Decoupling a 0.5V drop every 3ms

-

hello,

i've got following circuit:

arduino micro
2x ht16k33 led drivers (on adafruit breakout, connected i2c)
4x analog sensors connected analog inputs 100uf , 1uf in parallel in front of them (as suggested in datasheet of sensors)

everything working supposed to, since connecting led drivers there lot of noise on reading of analog inputs.

i connected scope , noticed it's 5v power supply coming arduino has regular noise on (see attachment).
it starts 0.5v drop , in middle of cycle again noticable drop of 0.1v?

maybe should mention current 100uf / 1uf combination used 1 time in front of first sensor, power , grounds parallel wired there on following 3 sensors.


i suppose solvable using right capacitors in circuit?

is there formula calculate values capacitors, based on noise see on scope?

looks don't have star-ground setup.  how current leds take?


Arduino Forum > Using Arduino > General Electronics > Decoupling a 0.5V drop every 3ms


arduino

Comments

Post a Comment

Popular posts from this blog

DHT11 Time out error using v0.4.1library

-
Image
i'm struggling dht11 sensor work on arduino. code compiles without problems in serial monitor output keep on getting " read sensor: time out error" i've tried multiple libraries, adafruit etc still none of them worked. set serial monitor same speed (115200) didn't fix problem.  i'm using:  mega2560  dht11 temp+hum sensor windows10 x64 arduino 1.6.9 library dht11.h v0.4.1 source:  http://playground.arduino.cc/main/dht11lib wiring : blue = gnd yellow = 2 red = 5v (also see picture)  my code:    code: [select] #include <dht11.h> // //   file:  dht11_test1.pde // purpose: dht11 library test sketch arduino // //celsius fahrenheit conversion double fahrenheit(double celsius) {   return 1.8 * celsius + 32; } // fast integer version rounding //int celcius2fahrenheit(int celcius) //{ //  return (celsius * 18 + 5)/10 + 32; //} //celsius kelvin conversion double kelvin(double celsius) {   return ...
Read more

Sketch upload fails with Java error (___REMOVE___/bin/avrdude)!

-
hi, i'm getting same error despite have tried 2 boards , done arduino reinstall in windows 7 machine! while trying update "bareminimum" in verbose mode: code: [select] arduino: 1.8.0 (windows 7), board: "arduino/genuino uno" sketch uses 450 bytes (1%) of program storage space. maximum 32256 bytes. global variables use 9 bytes (0%) of dynamic memory, leaving 2039 bytes local variables. maximum 2048 bytes. ___remove___/bin/avrdude -c___remove___/etc/avrdude.conf -v -patmega328p -carduino -pcom8 -b115200 -d -uflash:w:c:\users\rui\appdata\local\temp\arduino_build_445303/bareminimum.ino.hex:i java.io.ioexception: cannot run program "___remove___/bin/avrdude": createprocess error=2, system cannot find file specified  at java.lang.processbuilder.start(processbuilder.java:1048)  at processing.app.helpers.processutils.exec(processutils.java:26)  at cc.arduino.packages.uploader.executeuploadcommand(uploader.java:129)  at cc.arduino.p...
Read more

Arduino Uno + KTY81/210 temperature sensor

-
Image
hi, sorry, new , unsure lot of things, need clarification. haven't found information explains how , why things work, "do this, that" i following guide ( arduino-thermistor-temperature-sensor-tutorial ) connect thermistor arduino uno. here temperature sensor information: temp. sensor 2000r +-1% to92 part.no.:   kty81-210 name:   temp. sensor 2000r +-1% to92 description:   2.5mm, 1980...2020ohm, -55...+150°c and here sensor's data-sheet: sensor data-sheet i have connected same way in guide. works , values being serial printed. what don't understand: 1. thermistor's , resistor's ohm value should equal, correct? in case 2000 ohm? 2. thermistor has ptc, i'm guessing have invert math or use ntc thermistor instead correct values? (currently resistance goes temperature goes down) 3. understand code uses steinhart-hart math logic convert resistor value temperature value, need a, b , c coefficients of thermis...
Read more