am oblivious to? Any advice would be much appreciated. 

Question by MichaelMichael   |  last reply

Parallel beam of light out of biconvex lens f=45mm

Hi, I would like to create an almost parallel beam of light with an LED and a biconvex lens. Therefore I have to place the LED directly in the focal point. I thought of a setup with a PVC pipe with threading: I could glue the lens to one end and screw a cap onto the other. Then I would drill a hole in the middle of the cap and stick the LED through the hole. By screwing the cap back and forth on the PVC pipe I would be able to find the exact focal point and then fix the cap in place. There is just one problem: Lenses are either incredibly expensive or only available as sets. The only exception I found so far are lenses for google cardboard. They sell for just a few euros on ebay. Google cardboard lenses have a focal length of 45mm and different diameters, I would like to use a diameter of 25mm which is no problem. Now I wonder: Is the focal length of 45mm too small ? Will I be able to get an (almost) parallel beam of light out of this setup ? The LED is no ideal point light source. Originally I wanted to get f>80mm but that is really expensive. Anyone with experience on this kind of setup ? Tips you could share ? Can I get this to work, or will the approach be too unprecise.

Topic by mintwurm   |  last reply

Multiple Keyboards

I would like to know if there is a way to hook up two keyboards and run them simultaneously but doing different things i.e. the "f" key types and f using one keyboard but say opens firefox on the other. Any Ideas would be appreciated

Topic by PlainsPrepper   |  last reply

Pentium 4 CPU hitting 75+ Degrees C (167 Degrees F)

Hi It's the good old Aussie summer and my computer doesn't like it one bit. Does anyone think a Pentium 4 CPU getting up to 75+ Degrees C (167 Degrees F) is a bit hot? The case only has only one case fan (in the power supply) Any suggestions to get it to run cooler? More fans? Water cooling?

Topic by thermoelectric   |  last reply

verilog code ?

I have made sample code for 4 bit ALU and 3 to 8 decoder to make 4 bit processor . as designer we can design anything so I have started to design processor with two function ALU and decoder 4 bit alu Module alu (a,b,s0,s1,s2 f); Input a,b,s0,s1,s2; Output f; Reg [3:0]; Always @(s0,s1,s2); Begian Case (s0,s1,s2); 3b’000 :f=(a&b;); 3b’001:f= (a|b); 3b’010 :f= ~(a&b;); 3b’011 :f= ~ (a|b); 3b’100:f=(a^b); 3b’101: f=(a*b); 3b’110: f=(a+b); 3b’111:f=(a-b ); End case End module 3to 8 decoder Module decoder (a2,a1,a0, d7,d6,d5,d4,d3,d2,d1,d0); Input a2,a1,a0; Output d7,d6,d5,d4,d3,d2,d1,d0; Wire [7:0]; Always @(a2,a1,a0); Begin Case (a2,a1,a0); 4’b000:( d7,d6,d5,d4,d3,d2,d1,d0)=00000001; 4’001: (d7,d6,d5,d4,d3,d2,d1,d0)=00000010; 4’b010: (d7,d6,d5,d4,d3,d2,d1,d0)=00000100; 4’b011: (d7,d6,d5,d4,d3,d2,d1,d0)=00001000; 4’b100:( d7,d6,d5,d4,d3,d2,d1,d0)=00010000; 4’b101:( d7,d6,d5,d4,d3,d2,d1,d0)=00100000; 4’b110: (d7,d6,d5,d4,d3,d2,d1,d0)=01000000; 4’b111: (d7,d6,d5,d4,d3,d2,d1,d0)=10000000; Endcase Endmodule I don't understand how to connect 4 bit Alu with     3 to 8 bit decoder to make 4 bit processor    

Question by vead   |  last reply

Convert DS18B20 temperature to string?

I want to convert DS18B20 temperature (4-bytes code from datasheet) to string with accuracy 0.1°C (like sprintf %.1f). AVR. C language (avr-gcc). I need for small code, so sprintf, floating-point types and round from math.h is bad idea. My following current code is bad also: This is the date sheet of DS18B20 void reverse_string(char *s) {     char *p, c;     for (p = s + strlen(s) - 1; s <= p; ++s, --p) {         c = *p;         *p = *s;         *s = c;     } } void ts_to_string(uint16_t ts, char *s) {     int8_t n = (int8_t)(ts >> 4);     uint8_t neg = n & 0x80;     char *p = s;     float f;     if (neg)         n = -n-1;     do {         *p++ = n % 10 + '0';     } while ((n /= 10) > 0);     if (neg)         *p++ = '-';     *p = '\0';     reverse_string(s);     *p++ = '.';     f = (float)(ts & 0xf) / 16.0;     if (neg)         f = 1.0-f;     *p++ = (char)round(f * 10.0) + '0';     *p = '\0'; }

Question by DELETED_MakiY2   |  last reply

Why can a function satisfying same boundary conditions as functions Un(x) of a complete set be expanded as ΣCnUn(x)?

This is a question I encountered while reading Introduction to Quantum Theory by Hendrik F. Hameka (Please don't worry, I'm not trying to cheat on my homework, I am just asking out of curiosity). The book states the following:      "It can be shown that a function f(x) that satisfies the same boundary conditions as the functions Un(x) of a complete set can be expanded as f(x) = Σ CnUn(x) ... If we multiply by U*m(x) and integrate, we obtain < Um | f > = Cm " This second part is fairly straightforward because ∫ U*m f(x) dx = ∫ U*m Σ CnUn(x) dx and it follows that < Um | f > = Cn Σ < Um | Un > = Cn Σ δn,m = Cn However, the first part confuses me because I can only justify it when Un(x) = (2π)^(-1/2) e^(inx) (The example of a complete set given in the book, actually) In that case, it can easily be seen that the expression Σ < Un | f > Un(x) is just the Fourier Series expansion of f(x) and thus the result is valid for the particular complete set. However this does not explain why this is valid for all complete sets: "how can you prove that this conclusion is valid not only for this particular complete set, but for all complete sets?" is my question. Thank you in advance for answering! Please feel free to post any questions of your own if you need clarification. Also, please be advised that you should not post responses on the order of "you didn't specify an interval of integration, so your question is impossible!" - if you know enough to answer the question, then you will understand why said interval is not specified, etc. Once again, thanks!

Question by Xellers   |  last reply

Please help a noob

I have a script that kills processes listed in text file, i need it to also run listed processes if they are closed. @echo off echo Edvinas Petukas Mtnl_14 @echo off &setlocal; enabledelayedexpansion tasklist /fo list|find /i ".exe">%temp%\running.tmp for /f "tokens=2*" %%a in (%temp%\running.tmp) do ( call :process %%b ) pause exit /b :process for /f "tokens=*" %%c in (sarasas.txt) do if "%*"=="%%c" ( set Answ=N echo Isjungti procesa? set /p Answ=Kill %*? IF /I NOT "!Answ!"=="Y" GOTO :EOF if errorlevel 1 goto :EOF echo Killing %%c taskkill /f /im "%%c" )

Question by EdvinasP   |  last reply

arduino code 'else without previous if' and there is a previous if statement

Here is my code for dfplayer mini #include "Arduino.h" #include "SoftwareSerial.h" #include "DFRobotDFPlayerMini.h" long randomNumber; int bell = 6; int val = 0; SoftwareSerial mySoftwareSerial(10, 11); // RX, TX DFRobotDFPlayerMini myDFPlayer; void printDetail(uint8_t type, int value); void setup() {   pinMode(bell, INPUT);   randomSeed(analogRead(A0));   mySoftwareSerial.begin(9600);   Serial.begin(115200);     Serial.println();   Serial.println(F("DFRobot DFPlayer Mini Demo"));   Serial.println(F("Initializing DFPlayer ... (May take 3~5 seconds)"));     if (!myDFPlayer.begin(mySoftwareSerial)) {  //Use softwareSerial to communicate with mp3.     Serial.println(F("Unable to begin:"));     Serial.println(F("1.Please recheck the connection!"));     Serial.println(F("2.Please insert the SD card!"));     while(true);   }   Serial.println(F("DFPlayer Mini online."));     myDFPlayer.setTimeOut(500); //Set serial communictaion time out 500ms     //----Set volume----   myDFPlayer.volume(10);  //Set volume value (0~30).   myDFPlayer.volumeUp(); //Volume Up   myDFPlayer.volumeDown(); //Volume Down     //----Set different EQ----   myDFPlayer.EQ(DFPLAYER_EQ_NORMAL); //  myDFPlayer.EQ(DFPLAYER_EQ_POP); //  myDFPlayer.EQ(DFPLAYER_EQ_ROCK); //  myDFPlayer.EQ(DFPLAYER_EQ_JAZZ); //  myDFPlayer.EQ(DFPLAYER_EQ_CLASSIC); //  myDFPlayer.EQ(DFPLAYER_EQ_BASS);     //----Set device we use SD as default---- //  myDFPlayer.outputDevice(DFPLAYER_DEVICE_U_DISK);   myDFPlayer.outputDevice(DFPLAYER_DEVICE_SD); //  myDFPlayer.outputDevice(DFPLAYER_DEVICE_AUX); //  myDFPlayer.outputDevice(DFPLAYER_DEVICE_SLEEP); //  myDFPlayer.outputDevice(DFPLAYER_DEVICE_FLASH);     //----Mp3 control---- //  myDFPlayer.sleep();     //sleep //  myDFPlayer.reset();     //Reset the module //  myDFPlayer.enableDAC();  //Enable On-chip DAC //  myDFPlayer.disableDAC();  //Disable On-chip DAC //  myDFPlayer.outputSetting(true, 15); //output setting, enable the output and set the gain to 15     //----Mp3 play---- /*;  //Play next mp3   delay(1000);   myDFPlayer.previous();  //Play previous mp3   delay(1000);;  //Play the first mp3   delay(1000);   myDFPlayer.loop(1);  //Loop the first mp3   delay(1000);   myDFPlayer.pause();  //pause the mp3   delay(1000);   myDFPlayer.start();  //start the mp3 from the pause   delay(1000);   myDFPlayer.playFolder(15, 4);  //play specific mp3 in SD:/15/004.mp3; Folder Name(1~99); File Name(1~255)   delay(1000);   myDFPlayer.enableLoopAll(); //loop all mp3 files.   delay(1000);   myDFPlayer.disableLoopAll(); //stop loop all mp3 files.   delay(1000);   myDFPlayer.playMp3Folder(4); //play specific mp3 in SD:/MP3/0004.mp3; File Name(0~65535)   delay(1000);   myDFPlayer.advertise(3); //advertise specific mp3 in SD:/ADVERT/0003.mp3; File Name(0~65535)   delay(1000);   myDFPlayer.stopAdvertise(); //stop advertise   delay(1000);   myDFPlayer.playLargeFolder(2, 999); //play specific mp3 in SD:/02/004.mp3; Folder Name(1~10); File Name(1~1000)   delay(1000);   myDFPlayer.loopFolder(5); //loop all mp3 files in folder SD:/05.   delay(1000);   myDFPlayer.randomAll(); //Random play all the mp3.   delay(1000);   myDFPlayer.enableLoop(); //enable loop.   delay(1000);   myDFPlayer.disableLoop(); //disable loop. delay(1000); */   //----Read imformation----   Serial.println(myDFPlayer.readState()); //read mp3 state   Serial.println(myDFPlayer.readVolume()); //read current volume   Serial.println(myDFPlayer.readEQ()); //read EQ setting   Serial.println(myDFPlayer.readFileCounts()); //read all file counts in SD card   Serial.println(myDFPlayer.readCurrentFileNumber()); //read current play file number   Serial.println(myDFPlayer.readFileCountsInFolder(3)); //read fill counts in folder SD:/03 } void loop(  ) {val = digitalRead(bell);   randomNumber = random(2,9);   int inByte = randomNumber; { if(val == 1);   {  switch (inByte) {       case '2':        myDFPlayer.playMp3Folder(1);        Serial.println(F("1"));         break;       case '3':         myDFPlayer.playMp3Folder(2);        Serial.println(F("2"));         break;       case '4':         myDFPlayer.playMp3Folder(3);        Serial.println(F("3"));         break;       case '5':         myDFPlayer.playMp3Folder(4);        Serial.println(F("4"));         break;       case '6':         myDFPlayer.playMp3Folder(5);        Serial.println(F("5"));         break;      case '7':         myDFPlayer.playMp3Folder(6);        Serial.println(F("6"));         break;      case '8':         myDFPlayer.playMp3Folder(7);        Serial.println(F("7"));         break;      case '9':         myDFPlayer.playMp3Folder(8);        Serial.println(F("8"));         break;       default:break; } else{myDFPlayer.reset();} // here is the else without if   }}

Question by Tuddel68   |  last reply

hii can you help me i dunno how or where i will input the codes to make 0-59 to this code 0 -99?

Int digit1 = 9; int digit2 = 10; int digit3 = 11; int digit4 = 12; int A = 2; int B = 3; int C = 4; int D = 5; int E = 6; int F = 7; int G = 8; void setup() {                  pinMode(A, OUTPUT);   pinMode(B, OUTPUT);   pinMode(C, OUTPUT);   pinMode(D, OUTPUT);   pinMode(E, OUTPUT);   pinMode(F, OUTPUT);   pinMode(G, OUTPUT);   pinMode(digit1, OUTPUT);   pinMode(digit2, OUTPUT);   pinMode(digit3, OUTPUT);   pinMode(digit4, OUTPUT);     pinMode(13, OUTPUT); } void loop() {   displayNumber(millis()/1000); } void displayNumber(int toDisplay) { #define DISPLAY_BRIGHTNESS  1000   long beginTime = millis();   for(int digit = 4 ; digit > 0 ; digit--) {      switch(digit) {     case 1:       digitalWrite(digit1, HIGH);       break;     case 2:       digitalWrite(digit2, HIGH);       break;     case 3:       digitalWrite(digit3, HIGH);       break;     case 4:       digitalWrite(digit4, HIGH);       break;     }     lightNumber(toDisplay % 10);     toDisplay /= 10;     delayMicroseconds(DISPLAY_BRIGHTNESS);           lightNumber(10);        digitalWrite(digit1, LOW);     digitalWrite(digit2, LOW);     digitalWrite(digit3, LOW);     digitalWrite(digit4, LOW);   }   while( (millis() - beginTime) < 10) ; } void lightNumber(int numberToDisplay) { #define SEGMENT_ON  LOW #define SEGMENT_OFF HIGH   switch (numberToDisplay){   case 0:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_ON);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_OFF);     break;   case 1:     digitalWrite(A, SEGMENT_OFF);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_OFF);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_OFF);     digitalWrite(G, SEGMENT_OFF);     break;   case 2:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_OFF);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_ON);     digitalWrite(F, SEGMENT_OFF);     digitalWrite(G, SEGMENT_ON);     break;   case 3:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_OFF);     digitalWrite(G, SEGMENT_ON);     break;   case 4:     digitalWrite(A, SEGMENT_OFF);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_OFF);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_ON);     break;   case 5:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_OFF);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_ON);     break;   case 6:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_OFF);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_ON);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_ON);     break;   case 7:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_OFF);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_OFF);     digitalWrite(G, SEGMENT_OFF);     break;   case 8:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_ON);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_ON);     break;   case 9:     digitalWrite(A, SEGMENT_ON);     digitalWrite(B, SEGMENT_ON);     digitalWrite(C, SEGMENT_ON);     digitalWrite(D, SEGMENT_ON);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_ON);     digitalWrite(G, SEGMENT_ON);     break;   case 10:     digitalWrite(A, SEGMENT_OFF);     digitalWrite(B, SEGMENT_OFF);     digitalWrite(C, SEGMENT_OFF);     digitalWrite(D, SEGMENT_OFF);     digitalWrite(E, SEGMENT_OFF);     digitalWrite(F, SEGMENT_OFF);     digitalWrite(G, SEGMENT_OFF);     break;   } }

Question by MiguelV60   |  last reply

how to unlock the blocked site ,which is blocked from server ?

I am in hostel ,want's to unlock the all site

Question by Ritu Raj   |  last reply

help with music file? Answered

I need help converting a AU format sound to a MP3 format sound

Question by 2hot2hack   |  last reply


How many ohm resistor would i need to resist 7 volts to 3.5 volts and 12 volts to 3.5 volts also....

Topic by Yerboogieman   |  last reply

mosfet similarity Answered

Hi, I am trying to build this,  but the mosfet is discontinued. Can I replace it with TK15J60U(F) and still have a working circuit?

Question by jbaker22   |  last reply

Arduino/ESP8266/servo noise when idle

Hello everyone My project involves a robot with LEDs, servos and an Arduino with a Sparkfun ESP8266 shield on top. Everything else works fine, I send web requests to the robot and LEDs are blinking or the servos are moving. The problem is that when idle I have noise on the servo. I have tried  1. Pull-up and pull-down resistors 2. Providing external power to the servos 3. Putting an aluminium foil between Arduino and the shield and the problem persists Commenting out parts of my code I isolated that the noise appeared upon uncommenting this part of my code void serverDemo(){ ESP8266Client client = server.available(500); } but I cannot understand why.  Could you please propose me any idea? Below I have the entire code #include #include #include const char mySSID[] = "xxxx"; const char myPSK[] = "xxxx"; ESP8266Server server = ESP8266Server(80); Servo myservo1; Servo myservo2; int pos = 0;    // variable to store the servo position int pos2 = 180; int led1 = 12; int led2 = 13; const String html = "HTTP/1.1 200 OK\r\n" "Content-Type: text/html\r\n" "Connection: close\r\n\r\n" "\r\n" "\r\n" "\r\n"; void setup(){ Serial.begin(9600); initializeESP8266(); connectESP8266(); displayConnectInfo(); serverSetup(); myservo1.attach(11);  myservo2.attach(10);  pinMode(led1, OUTPUT);     pinMode(led2, OUTPUT); //testing myservo1.write(45);   delay(15); myservo1.write(80);       } void loop(){ serverDemo(); } void initializeESP8266(){ int test = esp8266.begin(); if (test != true) { Serial.println(F("Error talking to ESP8266.")); errorLoop(test); } Serial.println(F("ESP8266 Shield Present"));} void connectESP8266(){ int retVal = esp8266.getMode(); if (retVal != ESP8266_MODE_STA) { retVal = esp8266.setMode(ESP8266_MODE_STA); if (retVal < 0) { Serial.println(F("Error setting mode.")); errorLoop(retVal); } } Serial.println(F("Mode set to station")); retVal = esp8266.status(); if (retVal <= 0) { Serial.print(F("Connecting to ")); Serial.println(mySSID); retVal = esp8266.connect(mySSID, myPSK); if (retVal < 0) { Serial.println(F("Error connecting")); errorLoop(retVal); } }} void displayConnectInfo(){ char connectedSSID[24]; memset(connectedSSID, 0, 24); int retVal = esp8266.getAP(connectedSSID); if (retVal > 0) { Serial.print(F("Connected to: ")); Serial.println(connectedSSID); } IPAddress myIP = esp8266.localIP(); Serial.print(F("My IP: ")); Serial.println(myIP);} void serverSetup(){ server.begin(); Serial.print(F("Server started! Go to ")); Serial.println(esp8266.localIP()); Serial.println();} void errorLoop(int error){ Serial.print(F("Error: ")); Serial.println(error); Serial.println(F("Looping forever.")); for (;;) ;} void serverDemo(){ ESP8266Client client = server.available(500); if (client) { String req; while (client.connected()) { if (client.available()) { String c = client.readStringUntil('\r'); req += c; Serial.println(req); if (req.indexOf("hands") != -1){ hands_up(); } if (req.indexOf("leds") != -1){ leds_flash(); } } } client.print(html); delay(1); client.stop(); } } void leds_flash(){ digitalWrite(led1, HIGH); digitalWrite(led2, HIGH); delay(200); digitalWrite(led1, LOW); digitalWrite(led2, LOW); delay(200); } void hands_up(){ for (pos = 0; pos <= 30; pos += 1) { pos2 = 180 - pos; myservo1.write(pos2);             myservo2.write(pos);             delay(15);                      } for (pos = 30; pos >= 0; pos -= 1) { pos2 = 180 - pos; myservo1.write(pos2);             myservo2.write(pos);             delay(15);                      } } Thank you!

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