There continues to be great interest in hacking weather sensors on the Pi. A while ago I wrote a ‘How-To‘ for the AOSONG AM2315 temperature/humidity sensor that was quite popular. Today I have released another ‘How-To‘ for the AM2315’s siblings – the AM2302, DHT11, and DHT22 sensors.
I have found that experienced Pi/Linux users can get these sensors up and running in a very short time. For many hackers new to the Pi and or Linux, it is a challenging learning process, sometimes even intimidating. Sopwith’s ‘How-To‘ series are guides designed to help these folks succeed in their Pi project.
Each ‘How-To‘ includes screen shots for nearly every step of a project. Although this takes some work and makes the documents longer, I have found it is these images that help Pi enthusiasts understand each implementation step.
You can download the ‘How-To‘ below. The Zip file also contains the modified test Python script described in the document.
Post a comment if the ‘How-To‘ Series helps you with your projects. Improvements, edits, bug reports, and requests for other ‘How-To‘ topics are most welcome.
There is a kid out there who would love to help you hack your Pi.
Ol’ Sopwith was fortunate enough to order a couple of Pi 2’s before they quickly sold out. I received them on February 4th and immediately started to hack.
I did not expect this news about my new Pi’s. They are very camera shy. There is a published report on the Register UK web site that the Pi 2 does not like its picture taken. It seems that Pi 2’s will crash when you take a photo of them using a Xenon flash. How crazy is this?
I did what any good hacker would do – recreate the problem. I whipped out my trusty old Canon PowerShot A650 and took a picture of my Pi 2 when it was running a temperature sensor test suite.
Sure enough, the instant the flash went off my little Pi went to sleep. Dead sleep. Some YouTube videos show their Pi’s rebooting, mine shutdown completely. The crash did not affect my Pi; it immediately booted fine when I cycled power.
The Raspberry Pi Foundation released another new Pi last week. Officially called the Pi 2, the new changes are all about performance. The form factor is exactly the same as the B+. The big news is the use of an ARMv7 core processor that has 4 cores plus a boost of additional RAM to 1 GB. Initial reports say this Pi is 6X faster than its siblings. Wow!
Photo courtesy Adafruit via Flikr
One of the great things about the Raspberry Pi Foundation is you never know what they are going to do next. In November 2014, they released a + version of the Model A. It has the extended GPIO pins (40) of its big sister the B+. It is also smaller than any other Pi at 65mm in length.
In order to shrink the footprint, the A+ has no Ethernet port, a single USB port, and 256MB of SDRAM. This not only reduces the physical size of the device, but also the amount of power it consumes. I recently purchased an A+ with the very cool Pibow Royale enclosure. What a beautiful combination of high tech and art.
Raspberry Pi A+ with Pibow Royale enclosure (Photo courtesy Adafruit Industries on Flickr)
I am sure many folks are wondering why bother with a a Pi that is so… ‘legacy.’ For me, this is exactly what I was looking for. Small, simple, lightweight, and capable. Trying to jam the original Pi’s into security camera enclosures has been a headache for me. Not anymore.
Also, the low power requirements of the A+ make it much easier to power the device for long periods of time using batteries or solar power.
The folks at the Raspberry Pi Foundation are not only mad scientists – but geniuses as well. Tip of the hat to you all.
Stay tuned for some of the great projects I plan for this fantastic Pi.
One of the great things about living in London is the fact glossy Linux magazines are so cheap. These magazines are published in the UK and sell in stores for about 6 Quid. The same magazine in the US is $15+ due to the exchange rate and shipping costs. I buy one every chance I get.
I came across a very interesting article in the December 2014 issue of Linux Magazine titled, “Plane Spotting.” Written by Charly Kuhnast, the one-page article describes how to use a USB DVB-T device to capture airplane traffic and plot it on a Google map. What a cool idea! Ol’ Sopwith decided to purchase a DVB-T and see if it would work on the Raspberry Pi.
Being far from home and living in London is very interesting. As a hacker, maker, and hobbyist from the US, a Radio Shack or an order from Mouser, Adafruit, etc is taken for granted. Things are different here.
There is not a Radio Shack nearby. The nearest equivalent is Maplin and these stores are everywhere. Every time I walk by one – I ‘pop in’ as they say here.
Last Saturday I ‘popped in’ to one and found a very interesting electronic kit. The Velleman Digitally Controlled FM Radio (MK194). Velleman is a Belgium based company that makes all kind of neat stuff. The kit was on sale for £12. How could I resist?
This kit is about as close as you can get to re-living the good-ole’ days of Heathkits. In the 60’s and 70’s Heathkits were all the rave among us geeks. I built a digital alarm clock that worked for more than 25 years. What is the big deal? Well, I was 14 years old when I built this clock. And it served as my alarm clock until I was 39. Every day – it was there. The power supply finally failed and its service ended.That my friends, is the definition of loyalty. Hand built and reliable.
Anyone that ever built a Heathkit remembers the yellow assembly manuals. They are legendary for their quality. Oh the joy of a Heathkit!
Heathkit Digital Clock
In my recent posts I hacked a BV4618 LCD to prepare it for use in my Tastic RFID project. Now that I have the BV4618 working and an improved and simple code library (sopBV4618_S), we return to the Tastic tool. If you are not familiar with the Bishop Fox Tastic project you can read about it here.
Ol’ Sopwith again wants to make it clear that I am not interested in the dark-side of RFID hacking. Nor do I encourage anyone to do so. The goal of this project is to learn about RFID and how it all works. Fascinating stuff.
After researching the Tastic RFID documentation I ordered three PCB’s using the Tastic project PCB documents. The vendor I used was OSH Park. Highly recommended outfit that does great work.
In Part-2 of this blog post series I provided a detailed ‘How-To’ for new users of the ByVac BV4618 LCD for their Arduino projects. It is clear to me there are plenty of Arduino hobbyists who want to hack LCD’s and need a simple way to wire them up and write to them.
The ByVac BV4618 LCD is a great choice. You can actually get it up and running with three wires – V+, Gnd, and Tx. Writing text to the display is pretty straightforward using the BV4618_S library. The library is useful, but Ol’ Sopwith does not think the class is easy enough to use for beginners.
To solve this problem I extended the BV4618_S class library and created a new class named sop4618_S. The class is brain-dead simple to use and it hides all the complexities of the VT100 code sequences.
In Part-1 of this blog post series Ol’ Sopwith described the ByVac BV4618 LCD and how to wire it up to an Arduino Uno. If you are interested in how to program an Arduino to talk to this LCD, pull up a chair and let’s get started.
I wrote up a detailed implementation guide for the BV4618 LCD that walks through the entire process to get the LCD into one of your cool Arduino projects. If you are new to the Arduino and want a quick guide on how to setup the developer IDE you can follow this guide.
Arduino ‘How-To’ Series
My previous post describes my new venture into RFID hacking using a Tastic RFID stealer. The Tastic gadget requires a serial 4×20 LCD to display a proximity cards site code and serial number. I purchased a ByVac BV4618 LCD as a replacement to the LCD listed in the Tastic specifications due to local availability.
As Sopwith always advises, the first thing you need to do with a new gadget is to download the datasheet. You can find it here. The internal controller/driver of the LCD is a Hitachi HD44780. This very popular device can be found in all types of LCD applications. The BV4618 piggybacks on the HD44780 providing a very convenient communication interface.
The BV4618 provides three interfaces. A serial interface provides support for both TTL and RS-232. This means you can connect a MCU such an Arduino or Raspberry PI, or use 12V serial connections to a serial port on a PC. There is also an I2C interface and support for a small numeric keypad.