Maple Controller

[Toblerone]

After last year's success with the homemade float valve and rigged-up calculator-as-pump-counter, I decided to do it up right. I am building a microcontroller-based evaporator controller unit.

It has a 16F88 microcontroler, a 4x20 back-lit LCD, 2 Temperature probes, a sap-level sensor, a relay-controlled 12V (cigarette) output jack (for a 12V sap pump), a timer, and an alarm beeper. It runs on a 12V cigarette plug so I can use one of those battery boosters for power. I intend to have it run these functions:

Sap before it reaches the pan
* Monitor sap head/preheater (for me, it's the same tank) tank level
* Turn on the sap pump when level is low, turn off the pump when high
* Sound an alarm if pump fails to fill tank after 30 seconds (no sap in feed tank)
* Sound and alarm if level fails to drop in 10 minutes (something wrong with evap. float)
* Calibrate sensor so that it pumps to 1 or 2 gallons at a time. Controller will keep track of how many gallons pumped, the time between pumps, and compute the per-pump and average gallons per hour processed. And it will keep a season total of gallons pumped so far.
* Monitor the time we are actively boiling, and total for the season

For Sap/Syrup in pan
* Monitor temperature near syrup outlet
* Sound an alarm if temperature reaches preset draw-off point (for manual valve opening)
* Someday attach an auto-drawoff valve.
* Sound an alarm if temperature gets too high (burning)
* Sound an alarm if temperature gets too low (low level, probe uncovered)

Maybe these functions:
* Monitor temperature of incoming sap
* Display ambient/room temperature
* Monitor temperature of preheated sap, if I ever build one!
* Monitor/display stack temperature

If you had such a system, what would you make it do?

[maple flats]

Can't help, I prefer hands on. I try to run constant draw, I walk around the evaporator constantly, I check the head tank level often, I check sap in flow often. I do not trust some things to automation where a little glitch could ruin a pan and lots of syrup.

[Toblerone]

I am very hands on too. But sometimes too many hands on can get out of hand. I used to adjust sap level by turning a valve up and down. Now I let a float valve handle that. I used to take a pail and fill the small preheater tank (over a propane burner) one pail at a time by hand. Now I have a float switch pump in sap when needed. I used to have to spend a long time finishing because I drew off too early. Now I will be able to drawoff closer to syrup. I used to do all of this often while giving a tour as well.

Also, I often have to leave the evaporator in the hands of volunteers as well. Some are more competent than others, so I want to have some automatic warnings built into the system. (Next I should have it call my cell when an alarm goes off!)

But, I am not trying to automate the process any more than necessary. I just want something to take over mundane liquid level tasks, save some basic statistics, and warn me when something should probably be done. I will likely have already done it, but it will be nice to know if I really am missing something. I once scorched a small part of the pan while I was futzing with a tarp during high winds. Hopefully the alarms will not let a small distraction turn into a giant one.

[Haynes Forest Products]

I regards to what I would want it to do......Marry Me:o Toblerone Have a friend that has the farm streached all over the place and when people drive into the saw mill 1/2 mile away a sensor at the entrance rings her cell phone.

I need one of those alarms that they put in the cab of Trains that every 2 min it sounds a buzzer and if you dont respond it starts applying the brakes:) Instead of the dead man switch we could call it the Burning pan switch:emb:

[maplemaple2020]

i never knew that pic 16f683 chip or what ever its called can do so much amazing keep up the good work

[michiganfarmer2]

Can't help, I prefer hands on. I try to run constant draw, I walk around the evaporator constantly, I check the head tank level often, I check sap in flow often. I do not trust some things to automation where a little glitch could ruin a pan and lots of syrup.
same here. I just really enjoy staying busy runnign the evaporator

[Toblerone]

I have released this project to the internet. Feel free to download it, improve it, make your own, etc. Please commit any changes back to the repository so we can all benefit. Schematics and firmware source code can be downloaded here: https://github.com/DCToblerone/Maple-Syrup-Controller

Just remember it currently in a quite unfinished state right now.

Haynes, that's funny about the sensor that calls a cell phone. Totally something I would have done.

Oh and I've attached an image of the schematic so far:

[twofer]

A couple things I have incorporated into my evaporator controller is a barometric pressure sensor and thermocouple amplifiers. I'm currently working on the code to have it automatically adjust the draw off temperature. This year due to time constraints I'm only going to have it display the draw off temperature on an LCD screen. Next year I will incorporate the solenoid valve to automatically draw off. The thermocouple amplifiers are going to monitor the combustion and flue temps. This way I can tell when I need to fire as well as go back and view the performance over the long term.

I'm also working on a separate sap controller. It has a vacuum sensor, ultrasonic range finder, and Dallas 1-wire temperature sensor. The vacuum sensor will monitor the vacuum and turn on a second pump if the level drops below the threshold. The ultrasonic range finder will monitor the collection tank and report the number of gallons. The Dallas 1-wire temperature sensor will monitor the outside temperature. This will allow the microcontroller to turn off the vacuum pumps when it is too cold and turn them back on when the bush warms up. It will also open up a solenoid valve to drain the transfer pump when it gets too cold to prevent damage to the pump. Eventually this controller will be hooked up to a remote database to log its readings and report critical events via text message to my phone.