THE FRANKENGRIDDLE PROJECT It started out innocently enough with a griddle & burner from a 1970's Wolf stove... The griddle area is about 11" x
25" with a gutter and drain on one side. The slab is 3/4" thick and the
griddle weighs about 48 lbs. It looks like it should be able to cook a
fair bit of bacon at once. I mounted it on top of an old stainless steel food service cart with nice heavy duty castors so it's mobile. There's room inside for a propane
bottle. The burner control knob is on the front and there's a removable drip
tray on the left. Mmmmm... It makes breakfast! I guess the
project wouldn't have been too silly if I had just left it at
that.
But wait, there's more.... I was poking around through my "junk box" and found some other stuff that looked interesting. A type K temperature probe, a small stepper motor from an old printer, a stepper driver circuit from an old discarded project, a 16 x 2 LCD display, and a microcontroller board I designed and built for another project. The controller board contains a 16F887 controller, a DS1302 real time clock, a 24LC128 EEPROM, 5 volt regulator, and some MOSFET output drivers. So I stuck that pile of hardware together with a little solder, connected the stepper motor to the gas valve, hacked up a few lines of code for the processor and presto... A temperature controlled griddle with a digital display! The processor reads a type K temperature probe that's embedded in a hole in the side of the griddle. The stepper motor has a 6:1 gear reduction to the gas valve shaft and with the half step driver that gives a resolution of 0.15 degrees of valve rotation. The temperature is user adjustable from 275° to 450° (F) and the processor uses a PID routine that gives very good control of the temperature. When first powered up the LCD shows a friendly greeting message and then it displays the current griddle temperature, the user adjustable setpoint, the current time, and the current gas valve position. The menu button allows access to select auto or manual control mode, time set mode, backlight brightness, and adjustment of several variables used in the PID calculations. It was kind of a crazy project but it works very well and it makes excellent woven bacon! And Frankengriddle makes English Muffins too! ---------------------------------------- Frankengriddle is still a work in progress and hardware & firmware updates are being made regularly. ---------------------------------- Current Frankengriddle features include:
----------------------------------------------- Materials you will need to build this project: One griddle and burner from an old Wolf stove. (or substitute whatever you have laying around) One stainless steel "food service cart" on wheels. (or substitute whatever you have laying around) One small stepper motor from an old printer. (or substitute whatever you have laying around) L297/ L298 stepper driver chipset. (or substitute whatever you have laying around) One 16 x 2 LCD display. (or substitute whatever you have laying around) One home built controller board. Mine has a 16F887 processor, real time clock, and plenty of EEPROM. (substitute whatever you have laying around) Assorted bits of angle iron, sheet metal, pipe, screws, switches, wire, solder, & heat shrink tubing. (Substitute whatever you have laying around) Plenty of bacon for testing. (no substitutions) ---------------------------------------------- Tools you will need to build this project: MIG welder Pipe wrench Soldering iron Hammer Tweezers Reflow oven Safety glasses A well stocked kegerator ---- Have fun kids & don't hurt yourself! |