Thursday, March 24, 2016

34: A Real Installation -- Practical matters

Some things I've learned since I first installed a Photon system in My granddaughter's 100' x 30' hoop house last summer:

1. The environment is tough. The temperature swing in a single day can be over 50F. Humidity often approaches 100%. UV attacks plastic, e.g.: the heat-shrink tubing over the wire splices.

2. I have wire runs over 70'. I've learned to use only stranded wire: solid conductor can break -- and it has.

3. I used a single Photon ($19) in the hoop. It's backed by a Raspberry Pi 100 miles away. Attached to the Photon are 3 temperature sensors, 2 soil moisture sensors, plus switches for an outside deer fence and irrigation valves: about $90. But the wiring cost more. I should have used multiple Photons and shorter cable runs. More complicated programming, simpler/cheaper cabling.

The Photon has been reliable. Not the rest. For my initial cabling I ran two Cat5 8-conductor cables (solid copper) to the middle of the hoop house and spliced (solder/heat-shrink/non-conductive caulk) 2 or 3 wire cables to the sensors.  That failed -- not always hard failed, some intermittent. Been replaced with straight (unspliced, more expensive) runs.

Tuesday, March 22, 2016

33: Computer Farming

If you've followed my blogs you'll know that I involved myself in the Raspberry Pi and Arduino initially help grandchildren who insist on farming. See my post 2

I've recently come across the dirtless farming work done at MIT. See--


The MIT system is open source so I visited their github site and downloaded the source code. Interesting. There's a bit of overlap with my much more modest setup. I haven't finished snooping, but it appears that I have used the same sensors as they have -- temperature, humidity, soil temperature, soil moisture, irrigation switching. For testing, I have also programmed a CO2 gas sensor and photo sensor. They also have code for a pH sensor. I've been thinking about that one. There's a big range of prices.

Their system utilizes Arduino Megas and a Raspberry Pi. My system uses Photons and a Raspberry Pi. Note: the Photon is as powerful as a Mega. Because of the Photon's "cloud" my Pi is 100 miles away.

Anyway. Their setup is worth studying.

Sunday, March 6, 2016

32: Update

My current Particle position is: 1 Core, 5 Photons and as of yesterday, 1 Electron.

nice packaging

I didn't order during their Kickstarter campaign but right after. Today, I went to to get started. Authorizing the SIM card seemed to go fine. My first problem was trying to connect the cell service antenna. Very tiny plug, very difficult, especially with trifocals. Finally seemed to work -- don't know how.

Left to right: USB power cable, battery, Electron, wifi connector (taped down 'cause I don't want to have to do it again), antenna wire and antenna.

Second problem: My phone shows AT&T 2 or 3 bars (probably 4G, but probably 3G as well). But as in above image, the Electron doesn't connect. The green LED just blinks.