Quick Tip: Making Momentary Buttons Breadboard Friendly

Momentary buttons are probably one of the most common components in most projects.  Unfortunately, most buttons are not made to be inserted into a breadboard.  Most do line up and some will work if you are very nice to them.  However, the pins are normally curved and very short so their ability to connect with the breadboard is very marginal and can lead to problems that may at first seem like issues with your microcontroller or the button itself.  More than likely the issue is really just that the button isn’t making good contact with the circuit.

To eliminate this problem from my projects, I use the following process to make the buttons breadboard friendly.  I recommend keeping a set of these specifically for breadboarding to save you time down the road.  However, if you need to you can certainly reverse these modification later to use the buttons in your final product.

Basically, what I do is attach extensions to the “pins” coming from the button so that they fit tighter and deeper into the breadboard.  This is certainly not an original idea.  Many before me have done the same.  However, since I was making up several of these recently I decided it would be good to document and reference later for others getting started in electronics.

I start by getting a piece of male pin headers – one for each pin on the button.  Hold the plastic housing with your fingers or a pair of pliers and then using some needle nose pliers, pull the pins out of the plastic.  These pins are much more rigid than just wire and are easier to insert into the breadboard without worrying about them bending.
Once you have the pins out, find the holes on a spare breadboard that align with the pins of your button and insert the new header pins into these holes.  Only push them in far enough that they are secure and try to make sure they are all sticking up the same height.  We use this technique to ensure that when we solder the pins to our button that they will line up perfectly with the breadboard.

Next, we will place the button on top of the standing pins and align it so that the buttons pins are on the outside of the new pins.  We’ll next add some alligator clips to hold the two parts together to be soldered.  So, don’t be overly concerned about getting everything perfect at this point.  You may need to bend the pins on the button out just slightly to make them easily fit on the outside of all the new pins.

Using the alligator clips, secure one corner on properly.  Make sure that the new pin extends as high up on the button’s pin as possible so that we get good contact at least on the top & bottom of the button pin.  If there is a curve or loop in the button pin, don’t worry about trying to straighten it.  It will not be a problem.  That gap will easily fill in with solder.  Once you get one of the clips on then do the opposite corner and then the other two pins.

Now that you have everything secure, it’s a simple process of soldering all the pins together.  You may accidentally solder your clips to the pins.  This is not a problem.  A simple touch of the soldering iron will cause it to release without undoing the main solder joint if done quickly.  Be careful, the clips can get hot quickly in this process.

Now you have a button perfect for use in a breadboard that you can depend on to give you a good connection to the rest of your circuit and loosen with use. 

This same technique can be applied to many types of components with similar types of connectors that are not necessarily breadboard friendly. 
Enjoy and please share your projects or suggestions in the comments!

Making a Gadgeteer DaisyLink Extender Module

I’ve been working on designing a .NET Gadgeteer DaisyLink module for a project I’m working on and ran into a limitation of the GHI Extender module that I thought warranted an improvement (aka “hack”).  I’ll detail the steps I took to convert a GHI Extender module into a DaisyLink Extender module in this post.

In case you’re unaware of what DaisyLink is…in a nutshell, it’s a way to chain together Gadgeteer modules so that you only have to use a single socket.  An example of such a module is the GHI Smart Multicolor LED module.  On a DaisyLink module there are two sockets – the upstream socket (the one going toward the mainboard) and the downstream socket (the one going away from the mainboard). 

The communication for DaisyLink happens using the I2C protocol and a neighborhood bus.  It isn’t the intent of this post to explain in detail how DaisyLink works.  For that info, see the .NET Gadgeteer Module Builders Guide.  However, I mention this because the neighborhood bus is the reason for this hack.  All the pins in the two sockets on a DaisyLink module can be passed straight through from one socket to the next except the neighborhood bus (socket pin #3).  This pin has to be activated/deactivated independently as this is the mechanism that the mainboard uses to identify which module it is communicating.

The GHI Extender module is in my opinion the most useful of all Gadgeteer modules since you can basically do anything with it.  Before I started understanding how DaisyLink worked, I always assumed that the Extender module had two sockets on it so that it could be used to develop DaisyLink applications since I otherwise see no application for the other socket except as a way to tie two cables together.  The pins on the two sockets are directly connected together and to a header on the edge of the module.  As I mentioned above, this is a problem since I need to be able to control the value of pin #3 independently on each socket.  So, it’s time to pull out the soldering iron!

If you flip the Extender module over and rub the solder mask a little to polish it, you will see the circuits.  I’ve highlighted in green the circuit for pin #3 that goes to both sockets and to the header pad.  Note that the left-most junction is where the circuit connects to what we will refer to from now on as the downstream socket.  We’re going to add an additional pin to the header called “P3*” (since * is used by Gadgeteer to denote downstream sockets) and make the header labeled “P3” only connect to the upstream socket pin #3.

 

We’ll begin by using a box cutter or Xacto knife to scrape the solder mask off the circuit on both sides of the junction we want to bypass.

 

 

 

Next, we’ll use the box cutter to make four deep cuts through the copper circuit we just exposed and then we will remove the sections.  The cuts to make are shown in red on the picture to the right.  Remove all the copper between each set of parallel cuts.

 

Now that pin #3 of the downstream socket has been isolated, we need to connect the two circuits that we just cut back together so that the upstream socket pin #3 will be connected to the “P3” header.  Start by using the box cutter to scrape a little more of the solder mask off the copper on the right side of the top circuit we cut and below the bottom circuit we cut.  Now, take a thin wire and solder it to the two pieces of exposed copper.  If you have some Kapton tape to stick down the wire while soldering, it will make it a lot easier.  However, you can manage it w/o if necessary.  It also helps if you tin the wire with some solder before attempting to connect it to the PCB.  You will probably not get a large bead of solder to stick to the tiny piece of copper.  As long as you get enough so that the wire is secured that will be sufficient.

We’re done on the back side of the PCB.  Next we’ll attach the male headers to the board.  Although the module has 10 header holes, we will need a section of header that has 11 male pins.  To make it easier to solder every square, put the header into a spare breadboard and put the Extender module on top.  I also like to put an extra piece of header underneath the module on the other side to give it some support and help ensure it stays flat.

Take a small piece of thin insulated wire and strip a very small amount off one end and tin it with some solder.  We’ll solder this to pin #3 of our downstream socket.  Note that in the picture on the right, pin #1 is in the bottom left corner of the socket.  All the even numbered pins are in the top row and the odd numbered pins are on the bottom row.  So, pin #3 will be the second pin on the bottom row.  It will greatly simplify soldering if you have a tiny alligator clamp that you can clamp the wire to the PCB so that the exposed end of the wire is lying on top of the pad for pin #3 as is shown in the picture.  If you have a flux pen, it would be a good idea to add a little flux to the SMD connectors before soldering.  However, if you take care and get it done in one heating you should have no problems w/o additional flux.  Use your soldering iron to heat the wire and pad so that the reflowed solder connects the two together.  You may need to add a tiny amount of additional solder.  Just be careful not to bridge any of the other pads.  Solder the other end of the wire to the extra header pin.

Let it cool a few seconds and then you can remove it from the breadboard.  Take caution when removing it as the extra header pin could easily snap off if torqued side-to-side.

Finally, to help protect the uninsulated wire we added to the bottom side of the board I created a label in Excel and printed and taped it to the underside of the board to help label the extra header in case some day years from now I forget why it’s there.

Now that I have a good way to prototype, it’s time to go finish my new DaisyLink module!  Thanks for stopping by.

Merry Christmas!

Operation: Organize My Parts (OOP)

This is a series of posts I’m doing as I go from working out of a collection of unorganized boxes and bags to something more productive and efficient using Plano 3449 boxes.

	Resistor Storage
	Electrolytic Capacitor Storage

The Excel spreadsheet that contains all of my envelopes and labels can be downloaded here.

OOP – Electrolytic Capacitor Storage

Tonight I decided to take on the next chapter in “Operation: Organize my Parts!” (OOP).  Since I didn’t want to start a very large project, I decided to move my electrolytic capacitors into some Plano 3449 boxes.  I’ve been using the little Ziploc bags that they came in when I bought them and that’s not such a bad solution.  However, I had all of the little bags of caps crammed into one larger Ziploc bag and that was inconvenient to have to pull them all out and sort through them every time I needed one.

Since electrolytic capacitors are considerably larger than resistors, the envelope method I used to organize my resistors wasn’t practical.  So, I decided that I’d give each capacitor value it’s own compartment in the Plano box.  Currently, I only keep 10 different values so this isn’t bad since it will only require two boxes to store them all.

To label the compartments to make the values easy to identify, I added a new worksheet to the Plano 3449 – Electronic Organization file.  I created a page of labels that can be used to print something similar to the envelopes used before except that for these the paper is folded and taped so that one of the labels is visible from the bottom of the box and one is visible when the box is open.  This makes it very easy to find the right box and to identify the parts when the box is open.

This solution has worked very well and will save me a lot of time in the future that would have been spent rummaging through Ziploc bags.  If you want to use this solution, download the Excel file and use the “Electrolytic Capacitor Labels” worksheet.  I hope this solution helps someone else as much as it has me.

View from the bottom of the Plano box.	View from inside the Plano box.

OOP – Resistor Storage

I finally did it.  I threw in the towel.  I finally reached the point where my loss of productivity forced me to stop and do something I’ve been threatening to do for a while.  I decided to get organized.  I’ve spent a lot of time out in the wood shop this year getting it organized (more posts coming!). However, the electronics lab is a different monster that I’ve been thinking about for years about how to best handle but could just never come up with that perfect unique idea.  Operation: Organize my Parts (OOP) has begun.

So, I decided to think smaller.  I’ve been spending a lot of time working on several different electronics projects in recent months and by far the most time consuming activity has been searching through my pile of resistors.

 

In truth, I started this little project over two years ago when I bought a lot of fourty Plano 3449 mini tackle boxes off eBay (for about $1 each) for this purpose.  However, I took a couple years off from doing anything serious with electronics and so the boxes have just sat in a bigger box in my office.  When I bought the boxes, my idea was basically to put every different value in a separate compartment.  However, the more I thought about it that was a terribly ineffective use of space since a vast majority of the resistor values I have come from assortment bags and I only have 5 to 10 units of each value.

So, I started to think about how to better utilize the space within the compartments of the Plano boxes to help reduce the number of boxes required to store the complete resistor collection and to allow me to be able to quickly and easily find & store resistors when needed.  To make it easy to find resistors, I knew I needed them labeled with their numeric value and sorted.  To make it easy to store resistors, I knew I would need their color codes easily viewable.

The solution I finally arrived up was an envelope system that had a closing flap that contained the resistor value and the color codes such as the one on the left.  The colored flap secures the envelope and also prevents accidental spilling should the box get dumped.  To make the envelopes, I decided to create an Excel spreadsheet to help with the color coding.  This turned out to be a much bigger challenge than I initially expected.  Consider this my Christmas present to you should you decide to use it (I’ll expect a Christmas card in return! ;)

After printing out pages of all the envelope templates that I needed, it was then just a matter of sitting in front of the TV with some scissors cutting out all the squares, folding them and taping the ends.  I then sorted through and identified all the resistors and placed them in their appropriate envelopes.

The rule of thumb that I've been using and which has worked very well regarding resistor inventory is to start out with a couple 1000 resistor assortments from eBay.  Then as I run out of a particular value, I order 200 to replace it.  20 resistors is about all that will comfortable fit in the tiny envelopes.  So, for more than that for a single value they get their own dedicated compartment within the box.  I place the envelope over the divider so that it's value & color code are easily visible.

I'm now able to fit all of my resistors into three of the Plano boxes and can locate the needed one within seconds instead of minutes.  It's especially nice that the boxes are clear and I'm able to view the labels through the box lid without opening it to locate the correct box.  It took several nights to get it all setup and sorted but now it's very easy to maintain and I consider it well worth the effort.

A couple of issues to mention concerning the Excel spreadsheet.  First, I was focused on the majority of my resistors that are 1/4W and failed to provide a way to note this on the envelope.  Since I'm not willing to recreate the envelopes just to add a "1/4W" label on them, the approach I'm taking is that as I add resistors of a different Watt rating then I hand write "1/4W" below the resistor value in the empty white space and print the new envelope for the new value with the Watt value on it.  If you decide to use my spreadsheet, you should add the W label on there before printing.  Secondly, the data formatting abilities in Excel seems to have a limitation where it is not possible to have it hide the decimal if the format contains the ability to have decimal places.  For example, if the format is "0.##" and the number is 10 then it will display the number as "10." (including the period).  So, for this reason you will see a lot of extra periods on the envelopes.  If you know a way to eliminate the period, please leave a comment with the solution and I'll update the spreadsheet.

I hope this post has helped someone else escape "resistor hell".  Now onto capacitors...

FEZ Hydra Announced!

Today, GHI Electronics announced their much anticipated FEZ Hydra Gadgeteer mainboard.  This is GHI's first Open Hardware/Software Gadgeteer board.  The Hydra represents a significant upgrade in power vs. the FEZ Spider Gadgeteer mainboard released earlier this year and is being offered at a lower price.  I'll briefly compare these two Gadgeteer boards here and will be presenting a more exhaustive look at the Hydra in a few days when my board arrives and I can do an unboxing post.

See GHI's official announcement.

	FEZ Hydra	FEZ Spider
Processor	240MHz 32-bit ARM9 (running at 200MHz)	72MHz 32-bit ARM7
RAM	16MB SDRAM	16MB SDRAM
Gadgeteer Sockets	14	14
Type A	2	2
Type B	1	1
Type C	0	1
Type D	1	1
Type E	0	1
Type F	1	1
Type G	1	1
Type H	0	1
Type I	2	4
Type K	1	1
Type P	1	2
Type R	1	1
Type S	2	2
Type T	1	1
Type U	4	4
Type X	2	2
Type Y	10	7
Type Z	1	1
FLASH	4 MB	4.5 MB
Open Source Hardware	Yes	No
Open Source Software	Yes	No
Graphics Support	Yes	Yes
TFT Display Interface	Yes	Yes
FAT Support	16/32	16/32
TCP/IP Stack	SSL, HTTP, TCP, UDP, DHCP	SSL, HTTP, TCP, UDP, DHCP
USB Device	USB 2.0 (12 Mbps *)	USB 2.0 (12 Mbps)
USB Host	No	Yes
SD Card Support	4-bit w/ no size limit	4-bit w/ no size limit
Dimensions	W 3.42" x L 2.44" x H 0.5"	W 2.25" x L 2.05" x H 0.5"
Active Power Consumption	130 mA	160 mA
Idle Power Consumption	TBD	120 mA
Hibernate Power Consumption	TBD	40 mA
Operating Temp	-20 to 70C	-20 to 70C
RoHS Compliant	Yes	Yes
Lead-free Compliant	Yes	Yes
Configurable LED	1	1
Price	$79.95	$119.95

*USB Device was previously reported to have 480Mbps speed. Prior to shipping this was changed.