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jennajane's picture


Member for
5 years 8 months


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# of Forum topics submitted: 7

# of Comments: 13

Stream of Forum Topics

In 50 characters or less... Posted by Post datesort ascending Last comment Number of Comments # of Comments new to you
Great Idea jennajane Thursday, January 1, 2015 - 2:55pm Thursday, January 1, 2015 - 2:55pm 0
The Ultimate Eggmobile jennajane Monday, April 14, 2014 - 8:42pm Wednesday, April 16, 2014 - 9:37am 3
Nice write up jennajane Thursday, March 13, 2014 - 7:50pm Sunday, November 9, 2014 - 6:43am 5
barrel root washer jennajane Wednesday, August 21, 2013 - 10:06am Tuesday, February 4, 2014 - 8:32pm 8
Great Idea jennajane Monday, August 5, 2013 - 8:08am Monday, August 5, 2013 - 8:08am 0
More water at my wash station jennajane Tuesday, June 11, 2013 - 9:55am Monday, July 29, 2013 - 8:47pm 2
Controlling lights in seedling room jennajane Wednesday, February 27, 2013 - 5:30pm Wednesday, March 20, 2013 - 2:39pm 1

Stream of Forum Comments

jennajane's picture

I have also wanted to know when the electricity goes out in the greenhouse, because that means the heater doesn't work. I did this simply with the "normally closed" contacts on a SSR (solid state relay). As long as there is power, it holds the contact open, when the power goes out the contacts close and ring a wireless doorbell in the house. I know that eventually the relay may fail being energized all the time, but after a year I have had no problems.

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Wow, I like that this type of project is getting more interest. I really like the project post by Ed, thanks Dorn. I have been going the other way and replaced my Uno with a Mega board and started to ask it to do more things. I am still running an onboard analog temp sensor along with 2 digital temp sensors attached to a single pin. I have added three relays to control the furnace, ventilator and a heated greenhouse table. The best part about my project is the wireless door bell that rings in the house when temps go out of range or the power goes out.

This winter I am hoping to get a wireless display to our house so it is easy to monitor. Should be pretty straight forward with a couple of xbees. One day I would like it all sent to my smart phone, but I feel like text messages is not the best way for me. I could easily get my Mega board a wifi signal so it would be easier to make the jump that way then over cell signals.

Let me know if you have any specific questions? I would be happy to help, although things are pretty busy on the farm right now, these are usually winter projects for me ;)


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Yup, all the rest of our greenhouse tables sit on saw horses too. I had a spot for this one to be a bit more permanent, and with 300lbs of sand in it, I didn't want to take it down. the pea gravel probably works too, for me I was trying to create a large thermal mass to avoid temperature fluctuations. To add a circuit like this to my microprocessor costs me the price of a relay and temperature probe $25 for the fancy ones, and then I can log the temperature in the table, know how long the heating coil is on under different temperature settings, and patch it into the alarm in case the temps get too high or too low. Plus I am a bit of an Arduino geek.

Post up a picture or two to help out others that are thinking about doing the same thing.


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Hi Louis, thanks for the nice words. I have revamped the temp data logger I wrote about last year, it is now based on a mega board, controls heating and ventilation in our greenhouse, as well as the germination table I also wrote about here. I have also added a wireless doorbell as an alarm if the temps go out of range or if their is a power outage. I am hoping to add an LCD display in the greenhouse and am thinking about how to get another LCD in the house, it sounds like this would be perfect application for your bee.

I am curious about your bee, it looks like it has a lot of what I want in a board, but upon first inspection it doesn't look like there are many digital pins. I out grew my Uno in the greenhouse pretty quickly with just a few sensors, relays, and logging capabilities.

I am excited about the egg mobile, for sure I will have some kind of microcontroller in it. I like the idea with the food dispensing, make it kind of like a giant gumball machine.


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Hi Geoff, welcome to Farm Hack, I am part of a cooperative organic mixed farm near Lachute, QC. I am interested in participating / organizing Farm Hack events out here. Do you have info on the event coming up in May at Jean-Martin's farm?

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I have never done this before but I uploaded them to the 3D warehouse, you can find them by searching for "Barrel Wahser". Yes please feel free to add them to the Farm Hack collection.

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Well things are finally slower and I thought I would give a little update on this project. The garage door opener didn't work. The motor is not rated for continuous use and would quickly overheat if I ran the motor constantly. I then bought an old electric motor from the local antique dealer, and attached that to the gearbox of the garage door opener. This worked well for a while, but the plastic gears from the garage door opener eventually gave out, and I was once again in need of a new fix. I went back to the same antique dealer as before I had eyed up what looked like a worm gear. I once again remade the mounting brackets for the motor/gearbox, covered it all with a bucket and it worked beautifully, this fall we washed a several thousand pounds of carrots, beets, parsnips, potatoes, turnips and rutabagas. I have a bunch of pics I will use to document this build as time permits.

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Hey Joel, thanks for your interest in this, you have to remember that 08/21/13 is a busy time for farmers in the north, I was hoping for some feedback on the design before I started cutting and welding. Something like the gears on a garage door opener will never hold up or garage door openers aren't suitable for continuous use (see post below).

jennajane's picture

Ok, I am not sure which part you hope will be simple, lets focus on the toaster oven because that will take the most electricity. You have to know how much power you are going to need. An average toaster oven uses 750-1100 watts. So you will need an inverter that can handle that large of a load, lets call it 1000 watts. Next is the battery, an average car battery doesn't like to be drained and recharged all the time. You need to look to a deep cycle or marine battery. A good deep cycle battery is rated for about 100 amp-hours (that means it can do 1 amp for 100 hours or 100 amps for one hour). We also know that Watts=volts x amps, so 100 amp-hours at 12 volts is going to give you 1200 watts-hours. So a good battery will only run that toaster oven for about an hour. So you need to know how many minutes to toast the cheese crisp and how many you want to sell in a day.

So what if it is also hooked to a solar panel? well the solar panel will be rated in watts, and you need something to charge the batter equal to the amount of watts you are using. This is likely going to be a big panel, or take a lot of lot of time.

Finally, I would recommend a fossil fuel. Propane, is the most efficient...find a way to make the cheese crisps with propane and just run lights (LEDs) and music with the battery and solar panel.

I hope this helps. I am not an expert, but my dad is and a bit has rubbed off on me.

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Ok, so if anyone is following this I finally got it all hooked up and tested today and it works!!! I tested it out by filling a 20L bucket at one spray station with and without the pump, and the filling 2 buckets simultaneously at 2 spray stations. See attached graphic. I was able to fill one bucket 35% faster with the pumping setup than before and 2 buckets 45% faster. I was even able to fill 2 buckets with the pump faster than 1 bucket without the pump. I did, however, go a bit over my budget.

$230 - 3/4hp Shallow Well Jet Pump
$140 - 250 gallon water tank
$30 - electric float switch
$145 - all the plumbing filltings

I hope this helps someone. I have a third spray station roughed in, but haven't set it up yet. If anyone is curious you can see some pics of the building of the wash station on our facebook page


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Ok, I think this might work, I found a 3/4 hp jet pump on sale, and drew up a schematic for how it should work. The jet pump comes with electronic pressure control, which I am curious to see how it works. The idea is...

1) Under light use the pump in the house provides enough pressure that the jet pump doesn't kick in.
2) The water cube is always full because of the float valve, if the cube goes empty then the float switch cuts the power to the pump.
3) Under heavy use at the wash station, the jet pump turns on, closes the check valve and provides enough pressure at the wash station.

I am hoping to take it to my local plumber tomorrow to see what he thinks, but the veggies are starting to come in from the field and we are already beginning to feel the lack of water pressure when there are 2+ farmers washing.


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I moved things forward on the onion seedling room project. It took a while but I finally got an arduino sketch that works to control the powerswitch tails. Also after some net searching it seems 14-16 hours is a good amount of time to leave the lights on. I connected the 'in+' of the powerswitch tails to digital pins 8 and 9 and the 'in-' to ground. The stripped down sketch for the timer looks like this:

// Program .....: RTC_Relay
// Author ......: Jenna Jacobs (adapted from Joe Pitz, Objetek Systems,
// Copyright ...: Creative Commons, CC BY-SA
// Description .: Turn on and off two power switch tail 2s
// Date Created.: 3/20/2013
// Usage and dependencies:
// Variables are used to set start time and end time.
// Times are based on 24 hour clock, i.e.:
// 1:00 pm = 13:00 and Midnight is 00:00
// Start time must be less than end time and both times must fall within the
// same 24 hour period.
// Code uses RTCLIB, a branch provided from:

 #include <Wire.h>
 #include "RTClib.h"

 RTC_DS1307 RTC;

 // Setup Start and End TImes
 // This is where you define your start hour and start minute times

 unsigned int StartHr = 7;
 unsigned int StartMin = 30;

 unsigned int EndHr = 22;
 unsigned int EndMin = 30;

 // This is where we create a combined time in Day minutes (the number
 // of minutes since the start of the day)
 unsigned int DayMin = 0;
 unsigned int StartDayMin = (StartHr*60) + StartMin;
 unsigned int EndDayMin = (EndHr*60) + EndMin;

 // ledPin used for debug using Arduino on board LED.
 int ledPin = 13;

 // Pins used to control powerswitch tails (pst)
 int pstPin1 = 8;         // Set our LED pin
 int pstPin2 = 9;         // Set our LED pin

 void setup () {

     pinMode(pstPin1, OUTPUT);
     pinMode(pstPin2, OUTPUT);

     RTC.adjust(DateTime(__DATE__, __TIME__));

   if (! RTC.isrunning()) {
     Serial.println("RTC is NOT running!");
     // following line sets the RTC to the date & time this sketch was compiled
     RTC.adjust(DateTime(__DATE__, __TIME__));

 void loop () {
     DateTime now =;

DayMin = (now.hour()*60)+now.minute();

     Serial.print(now.year(), DEC);
     Serial.print(now.month(), DEC);
     Serial.print(, DEC);
     Serial.print(' ');
     Serial.print(now.hour(), DEC);
     Serial.print(now.minute(), DEC);
     Serial.print(now.second(), DEC);
     Serial.print(" to ");

     // Check status of light
       if (DayMin >= StartDayMin && DayMin < EndDayMin)  
         // turn on lights      
         digitalWrite(pstPin1, HIGH);
         digitalWrite(pstPin2, HIGH);

         Serial.print(" Lights On"); 


         // turn light off
         digitalWrite(pstPin1, LOW);
         digitalWrite(pstPin2, LOW);

         Serial.print(" Lights Off");  



I have incorporated this into the temperature datalogger I have documented in the tools section and will add documentation there.


jennajane's picture

Hi, I started farming last year in Quebec, Canada and had a big year. I am the founding member of a cooperative farm with 2 other women. I am in charge of machinery and infrastructure here on the farm (among other things). Last year I led the building of a 3000sqft greenhouse, a veggie wash station, a 140 sqft cold room powered by 2 cool bots, a 150 sqft chicken coop and purchased $12k in machinery. I am hoping this year is a bit slower, but have dreams of buying/building a bit more equipment, a bed former, a toolbar with sweeps, building a pedal-powered root washer, and a pedal-powered salad spinner. I am interested in Arduino based projects to control things all over the farm, but especially in the greenhouse.

We run an certified organic CSA, and currently have about 40 laying hens, and raised 2 veal cows last year. We do a 19 week summer season and a 14 week winter season. We are La ferme cooperative aux champs qui chantent (Singing Fields Cooperative Farm).