When you’re making a microcontroller circuit that drives a high current load like a motor or an incandescent light, it’s not uncommon to make a mistake and create a circuit that draws too much electrical energy on startup and causes the microcontroller to reset itself constantly. To debug this, it helps to put a routine in your startup() function so you can see when the microcontroller has started up. For example, I often blink an LED three times in the startup. If the LED blinks three times then stops, I know the microcontroller has successfully run the startup and gone into its main loop. If it blinks constantly, I know the microcontroller is continually resetting, so there’s a problem.<\/p>\n
Hans Steiner recently showed me his trick for checking for the startup routine on the Arduino: he writes to the microcontroller’s EEPROM, or permanent memory, and reads back the result. Every time the Arduino resets, it’ll increment the EEPROM value. Since this value is stored even when the Arduino is not powered, you’re going to get a new number each time it’s run.<\/p>\n
Thanks to Hans for the code.<\/p>\n
<\/p>\n
Technorati Tags: pcomp<\/a>, physical computing<\/a><\/p>\n Since this value is stored even when the Arduino is not powered, you’re going to get a new number each time it’s run.Thanks to Hans for the code.\/* EEPROM reset checker By Hans Steiner Reads a value from the EEPROM on startup, prints it out, and increments the value then stores it back in EEPROM…. Created 25 Oct. 2007*\/ #include <EEPROM.h>int potPin = 5; \/\/ select the input pin for the potentiometerint motorPin = 9; \/\/ select the pin for the LEDint value = 0; \/\/ variable to store the value coming from the sensorint resetCountByte = 36;void setup() { \/\/ open the serial port Serial.begin(9600); \/\/ read the last value stored in the EEPROM: value = EEPROM.read(resetCountByte); \/\/ send it out the serial port: Serial.println(value); \/\/ increment it and write it back to the EEOPROM: EEPROM.write(resetCountByte, value + 1); pinMode(motorPin, OUTPUT); \/\/ declare the motor as an OUTPUT pinMode(13, OUTPUT); \/\/ declare the LED pin as an output digitalWrite(13,HIGH); \/\/ turn on the LED}void loop() { \/\/ you can do anything you want to here.}<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9,24],"tags":[],"class_list":["post-125","post","type-post","status-publish","format-standard","hentry","category-arduinowiring","category-circuits"],"_links":{"self":[{"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/posts\/125","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/comments?post=125"}],"version-history":[{"count":0,"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/posts\/125\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/media?parent=125"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/categories?post=125"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tigoe.com\/pcomp\/code\/wp-json\/wp\/v2\/tags?post=125"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\n<\/p>\n\/*\n EEPROM reset checker\n By Hans Steiner\n\n Reads a value from the EEPROM on startup, prints it out,\n and increments the value then stores it back in EEPROM.\n This is a handy way to check for resetting programs, because the \n EEPROM value will only be incremented and stored in memory on startup.\n\n Created 25 Oct. 2007\n*\/\n \n#include <EEPROM.h>\n\nint potPin = 5; \/\/ select the input pin for the potentiometer\nint motorPin = 9; \/\/ select the pin for the LED\nint value = 0; \/\/ variable to store the value coming from the sensor\nint resetCountByte = 36;\n\nvoid setup() {\n \/\/ open the serial port\n Serial.begin(9600);\n \/\/ read the last value stored in the EEPROM:\n value = EEPROM.read(resetCountByte);\n \/\/ send it out the serial port:\n Serial.println(value);\n \/\/ increment it and write it back to the EEOPROM:\n EEPROM.write(resetCountByte, value + 1);\n\n pinMode(motorPin, OUTPUT); \/\/ declare the motor as an OUTPUT\n pinMode(13, OUTPUT); \/\/ declare the LED pin as an output\n digitalWrite(13,HIGH); \/\/ turn on the LED\n}\n\nvoid loop() {\n \/\/ you can do anything you want to here.\n}\n<\/pre>\n","protected":false},"excerpt":{"rendered":"