Pi Real-Time Clock ‘How-To’

For Makers that need an accurate clock for their projects, the Raspberry Pi does not have one. In order to save costs and board space, a hardware clock is missing in all versions of the Pi. Fear not. There are many options available if you need an on-board clock for a project.

DS3221 RTC

I have written a ‘How-To‘ document that walks through the details of getting a real-time clock (RTC) up and running on a Raspberry PI. I know there are plenty of resources on the Web that show how to do this, but I like to take the extra time to write a complete document, not just a list of bullet points.

Makers that are new to the Raspberry Pi and its SBC brethren appreciate having the screen-shots that make it easier to follow along. As long as my ‘How-To’s’ help beginner or intermediate Makers create cool things, I will continue to write documentation.

You can download the ‘How-To here.

AM2315 Update

Hello to all my smoke-eating Maker friends. O’l Sopwith has a story to tell. In my February 1st post, I posted the pure Python source code and updated the implementation documentation for the ever-so-popular AM2315 temperature sensor.

I did this after receiving an Email from a fellow Maker who wanted to know why my sample AM2315 code did not work with Python3. The day after I published that blog entry, a comment was posted stating they could not get their sensor working. The AM2315 was visible in the i2cdetect test, but it would not return any data. The Python code crashed and burned.

About a week of communicating back-and-forth to troubleshoot the problem, this is what we did:

  • Turned on Debug mode in the python script
  • Made sure the device was wired correctly
  • Made sure the correct software was installed
  • Disconnected all other devices from the Pi
  • Ran the SwitchDoc Labs test script (same stack trace)
  • Ensured the Pi had a 2.0 amp power supply

About the same time this was going on, the mate who asked about the Python3 port downloaded and tested the new code. He could not get it to work either. Thinking he had a bad sensor, he set up a test harness and tested his sensor on an Arduino. It worked fine. After some fiddling around, he determined the MAXREADATTEMPT = 3 on line 23 was too small a value. He changed it to 10, and his sensor worked fine.

Continue reading

AM2315 Implementation Doc Update

After more than 5 years, I still get an occasional Email from Makers who ask questions about the Aosong AM2315 temperature/humidity sensor. I got one this week asking why my AM2315 python code did not work with Python3.

This nudged me to take a look at my code and figure out what it would take to get it to work with Python3. Next thing you know, I decided to remove the underlying dependency on any C code libraries and ensure my sample Python code works in both Python2.7 and Python3 without modifications.

To do this, I rely on two Python modules. The first is the great code written by our friends over at Adafruit. They have created a Rapsberry Pi GPIO code module written in pure Python. The second module is from the innovative folks over at SwitchDoc Labs.

I have updated the AM2315 Implementation Guide with the new changes. I also modified the SwitchDoc code so that it will work with Python3.

Now it is time for a rant. If you are a Python programmer, it is time for you to get serious about Python3 if you are still clinging to your Python2.7 worldview. All new code you write should be written in Python3. Python2.7 has an End Of Life date on January 1, 2020. There is a lot of 2.7 code out there that will work in Python3 with just a few changes. In fact, the only changes I made to get the SwitchDoc code to work was putting parenthesis around the print statements. EOR. (End of Rant)

You can download the updated implementation document with a code sample here. Thanks to Adafruit and SwitchDoc Labs for being a part of the Open Source community.

Home Automation Hacking Part-II

In Part-1 of this hacking series, I set the stage for an adventure in home automation hacking. My goal is to start small, grow a system over time, and share the experience.

To follow along on my openHAB adventure, instead of creating an enormous blog entry, I decided to document it in a PDF ‘How-To’ document. I have found these types of documents are highly valuable to those folks that are new to the Raspberry Pi and Linux, and/or those who have little programming experience. Download the PDF and configuration files below:

 

Here in Part-II, we explore my adventures with openHAB.

To learn more about openHAB, read Part-I of this series or head over to their web site. I started knowing nothing about openHAB, so I spent a lot if time in the documentation. Next, I burned an image of openHABian and fired it up on a Raspberry Pi 3.

In a couple of weeks of study and hacking, I have a working home automation system that is quite cool. Below is a view of my openHAB system as seen in a browser.

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Home Automation Hacking Part-I

Hello smoke-breathing brethren. Ole’ Sopwith is about to embark on another hacking adventure. This time it is all about home automation. Yes, it seems I am a little late to the party – but hey – at least I showed up!

There are two goals to this project. 1) To learn something new, and 2) To have fun. Wait a minute! Those are the goals of every Sopwith project!  Yes – but this project should be really interesting. In this multi-part blog series, I am going to compare the two leading open-source home automation platforms:  OpenHab and Home Assistant.

OpenHab is a Germany based open source project founded in 2010. It is written in Java and is based on the Eclipse SmartHome platform. It has a very active community with a very large pool of developers. It provides the ability to integrate hundreds of home automation devices, regardless of manufacturer or whether is it open or closed hardware. The cool thing about OpenHab is that it provides a mechanism to build a complete home automation environment and keep it private.

Home Assistant is another very active open-source home automation platform written in Python3. It also has a vibrant and active community. Founded in 2013 by Paulus Schoutsen, it began as a simple Python script to turn on some lights when the sun set.

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NatureBytes Camera Kit Part-IV

In my previous posts in this series (I-III), I added night vision capabilities to the very cool NatureBytes wildlife camera kit. As in all maker projects – improvements had to be made.

Once I placed the night-vision capable camera in the field for testing, I discovered the LISIPAROI IR light board cannot be used in the wild. The device is just not powerful enough. If is fine for close-up work, but outside? Forget it.

It was time to turn disappointment into action. Plus, if it worked out of the box – what fun is that? Time to get serious. As I searched the web, I discovered weatherproof 12V IR lamps are cheap. These are designed to be used with CCTV cameras, most of which are 12 or 24 VDC powered. I purchased a pair for around $16 USD. The one I chose is made by a company called Phenas.

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NatureBytes Camera Kit Part-III

In Part-I and Part-II of this blog series, I assembled the terrific NatureBytes Camera Kit and mounted it on a tripod.  I had to wait for parts to arrive before I could add night-vision to the kit. This blog post shows how I modified the camera kit so it can see in the dark.

The goal was to somehow mount and power the LISIPAROI IR light board while still maintaining the weather-proof integrity of the NatureBytes camera kit. The night-vision hack turned out to be pretty simple.

I found a small plastic box with a latching lid in the office supply aisle at a local Wal-Mart. It was designed to store paper clips on a desk, but Ol’ Sopwith had other ideas. The box was the perfect size to install a battery pack, trigger wire and IR light board. Continue reading

NatureBytes Camera Kit Part-II

In Part-I of this series, I introduced the NatureBytes KickStarter project and finally got around to building the kit I ordered in 2015. I want to hack it so I can capture photos/ videos at night. I need to identify what nocturnal animals are exploring my yard overnight.

The Camera Kit is simply – Fantastic! Details of the kit and the build instructions can be found here. The first thing that struck me was the quality of the bright green case. This thing is an engineering marvel.

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NatureBytes Camera Kit Part-I

On June 24, 2015, a NGO named NatureBytes began a KickStarter campaign to raise money for a wildlife camera kit based on the Raspberry PI. Based in Berkshire UK, west of London, this conservation group set out to encourage kids to get off the couch and explore nature.

Within a month, the campaign raised £34,164 from 303 backers.  This was 108% over the goal of £28,995.  At that time, Ol’ Sopwith was living in London and was one of 50 backers who pledged £85.

It was expected the kits would ship in December of 2015, but there were delays caused by the complicated molding process used in creating the cases. I followed the updates closely because I felt their pain. Anybody who has ever been involved in the injection molding process of plastics knows how difficult this can be.

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The AM2315 “How-To” – Updated

As promised, I have updated the AM2315 temperature sensor “How-To” document for modern times. The changes include:

  • The removal of the obsolete quickwire library that caused so much pain.
  • Removing quickwire also removed the dependency on Python3.
  • Added the very capable i2c library tentacle-pi written by lexruee.
  • Use of the Raspian Switch OS means these instructions work on any Pi.
  • Streamlined 6-Step process.

I have tested the new procedures on every Pi that I have in the drawer. This includes a Pi v1, v2, vA+, v3, and the Pi Zero. Yup – they all work using the same software and the same pinout. Sweet!

You can download the new document and test script here.

For all of you that have contacted me in the last couple of months trying to get your sensor working, I apologize for the delay in getting this document updated.

Sopwith