Heat stick handbook

Heat sticks have been used in the home brewing community for years. Correctly constructed they are safe (but pay serious caution whenever mixing electricity and water).

What makes the heat stick here different is the use of a JeeNode and SSR (along with a 12 AWG power cord, a male and a female electrical plug) to create a separate device that acts as a remote "switch" to turn the temperature actuator (heat stick) on and off according to readings gathered from the temperature sensor (thermometer).

Basically this means that a special cord is used that allows the remote (wireless) operation (turning on and off) of any device that plug into an electrical outlet. The primary application of this is to 1500 watt heating elements that heat liquids for industrial and culinary processes like home cooking or a homebrew cancer drug.


the main modification is that there's no ground nut hole, #6 ground bolt, ground nut, washer. instead you leave some exposed ground (green) wire hanging outside the fitting as in the second link above

Heat stick Bill of Materials (BOM)

    example part

  • Camco 1500W 120V Screen Element 02143
    example part
    example part

  • 12 gauge, 3-wire Rubber Electrical Cord
    Available at most hardware stores

  • Heavy Duty 20 amp Armored 3-Prong Plug
    Available at most hardware stores and online

  • 12" Long X 1 1/2" I. D. Chrome Plated, Brass Drain Pipe
    exampe part

  • 6" Long X 1 1/2" I. D. Plastic Drain Pipe Extension Tube with Compression Fitting
    example part
  • 3/4" PVC Coupler
  • 1" PVC End Cap
  • J-B Weld

Relay cord handbook

A 12 AWG SSR cord is made by attaching a female electrical plug and a male electrical plug to 12 AWG cord to make a complete electrical cord and then cutting into the middle of the cord, cutting the black wire (the other two are white and green) and attaching it to an SSR (solid state relay).

When you attach a JeeNode (with the 22 guage wire) to one side and attach the ends of the exposed and cut black cord from the 12 AWG cord on the other side of the solid state relay, it allows the JeeNode to turn whatever you plug into the cord on and off, according to however the JeeNode is programmed (which could be to listen to instructions from the JeeLink, and hence your home computer).

The device being turned on and off could be any 120 volt device. It could be a heat stick but it could also be a corded drill for example.

SSR cord Bill of Materials (BOM)

Step by step procedure

0) Cord length: it's a good idea to have one long cord as your first cord, since it can be used in many situations. Most other cords should be a lot shorter than your "extension" SSR cord.

1) Use your utility knife (you have a utility knife, don't you?) to cut the rubber sheath of your 12 AWG (American Wire Gauge) 3 wire cord so that the three wires (green, white and black) are exposed. Cut the sheath into thirds with three different four inch cuts. Cut off the resulting flaps so your three wires are exposed. There may be some confetti-like paper insulation material in there too so be ready to throw that out.

2) Cut an inch worth of insulation off each of the black, green and white wires. Throw this insulation away.

3) Repeat steps 1 and 2 on the other side of your cord.

4) Give each of the exposed copper wires a twist so they're more solid and less frayed. This will help when attaching them to the male and female plugs.

5) Use your utility knife (or a proper screwdriver, which is safer) to open the male plug.

6) Make solid contacts. Don't let any of the copper wire strands somehow bridge and touch another wire. GREEN IS GROUND. ATTACH IT TO THE GROUND PLUG.

7) Secure everything back on tight.

8) Repeat for female electrical plug.

9) Somewhere along the cord (the middle is fine) make a cut into the black rubber sheath without cutting any of the inner wires. If the cord is short you can judge from the two ends where the black wire might be. Either way, find it once the black sheath has been cut. Only cut the black sheath four inches, enough to snip the black wire in two, remove an inch of rubber insulation from sides of the cut, and attach it to the SSR (Solid State Relay).

10) Twist the ends so they're not frayed. Attach to the AC side of the SSR (Solid State Relay).

11) Expose all ends of two 5 inch strands of 22 AWG wire. Secure them on the DC side of the SSR.

12) Flash the jeenode with the following code.

SSR Receiver code

13) It's time to hook up the jeenode.

To connect the jeenode to the SSR you should locate the SPI/ISP region on the back of your jeenode (v6). Connect one of your 22 gauge wires from the 3-25 DC volt side of your SSR to +3v and the other to B1. Make sure not to have a heat stick plugged in and out of water when testing (if it's in open air while plugged in they'll glow red hot and it'll be very dangerous and it will break or worse).

TODO: Image showing connections on board

You can test this SSR cord on a lamp or a drill.

Step 14) Hook up a power source to the jeenode.

TODO: See section on hooking up power.

Step 15) Plug in the jeelink

TODO: See section on hooking up jeelink

Step 16) In the code above there is a NID (node ID) and GID (group ID). Refer to the jeenode documentation on these. http://jeelabs.org