arduino resistance measurement?

-

hi again. have photocell , wondering if possible use arduino measure resistance cell.


note: photocell creates resistance depending on light, 1k ohm in dark , 10k ohms in bright light.

connect 1 end of photocell +5v , other end 1k resistor. connect other end of resistor ground. connect wire resistor/photocell junction analog pin.

call analogread read value. value go or down depending on how light hitting photocell.

the photocell/resistor combination forms voltage divider, changes amount of current flowing, depending on changing resistance of photocell. measuring voltage dropped photocell gives measure of resistance of photocell.


Arduino Forum > Forum 2005-2010 (read only) > Software > Syntax & Programs > arduino resistance measurement?


arduino

Comments

Post a Comment

Popular posts from this blog

CAN'T INSTALL MAMBELFISH 1.5 FROM DIRECTORY - Joomla! Forum - community, help and support

-
hi, i want install mambelfish 1.5 component in joomla! 1.0.4 stable [ sundial ] site, reason following error: failed create directory "/home/virtual/site13/fst/var/www/html/components/com_mambelfish/" i new joomla! , still not familiar it. great if build multilingual sites using joomla!. just clarify... media/ writeable administrator/components/ writeable components/ writeable images/stories/ writeable how install component? use  upload package file or use  install directory ? Board index Joomla! Older Version Support Joomla! 1.0 Extensions - 1.0.x Components
Read more

error: expected initializer before 'void'

-
whenever try compile code following error : 'error: expected initializer before 'void'' code: [select] #include <afmotor.h> af_dcmotor motor1(1, motor12_64khz); // create motor #1, 64khz pwm af_dcmotor motor2(2, motor12_64khz); // motor #2 void setup() {  serial.begin(9600);           // set serial library @ 9600 bps  serial.println("motor test!"); } void loop() { go(); backup(); halt(); }   void go() {  serial.println("all motors ahead - fast");    motor1.run(forward);  motor2.run(forward);  motor1.setspeed(255);  motor2.setspeed(255);  return; } void backup() {  serial.println("all motors backward - fast");  motor1.run(backward);  motor2.run(backward);  motor1.setspeed(255);  motor2.setspeed(255);  return; } void halt() {  uint8_t i;  for (i=255; i!=0; i--) ...
Read more

CPU load monitoring using GPIO and leds - Raspberry Pi Forums

-
Image
hello ! wrote today article on blog cpu load monitoring (using gpio , leds) on raspberry's. simple (written in little shell script), think can useful (for people want learn leds stuff on r. pi) there 5 leds turning on , off regarding cpu load: - cpu < 20%: 1 led - cpu < 40%: 2 leds - cpu < 60%: 3 leds - cpu < 80%: 4 leds - cpu < 90%: 5/5 leds - cpu >= 90%: 5 leds flashing here article: written in french, can watch youtube video , download code @ bottom of article. http://www.chteuchteu.com/2012/10/26/ra ... e-au-gpio/ if find errors in code, can post comment on article. ! up code enhancements ? raspberrypi
Read more