Arduino 4-Digit 7-Segment Display
by jreilly on Apr.13, 2010, under Arduino, Electronics
Source code:
long n = 0; int x = 100; int del = 1; void setup(){ // clearLEDs(); // testLEDs(); pinMode(13, OUTPUT); pinMode(12, OUTPUT); pinMode(11, OUTPUT); pinMode(10, OUTPUT); pinMode(9, OUTPUT); pinMode(8, OUTPUT); pinMode(7, OUTPUT); pinMode(6, OUTPUT); pinMode(5, OUTPUT); pinMode(4, OUTPUT); pinMode(3, OUTPUT); pinMode(2, OUTPUT); pinMode(1, OUTPUT); } void loop(){ clearLEDs(); pickDigit(1); pickNumber((n/x/1000)%10); delayMicroseconds(del); clearLEDs(); pickDigit(2); pickNumber((n/x/100)%10); delayMicroseconds(del); clearLEDs(); pickDigit(3); pickNumber((n/x/10)%10); delayMicroseconds(del); clearLEDs(); pickDigit(4); pickNumber(n/x % 10); delayMicroseconds(del); if(n/x > 9999){ n = 0; delay(5000); } else n++; } void pickDigit(int x){ digitalWrite(13, LOW); // dig 1 digitalWrite(12, LOW); // dig 2 digitalWrite( 9, LOW); // dig 3 digitalWrite( 8, LOW); // dig 4 switch(x){ case 1: digitalWrite(13, HIGH); break; case 2: digitalWrite(12, HIGH); break; case 3: digitalWrite(9, HIGH); break; case 4: digitalWrite(8, HIGH); break; } } void pickNumber(int x){ switch(x){ case 1: one(); break; case 2: two(); break; case 3: three(); break; case 4: four(); break; case 5: five(); break; case 6: six(); break; case 7: seven(); break; case 8: eight(); break; case 9: nine(); break; default: zero(); break; } } void clearLEDs(){ //digitalWrite(13, HIGH); // digitalWrite(12, HIGH); //digitalWrite(9, HIGH); // digitalWrite(8, HIGH); digitalWrite( 5, HIGH); // A digitalWrite( 7, HIGH); // B digitalWrite( 4, HIGH); // C digitalWrite(11, HIGH); // D digitalWrite(10, HIGH); // E digitalWrite( 3, HIGH); // F digitalWrite( 6, HIGH); // G } void one(){ digitalWrite( 5, HIGH); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, HIGH); // D digitalWrite(10, HIGH); // E digitalWrite( 3, HIGH); // F digitalWrite( 6, HIGH); // G } void two(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, HIGH); // C digitalWrite(11, LOW); // D digitalWrite(10, LOW); // E digitalWrite( 3, HIGH); // F digitalWrite( 6, LOW); // G } void three(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, HIGH); // E digitalWrite( 3, HIGH); // F digitalWrite( 6, LOW); // G } void four(){ digitalWrite( 5, HIGH); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, HIGH); // D digitalWrite(10, HIGH); // E digitalWrite( 3, LOW); // F digitalWrite( 6, LOW); // G } void five(){ digitalWrite( 5, LOW); // A digitalWrite( 7, HIGH); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, HIGH); // E digitalWrite( 3, LOW); // F digitalWrite( 6, LOW); // G } void six(){ digitalWrite( 5, LOW); // A digitalWrite( 7, HIGH); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, LOW); // E digitalWrite( 3, LOW); // F digitalWrite( 6, LOW); // G } void seven(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, HIGH); // D digitalWrite(10, HIGH); // E digitalWrite( 3, HIGH); // F digitalWrite( 6, HIGH); // G } void eight(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, LOW); // E digitalWrite( 3, LOW); // F digitalWrite( 6, LOW); // G } void nine(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, HIGH); // E digitalWrite( 3, LOW); // F digitalWrite( 6, LOW); // G } void zero(){ digitalWrite( 5, LOW); // A digitalWrite( 7, LOW); // B digitalWrite( 4, LOW); // C digitalWrite(11, LOW); // D digitalWrite(10, LOW); // E digitalWrite( 3, LOW); // F digitalWrite( 6, HIGH); // G }
You probably don’t understand Unicode
by jreilly on Dec.09, 2009, under Programming
Joel Spolsky fixes that:
Die Hard 2 in HD is hilarious
by jreilly on Dec.07, 2009, under Movies
Not only does HD make new movies and shows better, it makes older movies from the pre-HD era even more awesome. Case in point, one of my favorites: Die Hard 2. Director Renny Harlin probably never expected that this scene would be seen in such clarity. These images are from a 30 second sequence where a terrorist on top of some scaffolding falls and is crushed by said scaffold. A tense and brutal scene when viewed in standard definition turns into something else when viewed in HD: (continue reading…)
SQL “Contains All” Query
by admin on Dec.01, 2009, under SQL
Problem: You want to return a set of employees that have all of the necessary skills to perform a particular task. A generalization of this would be something like, “return the objects in set A which contain all of the properties of a chosen item of set B”.
You have a table of Employees and a table of Tasks. Both make use of a common Skills table. The Employee table is linked to the Skills table by the table EmployeeHasSkill. The Task table is linked to the Skills table by TaskRequiresSkill. (continue reading…)
