Here’s the thing.  When I wake up in the morning I love to use my treadmill desk and do computer stuff.  Right now, I could do computer stuff but my mind is fixated on getting the esp8266 shield working.  With that said, I am letting this artificial barrier get in the way of just getting stuff working.

I decided to test the code for reading the sensors.  Here are the results:


The temperature seems a little high, but my focus is on the CO2 readings.  They stay within the 700ppm level.  I expect a level closer to 400ppm.  What I’ll do to “fix” this is use the calibration code from Seeed studio’s CO2 sensor entry on their wiki.

With that said, a challenge I have with all these sensors is calibration.  How do we know they are accurate?  Is the temperature truly what it says it is?  Due diligence should have me validate each reading with at least a separate meter.  Lucky for me, I did get a CO2 meter after learning the benefits of CO2 levels of ~ 1200ppm to photosynthesis.

I got the Extech Indoor Air Quality, Carbon Dioxide (CO2) Meter from Home Depot.  I tried less expensive ones but they broke.  


Given the meters used by the professors in the courses I took, heck the price of this one was a bargain.  After all, we are only as good as our tools.  With that said, I got this meter because – while expensive for a hobbyist – accurately measuring the CO2 is important.  Also, I am very happy with the Extech DMM I have.  The challenge I have is if I am not powering it from the wall, it takes 6 AAA batteries.  Unfortunately, the ones I had in stopped working…on the plus side they hadn’t corroded and ruined the device.  

After calibrating the meter, I got readings of 580ppm CO2 level, 68.4˚F temperature, and 40% humidity.



Pressfit Connections – What a Cool Idea

This was on


 The Growth Chamber Housing



I’ve made progress with the Growth Chamber Housing.  The front has clear vinyl with velcro so it can be opened to get to the plant leaves.  I went wild…while I was in the line to buy stuff at Jo-Ann Crafts, I got Troll Duct Tape.  


I decided to tape the top of the housing with it:


It is pouring rain here today so I lazed out of calibrating the Grove CO2 sensor.  I’ll do that tomorrow.  In the meantime, I was thinking through what needs to be automatically turned on and off:

  • CO2 feed
  • LEDs
  • Pump.
If I leave the pump on all the time, the plant roots will drown.  Roots need a lot of oxygen so I’ll turn the pump on a bit every so often.
That’s it for today…didn’t hear back from Sparkfun…hmmm….