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If you need a truly random event generator, just wait till your next rainstorm. Whether any given spot on the ground is hit by a drop at a particular time is anyone’s guess, and such randomness is key to this simple rig that estimates the value of pi using raindrop sensors.

You may recall [AlphaPhoenix]’s recent electroshock Settlers of Catan expeditor. The idea with this less shocking build is to estimate the value of pi using the ratio of the area of a square sensor to a circular one. Simple piezo transducers serve as impact sensors that feed an Arduino and count the relative number of raindrops hitting the sensors. In the first video below, we see that as more data accumulates, the Arduino’s estimate of pi eventually converges on the well-known 3.14159 value. The second video has details of the math behind the method, plus a discussion of the real-world problems that cropped up during testing — turns out that waterproofing and grounding were both key to noise-free data from the sensor pads.

In the end, [AlphaPhoenix] isn’t proving anything new, but we like the method here and can see applications for it. What about using such sensors to detect individual popcorn kernels popping to demonstrate the Gaussian distribution? We also can’t help but think of other ways to measure raindrops; how about strain gauges that weigh the rainwater as it accumulates differentially in square and circular containers? Share your ideas in the comments below.

[via r/electronics]


Filed under: Arduino Hacks, misc hacks
Ago
16

Rapid stripboard prototyping made easy with Lochmaster

4.0, abacom, Design, lochmaster, oscillator, review, Software, software review, square, stripboard, tronixstuff, tutorial, veroboard, wave Commenti disabilitati su Rapid stripboard prototyping made easy with Lochmaster 

Introduction

As a beginner in the world of electronics, sooner or later you’ll want to make a more permanent project than what can be constructed on the solderless breadboard. It’s easy to say “make your own PCBs” – however this can introduce a steep learning curve, not to mention the cost and time involved in waiting for PCBs to arrive – and hoping they’re correct. Thus for many people a happy medium is transferring prototype circuits over to stripboard – it’s really cheap (check ebay), you can keep various sizes on hand, and it’s quick.

However planning more complex circuits can be difficult – so it would be much easier with the use of a software design tool. Which brings us to the subject of our review – the Lochmaster v4.0 software from Abacom. It’s an incredibly easy to use developer’s tool for strip board projects. No more loose pieces of graph paper, soldering parts “one row too far over”, or lost design plans – you can now design stripboard projects efficiently and with ease.

Installation

Available for all versions of Windows from XP to 8, Lochmaster is less than ten megabytes and is distributed electronically after purchase – so backup your installation file when received. Otherwise it’s a quick install, you don’t need any extra framework software and due to the size will run well on less-specified machines. Although we have screen shots in the review below, you can download a trial version - so it won’t cost you anything to check it out yourself.

Designing your circuits

Once installed, opening Lochmaster for the first time you’re presented with a blank example of stripboard ready for your components:

Lochmaster

However you can also use different types of prototyping board, such as varieties with all holes, edge connectors, mounting holes, different copper directions – or even make your own board to match a preferred style. Boar dimensions can be displayed in measurement units as well as “holes”. Then it’s a simple matter of selecting a part library from the drop-down list on the left of the window. For example, to add a 555 timer (which is an 8-pin DIL part) select the “ICs” library, click on the 8-pin enclosure and the following window appears, prompting you to fill out the appropriate details such as label, type etc:

Lochmaster 555

… then you can drop the 555 on the board. It then becomes an object which can be dragged around and placed where you need it. You can also create and modify the component libraries, and also create your own custom parts.

At that point, you might want to cut the tracks on the other side of the board. By clicking the “turn around” button the menu bar, you’re presented with the bottom of the board. Using the “add/split” button on the vertical toolbar between the library and the board, you can then virtually cut the tracks, for example:

lochmaster

You can also see the rounded circles which represent solder joints. After a few minutes we found dragging and dropping components onto the board very simple, and with the turn-around button you can easily flip sides until the placement looks good. After placing components, running the necessary links or wires is simple with the “draw jumper wire” tool. They can run in any direction, and also have corners, for example:

Lochmaster wires

You can also adjust the colours and thickness of the wires,  and of course can also be placed on the other side of the board – just flip it around and place the wires. After wiring things up and getting to the stage when you’re ready to build – you can test the connections to ensure you haven’t mis-counted holes or tracks. Using the “Test mode” tool you can click on tracks and the sections that are electrically connected to the point with the cursor are all highlighted – for example if you click on the point marked by the black arrow below, the connected tracks are highlighted:

lochmaster test

If you don’t like the 3D-rendered components, you can also work with normal 2D in colour or black and white:

lochmaster 2D

For final quality-control, you can also review the project at any time with “X-ray” view, which shows an outline of the parts on the other side, for example when looking at the bottom of the board, turning on X-ray results with:

Lochmaster xray

You can also generate component lists, which are great for documentation or simply making up a shopping list. It can be exported to .xls or text file, for example:

lochmaster list

And then you can export your project as an image (.jpg or .bmp), HPGL machine file – and print out both sides to serve as an assembly guide. There is also standalone file-viewer software, so you can share your designs with others who haven’t got the full Lochmaster software installed.

Example project

After experimenting with Lochmaster for a short while, we decided to test using it with a real project that a beginner might assemble. For example, a square wave oscillator from an old Talking Electronics magazine (click image for larger version):

square wave oscillator

Nothing too complex, but a useful tool for anyone experimenting with electronics. It’s a 555 astable with six different RC values which allows you to select from 1, 10, 100, 1 k, 10 k and 100 kHz outputs. The first step is to gather all the components together, so you know the widths and number of holes each needs on the stripboard:

lochmaster_components

The next step is to measure the board, as you can enter the dimensions via Board>Edit board layout… into Lochmaster to avoid having excess space in the design plan. Then after consulting the schematic and the single-layer PCB layout from the magazine, it’s a simple matter of placing the parts onto the virtual board after checking how the fit in on the real thing:

osciillator top

… and the flip-side:

oscillator bottom

Not a work of art – but it works.  (We didn’t fit the 100 kHz setting, as the capacitor wasn’t in stock). And that’s the neat thing – you can experiment with placement until you’re happy, then double-check connections before soldering. You might find even after some planning, that you may deviate from the plan. Fair enough, but just double-check what you’re doing. And a short while later, the results, top and bottom:

oscillator PCB top

oscillator PCB bottom

Conclusion

If you’re a beginner and don’t have the time, money and patience to design your own PCBs – Lochmaster is ideal. It’s a neater way to visualise physical circuits, as well as filing and sharing them with others.   To order your own copy, get the trial version, or if you have any questions please contact Abacom. Full-sized images of the screen-shots can be found on flickr. And if you made it this far – check out my new book “Arduino Workshop” from No Starch Press.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

[Note - Lochmaster software license was a promotional consideration from Abacom]

The post Rapid stripboard prototyping made easy with Lochmaster appeared first on tronixstuff.

Introduction

There has been a lot of talk lately about inexpensive DDS (direct digital synthesis) function generators, and I always enjoy a kit – so it was time to check out the subject of this review. It’s the “FG085 miniDDS function generator” from JYE Tech. JYE is a small company in China that makes inexpensive test equipment kits, for example their capacitance meter (my first kit review!) and DSO. The capacitance meter was good, the DSO not so good – so let’s hope this is better than their last efforts.

Assembly

The instructions (AssemblyGuide_085G) are much better than previous efforts, and if you have bought the kit – read them. The kit arrives in a large zip-lock bag, with the following bundle of parts:

The AC adaptor is 100~240V in, 15V DC out. Everything is included with the kit including a short BNC to alligator clips lead for output. The PCBs are very good, with a nice solder mask and silk screen:

and back:

At this point we realise that most of the work is already done. There’s two microcontrollers ATmega48 and ATmega168- one for display and user-interface control, and the other for function generation. It takes only a few minutes to solder in the through-hole parts, headers and sockets:

… then you flip over the PCB and add the LCD:

… followed by the buttons and rotary encoder. From previous research this is the part that causes people a lot of trouble – so read carefully. There’s a lot of buttons – and if they aren’t inserted into the PCB correctly your life will become very difficult. The buttons must be inserted a certain way – they’re “polarised” – for example:

As you can see above, one side has a double-vertical line and the other side has a single. When you fit the buttons to the PCB – the side with the double-vertical must face the left-hand side of the PCB – the side with the DC socket. For example:

Furthermore, don’t be in a rush and put all the buttons in then try to solder them all at once.  Do them one at a time, and hold them tight to the PCB with some blu-tac or similar. If they don’t sit flush with the PCB the front panel won’t fit properly and the buttons will stick when in use. So exercise some patience, and you’ll be rewarded with an easy to use function generator. Rush them in and you’ll be very unhappy. I warned you! After fitting each button, test fit the front panel to check the alignment, for example:

Then you end up with nicely-aligned buttons:

… which all operate smoothly when the panel is fitted:

After the buttons comes the rotary encoder. Be very careful when fitting it to the PCB – the data legs are really weak, and bend without much effort. If you push in the encoder, be mindful of the legs not going through the holes and bending upwards. Furthermore, when soldering in the encoder note that you’re really close to an electrolytic – you don’t want to stab it with a hot iron:

The CP2012 chip in the image above is for the USB interface. More on that later. Now the next stage is the power-test. Connect DC power and turn it on – you should be greeted by a short copyright message followed by the operation display:

If you didn’t – remove the power and check your soldering –  including the capacitor polarities and look for bridges, especially around the USB socket. Now it’s time to fit the output BNC socket. For some reason only known to the designers, they have this poking out the front of the panel for the kit – however previous revisions have used a simple side-entry socket. Thus you need to do some modifications to the supplied socket. First, chop the tag from the sprocket washer:

… then remove the paper from the front panel:

Now solder a link to the washer in a vertical position:

… then fit the BNC socket to the panel, with the washer aligned as such:

Finally, align the top panel with the PCB so the BNC socket pin and washer link drop into the PCB and solder them in:

If you want to use the servo mode, solder three short wires that can attach to a servo form the three “output” pads between the BNC and USB socket.

Finally, screw in the panels and you’re finished!

Using the function generator

Operation is quite simple, and your first reference should be the manual (manual.pdf). The display defaults to normal function generator mode at power-up – where you can adjust the frequency, offset, amplitude and type of output – sine, square, triangle, ramp up, ramp down, staircase up and down:

The ranges for all functions is 0~10 khz, except for sine which can hit 200 kHz. You can enter higher frequencies, such as up to 250 kHz for sine – but the results aren’t so good.

Instead of filling this review with lots of screen dumps from an oscilloscope to demonstrate the output – I’ve made the following video where you can see various functions being displayed on a DSO:

You can also create signals to test servos, with adjustable pulse-width, amplitude and cycle times. However you’ll need to solder three wires onto the PCB (next to the BNC socket area) to attach to the servo.

According to the user manual and various retailers’ websites – the FG085 can generate frequency sweeping signals. These are signals that sweep from a start to as finish frequency over a period of time. However the firmware on the supplied unit is old and needs updating to enable this function. You can download the firmware in .hex file format from here. Then go and dig up an AVR programmer and avrdudeAt the time of writing we had some issues with the signature not being recognised when updating the firmware, and solidly bricked the FG085. Our fault – so when that’s sorted out we’ll update the review – stay tuned.

There is also a USB port on the side – after installing CP2102 drivers in Windows we could connect at 115200 bps with terminal, however all the FG085 returned was the firmware version number. Perhaps later on the designers will update the firmware to allow for PC control. Somehow I wouldn’t bank on it.

Oh – if you’re wondering what DDS is - click here!

Conclusion

It’s an interesting piece of equipment. Putting the firmware upgrade issues to one side, the FG085 does what it sets out to do. During testing it worked well, and we didn’t come across any obvious inaccuracies during use.  The price varies between US$43 and $50 – so for that money it’s  a good kit. Just take care during construction and you’ll be fine.

The function generator is available in kit form or assembled, with or without panels from China. The kit version with panels is also available from Sparkfun (KIT-11394) and their resellers. Full-sized images available on flickr. This kit was purchased and reviewed without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.


Introduction

There has been a lot of talk lately about inexpensive DDS (direct digital synthesis) function generators, and I always enjoy a kit – so it was time to check out the subject of this review. It’s the “FG085 miniDDS function generator” from JYE Tech. JYE is a small company in China that makes inexpensive test equipment kits, for example their capacitance meter (my first kit review!) and DSO. The capacitance meter was good, the DSO not so good – so let’s hope this is better than their last efforts.

Assembly

The instructions (AssemblyGuide_085G) are much better than previous efforts, and if you have bought the kit – read them. The kit arrives in a large zip-lock bag, with the following bundle of parts:

The AC adaptor is 100~240V in, 15V DC out. Everything is included with the kit including a short BNC to alligator clips lead for output. The PCBs are very good, with a nice solder mask and silk screen:

and back:

At this point we realise that most of the work is already done. There’s two microcontrollers ATmega48 and ATmega168- one for display and user-interface control, and the other for function generation. It takes only a few minutes to solder in the through-hole parts, headers and sockets:

… then you flip over the PCB and add the LCD:

… followed by the buttons and rotary encoder. From previous research this is the part that causes people a lot of trouble – so read carefully. There’s a lot of buttons – and if they aren’t inserted into the PCB correctly your life will become very difficult. The buttons must be inserted a certain way – they’re “polarised” – for example:

As you can see above, one side has a double-vertical line and the other side has a single. When you fit the buttons to the PCB – the side with the double-vertical must face the left-hand side of the PCB – the side with the DC socket. For example:

Furthermore, don’t be in a rush and put all the buttons in then try to solder them all at once.  Do them one at a time, and hold them tight to the PCB with some blu-tac or similar. If they don’t sit flush with the PCB the front panel won’t fit properly and the buttons will stick when in use. So exercise some patience, and you’ll be rewarded with an easy to use function generator. Rush them in and you’ll be very unhappy. I warned you! After fitting each button, test fit the front panel to check the alignment, for example:

Then you end up with nicely-aligned buttons:

… which all operate smoothly when the panel is fitted:

After the buttons comes the rotary encoder. Be very careful when fitting it to the PCB – the data legs are really weak, and bend without much effort. If you push in the encoder, be mindful of the legs not going through the holes and bending upwards. Furthermore, when soldering in the encoder note that you’re really close to an electrolytic – you don’t want to stab it with a hot iron:

The CP2012 chip in the image above is for the USB interface. More on that later. Now the next stage is the power-test. Connect DC power and turn it on – you should be greeted by a short copyright message followed by the operation display:

If you didn’t – remove the power and check your soldering –  including the capacitor polarities and look for bridges, especially around the USB socket. Now it’s time to fit the output BNC socket. For some reason only known to the designers, they have this poking out the front of the panel for the kit – however previous revisions have used a simple side-entry socket. Thus you need to do some modifications to the supplied socket. First, chop the tag from the sprocket washer:

… then remove the paper from the front panel:

Now solder a link to the washer in a vertical position:

… then fit the BNC socket to the panel, with the washer aligned as such:

Finally, align the top panel with the PCB so the BNC socket pin and washer link drop into the PCB and solder them in:

If you want to use the servo mode, solder three short wires that can attach to a servo form the three “output” pads between the BNC and USB socket.

Finally, screw in the panels and you’re finished!

Using the function generator

Operation is quite simple, and your first reference should be the manual (manual.pdf). The display defaults to normal function generator mode at power-up – where you can adjust the frequency, offset, amplitude and type of output – sine, square, triangle, ramp up, ramp down, staircase up and down:

The ranges for all functions is 0~10 khz, except for sine which can hit 200 kHz. You can enter higher frequencies, such as up to 250 kHz for sine – but the results aren’t so good.

Instead of filling this review with lots of screen dumps from an oscilloscope to demonstrate the output – I’ve made the following video where you can see various functions being displayed on a DSO:

You can also create signals to test servos, with adjustable pulse-width, amplitude and cycle times. However you’ll need to solder three wires onto the PCB (next to the BNC socket area) to attach to the servo.

According to the user manual and various retailers’ websites – the FG085 can generate frequency sweeping signals. These are signals that sweep from a start to as finish frequency over a period of time. However the firmware on the supplied unit is old and needs updating to enable this function. You can download the firmware in .hex file format from here. Then go and dig up an AVR programmer and avrdudeAt the time of writing we had some issues with the signature not being recognised when updating the firmware, and solidly bricked the FG085. Our fault – so when that’s sorted out we’ll update the review – stay tuned.

There is also a USB port on the side – after installing CP2102 drivers in Windows we could connect at 115200 bps with terminal, however all the FG085 returned was the firmware version number. Perhaps later on the designers will update the firmware to allow for PC control. Somehow I wouldn’t bank on it.

Oh – if you’re wondering what DDS is - click here!

Conclusion

It’s an interesting piece of equipment. Putting the firmware upgrade issues to one side, the FG085 does what it sets out to do. During testing it worked well, and we didn’t come across any obvious inaccuracies during use.  The price varies between US$43 and $50 – so for that money it’s  a good kit. Just take care during construction and you’ll be fine.

The function generator is available in kit form or assembled, with or without panels from China. The kit version with panels is also available from Sparkfun (KIT-11394) and their resellers. Full-sized images available on flickr. This kit was purchased and reviewed without notifying the supplier.

In the meanwhile have fun and keep checking into tronixstuff.com. Why not follow things on twitterGoogle+, subscribe  for email updates or RSS using the links on the right-hand column? And join our friendly Google Group – dedicated to the projects and related items on this website. Sign up – it’s free, helpful to each other –  and we can all learn something.

The post Kit Review – JYE Tech FG085 DDS Function Generator appeared first on tronixstuff.



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