Google docs link

 

This is the first charge of the new battery pack using the cells from the Chevy Volt.  Generally it charged perfectly except that it never reached the Vhi cutoff voltage of 50.4.  Maybe this isn’t a bad thing?batterycharge

I thought that lithium batteries would continue to draw and needed to be cut off when they were full.  In this case the current just dropped off to almost nothing as the voltage neared the cutoff.

 

2014-09-17 20.28.37

 

Pi Motor

In preparation for the pi class I wanted to get a motor running and found this excellent tutorial:

http://www.raspberrypi-spy.co.uk/2012/07/stepper-motor-control-in-python/

It works great once I realized the motor has a 64:1 gear reduction and  you need kilo-steps to see it moving.  Also while the code was very simple it looked it was written in C.  I decided to make it more pythonic:

#!/usr/bin/python
# ___ ___ _ ____
# / _ \/ _ \(_) __/__ __ __
# / , _/ ___/ /\ \/ _ \/ // /
# /_/|_/_/ /_/___/ .__/\_, /
# /_/ /___/
#
# Stepper Motor Test
#
# A simple script to control
# a stepper motor.
#
# Author : Matt Hawkins
# Date : 11/07/2012
#  Changes to be more pythoning  8 November 2014
#
# http://www.raspberrypi-spy.co.uk/
#
# Import required libraries
import time
import RPi.GPIO as GPIO
# Use BCM GPIO references
# instead of physical pin numbers
GPIO.setmode(GPIO.BCM)
 
# Define GPIO signals to use
# Pins 18,22,24,26
# GPIO24,GPIO25,GPIO8,GPIO7
StepPins = [24,25,8,7]
 
# Set all pins as output
for pin in StepPins:
# print "Setup pins"
GPIO.setup(pin,GPIO.OUT)
GPIO.output(pin, False)
 
# Define some settings
StepCounter = 0
WaitTime = 0.020
# Define simple sequence
Seq1 = [[1,0,0,0],
        [0,1,0,0],
        [0,0,1,0],
        [0,0,0,1]]
 
# Define advanced sequence                                                                                                                           
# as shown in manufacturers datasheet                                                                                                                
 
Seq2 = [[1,0,0,0],
        [1,1,0,0],
        [0,1,0,0],
        [0,1,1,0],
        [0,0,1,0],
        [0,0,1,1],
        [0,0,0,1],
        [1,0,0,1]]
# Choose a sequence to use
Seq = Seq1
while True :
    StepCounter = 0
    for step in Seq :
        for pin,phase in zip(StepPins,step) :
 
            if phase :
                # print " Step %d Enable %i" %(StepCounter,pin)                                                                                      
                GPIO.output(pin, True)
            else:
                GPIO.output(pin, False)
 
            StepCounter += 1
 
            # Wait before moving on                                                                                                                  
            time.sleep(WaitTime)
 

home.newts.org is a tiny  Raspberry Pi Linux  computer.  Currently it runs pyweather to connect my Davis Vantage Pro2 weather station to wunderground.com.  It also runs my tf mud client in a screen session and has a Cherokee web server that consolidates some information about the house and the solar power generation.

http://home.newts.org:8088/cgi-bin/home.py

The page uses python to get XML data from the Vera Z-wave controller and thermostat and HTML data from the Enphase Envoy gateway controller.

#!/usr/bin/python
 
import xml.etree.ElementTree as ET
import urllib2
import re
from bs4 import BeautifulSoup
import time
 
page = open('index.html').read()
 
now = time.localtime(time.time())
day = now.tm_mday
year = now.tm_year
month = now.tm_mon
 
# get the inside temperature
#
vera = 'http://192.168.1.4:3480/data_request?id=lu_sdata&output_format=xml'
vera_xml_data = urllib2.urlopen(vera).read()
root = ET.fromstring(vera_xml_data)
 
units = root.findall(".")[0].attrib['temperature']
thermostat = root.findall(".//devices/device[@name='Thermostat']")[0]
temperature = thermostat.attrib['temperature']
setting = thermostat.attrib['heatsp']
inside_temperature = 'Temperature = %s°%s Thermostat = %s°%s' % (temperature,units,setting,units)
 
# Get the solar production data
#
solar_home_page =  urllib2.urlopen('http://192.168.1.232/home').read()
solar_production_page = urllib2.urlopen('http://192.168.1.232/production?locale=en').read()
 
solar_re = re.compile(r'<!-- START MAIN PAGE CONTENT -->.*<!-- END MAIN PAGE CONTENT -->', re.MULTILINE+re.DOTALL)
 
solar_home = solar_re.findall(solar_home_page)[0]
solar_production = solar_re.findall(solar_production_page)[0]
 
soup = BeautifulSoup(solar_home)
tables = soup.find_all('table')
solar_statistics = tables[1]
 
solar_data = """
%s<br>
%s<br>
""" % (solar_statistics,solar_production)
 
# this was an attempt to display the nice graphs from wunderground.com
# it works if you go to wunderground.com first to trigger the file to be
# created but won't work otherwise.
#
graph_data = '<img src="http://www.wunderground.com/cgi-bin/wxStationGraphAll?day=%d&year=%d&month=%d&ID=KNHNASHU20&type=3&width=500&showtemp=1&showpressure=1&showwind=1&showwinddir=1&showrain=1">' % (day,year,month)
 
graph_data = '<h2>%s</h2>\n%s' % (time.asctime(now),graph_data)
# grr graph data generation has to be triggered by hitting wunderground
graph_data = ''
 
# Generate the web page from the template
#
print 'Content-type: text/html\n\n'
print page % (graph_data,inside_temperature,solar_data)

 

 

This isn’t a book but not sure what it really is at all but here’s some words:

 

Captchalogue

Sburb

Fetch Modi

Equip

Sylladex

Pesterchum

 

 

 

There’s stuff being circulated on FB now about radiation levels from Fukushima increasing in the US and about the EPA (Obama!) raising their safety limit instead of dealing alerting people and dealing with it.  I wanted to find out what is really going on.  Or at least spend an hour to see what I could learn.

First, the EPA did release a draft report to raise the safe limits on certain exposures last year although it doesn’t seem to be a response to recent events or political pressure but bureaucratic and scientific views that started a decade earlier.  This will take a lot more time to untangle so I will just leave that off here with the Forbes link.

Next up, are we seeing more radiation here from Fukushima and should we worry?  Fallout from nuclear testing in the 50’s and 60’s peaked before the test ban treaty.  It has come back down since then.  My general feeling is that the sky is not falling that as horrible as the disaster is the global effects are less than Chernobyl and nuclear testing in the 50s and 60s.

radiation

To look at this myself I got some historical data collected in Concord NH since 1981 and graphed it to the right.  This big spike is apparently Chernobyl and there is no large spike to the right since Fukushima.  The small spike is before(?) and there could be a little more amplitude to the noise since.  This is just collection point and there are some anomalies in the data set (spike at the beginning? flats around 09 maybe the collector was broken?).  My general conclusion is we are not seeing a noticeable effect  in the North East.  The Pacific coast or maybe other areas could of course see something different depending on the wind patterns.

Just for comparison I thought I would look at the data that I collected myself.  I keep a Gamma Scout  Geiger counter in t

2014-01-12 14.06.32

he basement to monitor the radon.  But, the software is is having trouble decoding the data.  Until I get that sorted I just have the government data.

 

 

I used to believe that I couldn’t really get into solar at my house because of the angles, trees etc.  But now I see they have micro grid-tie inverters (GTIs)  on the order of 100s of watts so that small systems are practical.  In some cases the inverter is even part of the panel.    So I think I can get a few 250 watt panels to offset a little of my energy usage.  The nice thing about these AC panels is that they are stand-alone and able to scale by simply adding more panels.

 

To compare panels I have a google docs sheet.  In trying to determine how much power I might expect to get out of the panels I made a guess of the amount of sun on average and also a “performance factor” which is real world efficiency based on angles and weather, etc for our latitude and weather patterns.  I made a guess of 8 hours and 60%.  The Watt’s have a great solar array and lots of real time data.  Looking at their yearly data I calculated a “performance factor” of  about 40%.  And in thinking about it more the average daily sun doesn’t matter in my spreadsheet.  It is already factored in without knowing the hours.

 

This article is just the starting point and has the links to my data sources and calculations.  I still need to research the tax incentives and ponder the different options for panels and inverters.  The built in GTI and racking is nice but expensive.  The external Renogy ones have an optional internet interface (gizmo!).  More on the options later.

 

 

2013-12-14 23.53.17

Sorry, just some set up links right now…

 

http://alexba.in/blog/2013/01/06/setting-up-lirc-on-the-raspberrypi/

 

http://learn.adafruit.com/assets/5909

 

 

 

 

 

 

It wasn’t a UFO actually but a government spaceship of some kind that crashed.  I was driving in some Western state and saw it crash land and I thought it would be a great idea to take some pictures with my cell phone.  There was like a traffic jam and I knew the government agents would confiscate cell phone photos.  Then I thought, no problem, the photos get uploaded to the cloud on G+ and DropBox.  Then in the dream I got really worried because the NSA would of course know that and that it was me.

So then some thinking in the dream how to handle it.  The solution was to have a spare uSD chip and swap it in the phone after I took the picture and then hide it in my shoe.  Brilliant plan actually.  Also in the dream I went on Facebook and G+ and posted that I was in no way thinking of killing myself and if it looked like I did then I had been assassinated by the government.

 

 

Links:

Patch meeting article

Legacy playground site

 

Objections to the park:

  • No tree cutting
  • No Paving
  • No lights
  • No fences
  • No bleachers

Questions:

  1. Can the location really meet ADA requirements without paving and grading?
  2. Disabled parking?
  3. Will there be swings?
  4. Guarantee on the objections (above)?
  5. Are there really no other parks in Nashua that can use a new playground?

 

 

 
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