- built using $78.50 worth of widely available parts
- no soldering required for assembly, it's "plug and play" thanks to USB
- designed to connect to WiFi but can also connect to cellular networks
- plans for automation and more plug and play sensors in the future
In the past few weeks Stefan Unterhauser and I have been working on a new design for Fido that is easy for farmers to build and deploy while maintaining a parts list that has a steady supply so that Fido can scale to the many farms that need it. We started with a new design that uses a credit card sized $35 Linux computer known as the Raspberry Pi, a $16 Temper1 USB temperature sensor, and a $15 USB WiFi dongle. This combination allows us to remove the need to solder together the many parts the Arduino based design required. We also removed the hard requirement of a Motorola C168i which is out of production and only available in limited quantity as a used phone and replaced it with an Internet connection dependency that sends text messages as email (free text messages!). We built a shiney web app that is hosted from the Raspberry Pi that users use to set up the WiFi connection, min and max temperature limits for alerts, define their alert phone number, and many other things. Also in the works is the "lite" version of Fido that we are building around Android and the Thermodo Temperature sensor that snaps into the audio jack. The design has the least potential for expanding but will be the easiest way to get started with a temperature alarm that sends text messages.
At the iFARM event at Tuckaway Farms in NH this year, we brought 14 Raspberry Pi Fidos that we had built. We managed to find new homes for 7 of them, 4 of which are now deployed at in one of greenhouses at Wild Miller Gardens. In the coming weeks we'll be writing documentation on how to build your own Raspberry Pi Fido and we're also thinking about doing a Kickstarter to sell preassembled Raspbery Pi Fidos.
To understand why we've been working so hard on other Fido models, it's important to compare the different designs. Below you will find a design synopsis of the three Fido designs in existence. I rate each model on five different qualities that get a score of 1 to 5. The higher the number, the better I think that design does on that quality. Each design gets an total score. A total score does not necessarily indicate a better design for any particular farmer as each person will have to decide for themselves which qualities are most important to them. If you think my analysis is off or I'm missing some information, do let me know! We could use your advice.
- availability: The likelihood a farmer can acquire the parts list now, in the future, and at scale in case it becomes a popular design.
- buildability: The likelihood a farmer can assemble the parts list into a working unit.
- deployability: The likelihood a farmer can deploy the unit into an real life situation.
- usability: The likelihood a farmer will be able to manage the device in a deployment.
- expandability: The likelihood a farmer will be able to expand the device to do other tasks other than the original fido design goal.
Arduino based Fido
The Arduino based Fido is the original Fido model designed by Louis Thiery as lead developer and some help from R.J. Steinert and Ben Shutes. It is based around an Arduino that is listening to attached temperature sensors and then sending the owner a text message through an attached cell phone when an owner defined max or min is reached. The owner defines max and min temperatures by sending a text message to the phone the Arduino is attached to.
Raspberry Pi based Fido
The Raspberry Pi behaves as a Ground Server that listen to a USB temperature sensor. The Raspberry Pi broadcasts a website on the local network it is on which the user can use to define the minimum and maximum temperatures to be alerted on. When the minimum or maximum is reached, the Raspberry Pi emails a text message to the user's defined phone number. The goal of the project was to reduce the level knowledge needed to assemble a Fido. The design achieves this by using WiFi and Temperature USB peripherals that do not need to be soldered to the Raspberry Pi board. Because the design uses the Internet to send text message alerts, the design is built to easily configure a connection to WiFi networks. The Raspberry Pi based Fido was designed by R.J. Steinert and Stefan Unterhauser.
Android based Fido
The Android based Fido consists of an unlocked $50 Android phone and a temperature sensor that fastens to the audio jack. Minimum and Maximum temperatures are entered in a Fido Android app. When those limits are reached, the phone's internal text message capability is used to send the message. The design goal for this design was to reduce the complexity of setting up the device by using the Android App experience as opposed to the Ground Computing paradigm of using a Raspberry Pi.