As part of my project; a small monitoring tool to monitor beehives dubbed ‘BeeSafe’ I have been designing and assembling a small printed circuit board – PCB, to collect all the sensors together.

Previous parts of this build can be found at:

http://www.mathewjenkinson.co.uk/beesafe-concept-development/

With the board printed and etched it was now time to solder on all the components and begin testing.

As you can see from the picture below; soldering is a skill I’m still to master!

Version 1 of BeeSafe PCB

Version 1 of BeeSafe PCB

Following what I thought to be a simple design I quickly found out that I had errors both in the pin layout and the physical spacing of the components used on the board.

The placement of the GPIO connector (13 x 2 lines of pins) meant that the board was in an awkward position and the cable pushed up against the accelerator / motion detector.

Physical component wise, the LED’s were situated too close to each other, meaning that when it came to solder them, they were all on-top of one another.

Its important to stress that while this PCB hasn’t been a success, it hasn’t been a failure either. This PCB came from a new manufacturing process where I used a laminator and gloss paper as the toner transfer method. As you can see from the image above the process itself was a success!

From here, the PCB design will go back to square one. I want to switch from using Adobe Illustrator to a proper PCB design software such as Eagle PCB which will allow me to design better more complex boards that can include things like silk screen’s and will be easier to scale up production should this be required.

 

For a number of years I have been manufacturing PCB’s at home.

Nothing complex, small voltage converters  or easy to solder projects to either teach myself how to use LED’s or sensors on technology such as Arduino.

 

Homemade Power Converter PCB

Homemade Power Converter PCB

In the past I have always started my design on graph paper, marking out where the physical components need to go and then fitting tracks to them. Which at a basic level works, and works well. You know if you have enough space, where the tracks will go and what overlaps / jumps you need where.

From graphing paper the design is transferred to a digital form and is mapped out using a graphical editor – I use Adobe Illustrator. I know its not designed for PCB layout’s but when you need something simple and quick its fits the bill perfectly!

A single sided board awaiting PCB transfer. The blue sheet is the design on 'Press n Peel' transfer sheet.

A single sided board awaiting PCB transfer. The blue sheet is the design on ‘Press n Peel’ transfer sheet.

Once I have a digital copy of the layout, I invert the image and print onto ‘Press n Peel’ toner transfer paper. Traditionally from here I have used an iron (no steam setting) to melt the toner onto the copper-board, however after speaking with plenty of people at a recent MakerFair, I purchased a laminator and haven’t looked back!

Track transfer via laminator

Track transfer via laminator

Embedding the board and template in a laminator sheet seemed to work very well to retain the heat and ensured even temperature distribution across the panel.

Single PCB and a whole sheet ready to be etched.

Single PCB and a whole sheet ready to be etched.

As you can see from above the process works exceptionally well when you need to scale up from one (single) board to a multiple set.

PCB board ready for drilling

PCB board ready for drilling

Things to note.. PCB Etchant is dangerous stuff!! Its sole purpose is to dissolve metal! There fore when your done do not tip the waste down the sink..

I’ve found that being able to produce a quick and simple circuit for a project / fix it around the house has been a great help. Granted, I’ve prob not saved money over all (after chemicals, board, laminator etc) but its great to know the things I have built are being used every day in my household.

Continuing again with my Raspberry Pi adventures and further developing my ‘BeeSafe’ project. One of the components I need to integrate is GPS module that would allow me to track the BeeHive / box should someone decide to move it.. To this end I purchased a few GPS units from ebay. This guide should get you up to speed on how to access GPS data via your Raspberry Pi / linux setup.

USB GPS with magnetic base

USB GPS with magnetic base

Plug the USB GPS into the pi, you should be able to see it detected in

sudo lsusb

Mine came up as: Bus 001 Device 004: ID 1546:01a6 U-Blox AG

Using:

dmesg | grep -i usb

I worked out that my USB GPS was paired to ttyACM0

At this point you can test your GPS device is functional and sending data by:

sudo cat /dev/ttyACM0

The next thing we need to do is pipe the GPS feed into GPSD (the gps demon) for it to interpret the data and hopefully give us something useful to use later.

sudo gpsd /dev/ttyACM0 -n -F /var/run/gpsd.sock

this command connects the output of ttyACM0 to the gpsd socket

NB: I had to ensure that the -n flag was present in this command, as trying without the flag resulted in a time out.

You should now be able to test the GPS using

cgps -s

Which will bring up a small window showing the GPS data.

Things to note; If you have any problems and cgps always displays ‘NO FIX’ under status and then aborts after a few seconds, you may need to restart the gpsd service you may have to kill and reboot the gps demon by typing

sudo killall gpsd

and then

sudo gpsd /dev/ttyACM0 -n -F /var/run/gpsd.sock

 

which will restart the gpsd service and pick up the new settings.

Now you should be able to use the GPS data for whatever your project needs; in my case I want to build a GPS fence so that if my beehive is detected leaving a known area (such as a field) then it will alert me and provide me with a GPS co-ordinate feed.

I used the Lady Ada guide on how to setup GPS devices to help me; the link is:

http://learn.adafruit.com/adafruit-ultimate-gps-on-the-raspberry-pi/setting-everything-up

Following on my project to develop a Bee monitoring tool dubbed ‘Bee Safe’.

The next part of my project is to provide the remote raspberry pi with access to the internet via a USB 3G dongle.

Fortunately in the world we live in now; finding old / used 3G dongles is very easy to do. The one I’m using was purchased from Cex for the pricey sum of £6.

£6 3G Dongle

Newly purchased 3G Dongle

While cellular data speeds and modems have vastly improved over the recent years this project only requires sending small snippets of text with the occasional photo so high speed isn’t a priority on this project.

To pair a USB dongle with a Raspberry Pi (the computer used to power Bee Safe) you need to download and install some packages; PPPD & sakis3g

To start with download PPPD via APT-GET:

sudo apt-get install ppp

Then download sakis3g:

wget "http://www.sakis3g.org/versions/latest/armv4t/sakis3g.gz"

Unpack and make the file executable:

gunzip sakis3g.gz
chmod +x sakis3g

Then execute the script which will run with a basic GUI within terminal:

sudo ./sakis3g --interactive

Sakis has a fairly comprehensive list of connections available.

Once you have been through the setup guide the modem *fingers crossed* should be online and operational. You can now exit sakis. You will stay connected.

You can check your connection and details with this command:

sudo ./sakis3g connect info

This post was pulled together from various sources, the main two being:

http://shkspr.mobi/blog/2012/07/3g-internet-on-raspberry-pi-success/

and

http://raspberry-at-home.com/installing-3g-modem/

Following on from my previous posts about a tool or piece of technology that can be used to monitor bee hives and the status of bee’s; I’m pleased to announce the next step of my development of this project.

Originally code named ‘BeePi’ because I was building on the Raspberry Pi computer system, I have developed it further and it has evolved into ‘BeeSafe’ – a micro monitoring tool used to monitor the status of a bee hive.

BeeSafe Features:

Accelerometer External Environment Sensor
Abient Temperature Sensor Magnetic Switch Alarm
Brood Temperature Sensor LED Status Lights

Which will allow me to work out:

Current temperature of Bee cluster in the Hive – Are the Bees still alive
Current temperature of the environment around the hive – Are the bee’s likely to be active
If the Hive is open – Is someone doing something to the Hive
If the hive has fallen over – Has an animal or something caused the hive to fall over exposing the inside of the hive
If the hive is being moved – Useful if you think your Hive is being stolen
Quick Traffic light: Red, Amber or Green Status of the Hive

This is the first picture of the base PCB that will operate BeeSafe:

Bee Safe Base PCB

Bee Safe Base PCB

As you can see, it still requires a lot of work including soldering all the components to the board and then programming the system to detect and report from the various sensors.

From a software perspective at the Hive level, I need to start writing how and what the software will do, how often it will record measurements, what the traffic light system will show to the users, what data will be submitted to the cloud for capture and in what frequency.

Next stop is the cloud.. While I have ideas on what data I want to capture. I need to nail down specifications on what I want the cloud to do and how I want the cloud to be engaged by users.

Web, Email, Text and API are all things I want included in the project but the balance is finding out the best way to include them. If your Hive was broken into – would you want a text message saying that? What about on-demand reporting about how your hives are doing? What about logging in to your hive in the middle of winter to confirm that the bee cluster is overwintering well and that the temperature internally isn’t dropping too low (a sign the bees are starving and dying off).

I hope to manufacture these boards in greater numbers once I have developed this initial PCB, confirming that all the components work in the way they should and that I have suitable demand for the BeeSafe Project.

 

In a previous post (http://l-k.me/J) I described an idea I had to make use of a Raspberry Pi as a local sensor tool on a bee hive, a project I’ve dubbed ‘BeePi’.

Below is a small requirement chart for the projects needs and potential:

Requirement Must Have Would Like To Have Nice To Have
Internal Hive Temp Sensor Yes
External Hive Temp Sensor Yes
XYZ Accelerometer Yes
High Capacity Battery Yes
Solar Charging Battery Charger Yes
WiFi Transmitter Yes
WiFi Hub Yes
3G Connectivity Yes
Hive Disassembly Sensor Yes
RFID Antenna Yes
Weather Station Yes

While all of these could be rolled into a singular project, but it makes sense to break up development into phases based on real world requirements and (of course) money.

A lot of what is required for this project exists in singular projects already published by the Raspberry Pi community, a large following of users are making use of the Maplin USB Weather Station (http://l-k.me/I), GPIO Temperature Sensor(s) (http://l-k.me/K) and RFiD Reader (http://l-k.me/L). The use of a 3G and / or WiFi dongle makes sending data exceptionally easy as the OS will handle any of the connecting to the internet / network leaving any software to make / receive API calls and store the data where appropriate.

The use of the BeePi as a WiFi Hub is also worth considering if you have more than one hive in a location it makes sense to have a singular hub / data collecting server that all of the other BeePi’s connect to. There are many tutorials on the internet that show you how to turn your Raspberry Pi into a WiFi hub and make use of a singular 3G dongle to connect them all to the internet (Or even host the database locally).

After a bit of juggling and budgeting my Phase One build will look like this:

Internal Hive Temp Sensor
External Hive Temp Sensor
XYZ Accelerometer
High Capacity Battery
Solar Charging Battery Charger
USB WiFi Transmitter

I don’t want to host the data from the hive locally (on the BeePi), so I will write a program to gather up the sensor data periodically and then send the data to a database hosted somewhere (more to come on that as it is developed).

I want to capture the internal brood temperature, external atmospheric temperature, XYZ geometry of the hive. The BeePi will be powered by a chunky long life battery which will be maintained by a solar panel. The hive will be connected to my WiFi network via USB WiFi stick.

To aide development and keep phases in line with each other I will design any PCB’s to include the optional bits; RFiD reader, Hive Disassembly Sensor, 3G data stick. So that should I need to add these to my project or as requirements change I don’t have to go back to square one and make a new base-board.

For the sensors I am going to be using; I’ve chosen to keep things simple:

Internal and External Temperature Sensor: DS18B20 3 Pin 1 wire temperature, these are particularly handy and cool as you can connect several to the same GPIO pin but capture data from them all separately via serial interface. The tutorial guide I am using is: (http://l-k.me/K).

XYZ Accelerometer: ADXL345 a simple I2C accelerometer which you connect  via the BeePi’s GPIO Pins (http://l-k.me/M).

Power and Solar: Power will come from a 12V 7AmpHour battery which will be charged via solar panel regulated with a solar charge controller. The board I will design will take 12V and step down to 5V which will be used to power the Raspberry Pi, WiFi and connected devices. The hope is that the battery and sun will maintain the project indefinitely however as this is all theoretical (at time of writing!) I may need A) a bigger battery B) a bigger solar panel C) BOTH.

While you can source all of these components from UK distributors, I HIGHLY recommend looking at eBay and sellers who are based on HK or china as I have found the price difference to be considerable between UK and Asian sellers.

More to come as the project develops!

*FYI this idea is still a concept and needs to be ironed out!*

It’s worth mentioning one of the great technology releases of 2011 / 2012 was the Raspberry PI (www.raspberrypi.org), a credit card sized computer powered by an ARM processor which can run a select few flavours of Linux.

One of the great selling points of the Pi, are it’s GPIO Pins (General Input Output Pins) which allows you to connect up a vast multitude of sensors, lights, relays directly to the Pi and engage with it via the command line or computer program.

As an avid bee keeper I have spent my last few summers tending to a few bee hives, growing up two colonies to hopefully gather up lots of honey for me! (a treat I love!).

At a recent bee keeping event I ran into a man who had developed a bee hive sensor that is able to be placed inside the bee hive to capture a number of different aspects of a bee hive, such as; temperature, hive geometry to name a few. It was a great product but A) well out of my price range and B) not flexible enough to further development.

So I thought to myself, could I make something similar and what would it look like. Well the short answer is yes, and below are the (incomplete) specifications for what I would want my ‘BeePi” to look like and operate.

Project BeePi; An autonomous data gathering tool use to sense, collect and report back on a bee hive and hive surroundings.

It will feature;

Sensors:Hive internal temperature sensor, external temperature sensor, XYZ accelerometer and hive disassembly removal sensor.

Communications: The BeePi can connect via Wifi to a hub, Wifi to a master BeePi (collecting data from a whole apiary) or communicate via a 3G/4G dongle. Potential exists for a RFID based  ‘Check-In & Check-Out’ style system – useful if many people manage the hives in a particular area.

What will these sensors do?

Well, imagine your bee-hive(s) is located in an area where you suspect animals (or people) could knock the bee hive over. Using the accelerometer when the box is turned at an angle (for example being knocked over) the BeePi could send a message (via sms, pre-recorded message or email) with details about the hive, its location and at what time the event occurred.

Using an internal temperature sensor placed close to the cluster of the hive in the brood box it will give you an indication on the current status of your bees, including if the queen is laying and overall health of the hive. Typically happy brood = happy hive.

An external sensor placed close to the enterence the hive will give you an indication on if the bees are flying, as generally lower than 13 – 10c and they will stay inside and keep warm.

Hive disassembly sensor will alert you to when your hive is being dissembled, this could be handy if you believe someone is stealing from your hive and you wish to track times and events.

I believe that this is a valuable idea and project and will document my progress as I develop it further.

 

With the free time from the bank holiday, not wanting to spend the whole weekend inside I decide to devote sometime to my BioGas project. Having considered the last run a success, apart from producing a lot of smoke the gas produced did eventually light, leading me to believe that the reactor was working and just needed to continue to warm up to operating temperature.

 I loaded the base full of charcol and get started again. Within minutes the base was hot and I loaded the chamber with wood pellets – sealing the top.

After 5 minutes the colour and quantity of the smoke changed and I used my blow torch to ignite the smoke.  Instantly I was presented with a hot yellow flame, while the flame was not able to maintain itself I believe this is due to the water content and lack of mixed air – a problem soon to be fixed.

Below is a ‘basic’ drawing of the setup

I have installed flare stacks at all the post-process points so that I can check the output of the gas – The last thing I want to do is do all this work and end up with something that doesnt ignite!

So project one complete, I can successfully make flamable gas from waste wood! Next step – Clean, Condense and find a use for the wood gas.

*UPDATE 14th October 2012*

Having now purchased my own air compressor (yay!) I was able to fire up the reactor again and do an extended test. Below is a snippit of video I was able to record:

Wood Gas Reactor

Project 2: Cleaning & Condensing

Fresh from the reactor the gas is still very hot and contains dissolved in the smoke a number of unhelpful substances – water being the biggest. In its highly energised state the gas moclules lack density and compressing them would be very difficult.

From my research I have found several methods of cooling hot gas (the top 2 being):

  • Heat Exchanger / Radiator
  • Water bubble tank

To keep things simple I opted to use a sealed water bubble tank. This is where the end of the outlet from the reactor is fed under water and the gasses are bubbled up through the water, both cooling the gas and seperating the water / water soluable substances at the same time. Keeping the water as cold as possible will hopfully force more of the waste componensts to seperate from the flamable gas cloud.

If needed a further process using hay as a filter medium can be slotted into place to absorb waste if needed – however I do not think this well be required if the ice water filter goes to plan.

 So as part of my renewal projects and drive I have been focused and interested in Biogas, in particular gas produced from the breakdown of wood at high temperature with limited oxygen.

After my experiments and success with making a biodiesel reactor and running a car off biodiesel for many years I had felt that this project fitted the natural progression. If I could make a fuel for diesel engines making a fuel for spark based engines was the alternative.

Before starting on this project I did a lot of research online.

YouTube was a fantastic resource that allowed me to see other peoples success but also how their projects have come together and the pitfalls they encountered.

BBC’s Bang goes the theory did an experiment where they used coffee grounds in a similar fashion, the link can be found here.

Another site I made extensive use of was MD Pub’s Gasifier, his research, experiments and documentation became the grounds for my own jumping off points.

So what is a Gasifier?

A Gasifier is a combustion chamber where organic substances (wood, coffee grounds or other organic substances) are burnt at high temperature with limited oxygen, this causes the organic and volatile compounds to separate. In principle it goes like this:

Wood + Limited Oxygen = Carbon Dioxide + Carbon Monoxide + Carbon + Water + Hydrocarbons + Heat

The wood (or organic substance) becomes unstable and breaks down into less complex substances – otherwise known as Pyrolysis (Wikipedia Link).

Once this process has happened the gas is in a raw and almost ‘dirty’ state, at such a high temperature it contains moisture and tars that were not thermally broken down, before it can be used in any combustion engine the gas must be cleaned and impurities removed.

I have broken my project up in to two sections.

  1. Gas production device
  2. Gas cleaning device

This post focuses on Part 1, the manufacture of a BioGas production system.

From the research I did, it seems the most successful projects were ones that used compressed air, injected into the combustion chamber at the hottest point. I chose to make a ‘injection ring’ where 5 copper pipes inject air into a steel cylinder. To get started I needed a base:

Using an old 25 litre chemical drum, I cut the top off, leaving the pressed steel rim intact, This gave me a large working area to easily fit parts and get my hands into areas needed for screwing / working. For my combustion chamber I found compliments of eBay an old fire extinguisher – yes I’m aware of the irony.

I cut the base off the extinguisher:

and removed the razor sharp edge left by the cutting tool:

You can see from the positioning the plan, filling the now top of the chamber with the reaction occurring at the neck with the gas and ash flowing out of the bottom.

The next step was to drill holes and fit the air injection pipes. The drilling of the holes and fitting of the pipes was very simple, with a small jig setup to prevent the drill from travelling on a circular edge. Once I had the pipes fitted I made a ring of copper pipe around the outside and connected all the injection tubes to the ring. This gave me a single point where I could connect an air hose and apply compressed air.

From some of the learning’s from MD Pub’s pages, he had major trouble with gas tar and water escaping from the gaps between the pipe and the cylinder. So I decided before moving on that I would seal the pipes to the cylinder. My original idea was to weld or braze the gap, but after watching numerous videos on how to braze and following the pack instructions to the letter, I was unable to form a solid bond that couldn’t be chipped off with a finger nail – see photo

So my next idea was to use chemical metal. A two part compound that when combined becomes tough and bonds metal together. Fab I thought. After cleaning the remains of brazing rods off the copper and steel I set about trying to glue the gaps up. What a success! The glue set, didn’t shrink and all the gaps were filled. All my problems were solved – or so I thought!

I left the project for a week or so, coming back everything looked good, the glue hadn’t fallen off and holding the base up to the light resulted in no pin pricks of light shining through. Then I dropped it (the fire extinguisher) and the glue shattered. Being so brittle and so inflexible all of the joints immediately failed I needed a better idea, a more flexible idea.. Re-reading MD Pub’s pages he talked about using a flexible high temperature silicon sealer to fill in all the gaps. So a quick trip down the local hardware store saw me back in business.

After sealing all the gaps and joints I moved onto making a lid, making friends with a local metal workshop I had a rummage around the offcuts bin and found a sheet of metal that would be perfect. Cutting a doughnut shaped ring out from the metal and fitting it too the inverted fire extinguisher with a little silicone seal in place around the gaps:

Fab! So now I have fitted my chamber up, secured a constant stream of compressed air for the reaction to occur. All that was next was to test my Gasifier.

Loading up my reaction chamber with wood and charcoal I sealed the chamber (with the now lid, ex base of the fire extinguisher). Once the airline was attached and a constant stream of air was being forced into the chamber I felt the Gasifier immediately heat up, plenty of smoke was being product from the exit port but nothing flammable. This went on for 20 minutes and as the temperature increased so did the quantity of non-flammable gas being produced. Sadly the seal of the combustion chamber failed soon after, resulting in a small fireball about the size of a football coming out from the combustion chamber. This has shown me two things, One: Gas was being produced, Two: I need a better seal on my gas chamber.

My plan for the rest of this project is to find / design a better heat proof seal for the combustion chamber and to replicate the experiment. I believe I’m on the cusp of making this project work, so a few more steps particularly in the name of safety shouldn’t be a problem.