Minecraft Forums

Not to be lazy here but seriously, there are tonnes of these tutorials. Go find a god one, set it up, and come back here.

Download the UE api from here and my UE developing kit here. Unzip them both, then put them in your mcp/src/minecraft folder.

Ok, so let's look at my code for an example.

package spaceage.common.tile;

import cpw.mods.fml.relauncher.Side;
import cpw.mods.fml.relauncher.SideOnly;
import spaceage.common.SpaceAgeCore;
import uedevkit.tile.TileElectricBase;

public class TileSolarPanel extends TileElectricBase {

    public TileSolarPanel() {
    }

    @Override
    public void readFromNBT(NBTTagCompound nbt) {
        super.readFromNBT(nbt);
    }

   @Override
   public void writeToNBT(NBTTagCompound nbt) {
      super.writeToNBT(nbt);
   }

   @Override
   public void updateEntity() {
      super.updateEntity();

      this.produce();

      if (!this.worldObj.isRemote) {
         if (this.worldObj.canBlockSeeTheSky(xCoord, yCoord + 1, zCoord) && !this.worldObj.provider.hasNoSky) {
            if (this.worldObj.isDaytime()) {
               if (!(this.worldObj.isThundering() || this.worldObj.isRaining())) {
                  if(!this.energy.isFull()) {
                     Long produced = Long.valueOf(SpaceAgeCore.SOLAR_ENERGY);
                     this.produceEnergy(produced);
                   }
               }
            }
         }
      }
   }
}

There is a method called updateEntity that is called whenever there is a tick. The 'super.updateEntity' is required first so that the class that I am extending (in this case TileElectric)'s updateEntity is called. After that, there is the 'this.produce()'. That is in a referenced class and basically allows other machines to pull power from the internal energy storage of this generator. Then there is a test to see whether the conditions that allow power to be generated is met. If it is true, then a certain amount of energy is produced. This is basically everything you need for a generator. For a coal based generator, it would require inventory use and a different test.