Tindie

This LORA/GPS board designed by Dragino Tech is made for the Raspberry Pi and opens up a host of cool projects for that most popular of Single Board Computers. LORA (which stands for Long Range Radio) is a unique type of modulation that is best described as a frequency modulated FM chirp. Other types of modulation you may have heard of are PSK(Phase Shift Keying) and FSK( Frequency Shift Keying). LORA has advantages over those modulation schemes in that it increases the possible range and the receiver sensitivity.

The creators of LORA are a company called Semtech and they pitch it as the as a solution for IoT and M2M( Machine to Machine) networks. Currently GSM is used widely in M2M applications. IoT devices  communicate with standards like Bluetooth or WiFi. GSM has the advantage of high speed data transfer and long range but the power used to send and receive is too large to use with batteries for any decent length of time. Standards like Bluetooth and WiFi are lower in power usage, have good data transfer rates,  but are limited by range. LORA combines low power usage with the long range of several kilometers, at the cost of speed.

The highest possible speed with LORA is around 38 kbps. To put this speed in context, it would take 11 minutes to transfer a 3MB file (average mp3 file roughly). Speed isn’t what LORA is designed for and the benefits from having low power use and long range are huge. In applications with remote sensors( e.g. environment sensors, water level sensors, movement sensors), they only need to transmit a few bytes quite infrequently e.g. a sensor reading a few times per hour. LORA really shines here and could theoretically transmit for years on a single battery charge.

The chip that the LORA/GPS board uses for communication is the SX1276/SX1278 transceiver IC made by Semtech. The combinations of GPS with LORA open up the possibility of some really interesting projects like long range remote monitoring and tracking for example. You have long range, it can last for years on a single charge, and you know your exact location. What would you make?

Keep Reading ›

OSHCHIP combines an ARM cortex M0 processor and a Bluetooth Low Energy radio on a tiny PCB that is breadboard compatible. This board is great for those looking to get a start in ARM development especially since it comes with great documentation showing you how to hook everything up and some example code that you can compile yourself using the mbed online compiler.

The ARM processor and radio are combined into a single Nordic Semi nRF51822. The ARM processor runs at 16MHz and has 256Kb of Flash and 32Kb of SRAM. The radio included is a multi-protocol 2.4GHz compatible device. It works with the famous NRF24L series chips as well as supporting Bluetooth Low Energy (AKA Bluetooth Smart).

The OSHCHIP comes with 3 on board LEDs, a 10 bit ADC, and 14 GPIO pins to play with. The chip is programmed using the SWD (Serial Wire Debug) protocol. There is a SWD programmer available from OSHCHIP that is compatible with the Keil IDE and gives you some nice debugging options like breakpoints, examining memory, stepping through code etc.

Keep Reading ›

If you’re a fan of Star Wars, and happen to check out Ken.Do’s store, the first thing that will likely grab your attention is the “Deathstar-like Yo-yo”. Ken.Do recounts: “My son wanted a yo-yo. I made him a yo-yo.” Now you can have this 3D-printed yo-yo as well for $12 plus shipping. It’s really a clever design, and I’m honestly surprised we haven’t seen something like this mass-produced.

The rest of this store features some really cool stuff as well, including a hexapod robotic platform, as well as several quadcopter designs. The most unique of these is his Flying Ship robotics platform seen in the video below.

This robotics platform can float as well, with a sectioned hull that should survive some damage without sinking. The ship’s designer built this because he lives on a Pacific island surrounded by water, and has been experimenting with sonar mapping. Naturally something like this makes a great platform for these types of endeavors.

Keep Reading ›

This low cost programmable capacitor is something everyone should have in their parts box as it’s basically guaranteed you’ll have a use for it at some point. In a pinch, you can get by with using trimmer capacitors but these have the disadvantage that you don’t know the exact capacitance it’s set to. Just that it is somewhere in the given range.  Another disadvantage is that to be really flexible and have a big range of capacitance you would have to stock out your parts bin with a large number of trimmer pots.

This 5 decade variable capacitor gives you the huge range of 100 pF to 9.999uF to work with. You can fine tune it to within 100 pF which will be more than enough for most hobbyist use. The capacitors used have a tolerance of 5% on their capacitance. The uses of programmable capacitors are too numerous to possibly list. From working with op-amps to tuning a filter,  having one of these capacitors at hand will make your life easier and let you work faster.

Keep Reading ›

If you’re considering selling your devices online, there are many options out there, but if you want to test the market with knowledgeable customers who love cutting-edge hardware, and with the potential to grow beyond a niche electronics site, Tindie is the way to go. Gordon Garrity, after starting on Tindie, has now grown to the point where he has his own e-commerce site focused on Raspberry Pi audio accessories!

As another iteration in my seller interview series, check out what he has to say about his experience selling on Tindie:

How did you get started?

Over a few beers at home. I came up with an idea to deliver great audio quality to people using the Raspberry Pi, I met with Eben Upton (of the Pi Foundation) at a music hack event and it grew from there.

What is the best thing about selling on Tindie?

We had no clue on how to sell on the internet, nor how to set up a web presence. Neither did we have the funds to throw at a couple consultants to do it for us. Tindie makes it easy, real easy. It gave us an immediate e-commerce solution and allowed us to point potential customers at it. Tindie got us going and it gave us a presence in the right marketplace. Knowing that there was someone there, in the background, to help IF things failed was useful – even though we really didn’t have anything to panic about.

What is the worst?

I guess it was that both Tindie and us were growing and learning at the same time. We had a few hiccups but anything that was ever an issue was pretty quickly resolved. I missed having a telephone number [support is done through email] to contact someone on rather than just email though.

Have enough stock and communicate: You’ll not know the possible sales but at least tell people when you’ll have more. Work fast: Ship quickly

Anything you’d like to add?

If you don’t try it you’ll never know what’s possible. We’ve all but stopped selling on Tindie now as we’ve created our own e-commerce site [linked above]. As a stepping stone to greatness – Tindie helped enormously – thank you.

I suppose the takeaway from this is that if you have a great electronics idea, but don’t know how to sell it on the Internet, Tindie is here to help. Also, don’t panic.

We wish Gordon continued success in the future!

Keep Reading ›

The Berry IMU (Inertial Measurement Unit) allows you to measure orientation, velocity and magnetic fields. With this information you can work out which way is up, how fast you’re going, and which way is North. Just think of the possibilities. Add in a Raspberry Pi and you’ve got enough projects to keep you busy till the end of time.

The BerryIMU is a breakout board for the LSM9DS0, a motion sensing IC made by STMicroelectronics. It contains an accelerometer, a gyroscope, and a magnetometer to give you a grand total of 9DOF (Degrees Of Freedom). Whilst the breakout is designed to easily connect to a Raspi, it can also be easily hooked up to a microcontroller because it communicates over SPI or I2C.

IMUs are used in a whole range of applications because it turns out it’s really handy knowing your orientation and how fast you’re going. Some examples are balancing robots, quadcopters, and gesture sensing — there’s even one in your phone so you can play Pokemon Go.

Check out the video below of the BerryIMU hooked up to a Raspberry Pi:

Keep Reading ›

Murphy’s Law waiting to happen

Things can get very messy very quickly when trying to set up a wireless sensor network. Let’s say for example you are using the NRF24L01+ and want to have several nodes positioned around your house. Each node needs a microcontroller on it and a power source of some kind.

You can put together a circuit on a breadboard or some strip-board. But knock just one of those jumper wires loose or bridge a connection during soldering and you’ll spend ages when chasing down the problem. Having a dedicated board makes the process much less painful and reduces the number of things that can go wrong.

With electronics people start off learning Ohms law and so on, but the law they don’t teach is Murphy’s law. What can go wrong will go wrong.

Sure, you can spin your own board, but if your main goal is getting a stable sensor network up and running you start looking around for shortcuts. This offering takes care of microcontroller, regulated power, and two wireless module footprints in one small outline. The board supports the NRF24 wireless transceiver and a Bluetooth module.

The voltage regulator used is the MCP1703 made by Microchip. This regulator has a crazy low quiescent current draw of only 2uA meaning this board is suitable for use with battery powered applications that need to last a long time. With this board, all you have to do is plug in your NRF / Bluetooth transceiver, hook up a power source, program the microcontroller, and you are good to go. The ATmega328P has tons of Arduino Libraries available for it so you can get your project up and running quickly and easily.

Keep Reading ›

If you’re wondering what kind of experiments come out of a “Schlaboratory,” the answer would be 3D-printed pinhole cameras by a guy named Todd Schlemmer. I’ve been following him on Twitter for a while, and besides having an interesting fashion sense, he is quite the proponent of film photography.

As for his cameras, he has two models available on his store, both of which take medium format film. The terraPin, available with two different focal length extensions, is larger than the terraPin Bijou, which does not have this capability. As the description of his store puts it, these cameras are “Hand crafted…with a [3D-printing] robot.” Though perhaps not for everyone, this type of photography produces some very interesting images.

If you’d like to see if this form of photography is right for you before purchasing one of “The Schlem’s” excellent models, Kodak has instructions for making one of these simple devices out of a box or can. Or if you have a 3D-printer, you can print one based on Schlemer’s design for the original or the Bijou. It’s hard to deny the benefits of digital photography (like instant feedback), but film definitely has its place if you have the patience to wait for it to develop!

Keep Reading ›

Sometimes a project calls for using a wall wart and battery power. For example if you’re testing a wireless node, it would be convenient to have it run from a USB supply during the initial build, but for field testing switch over to battery power.

LifePO4 with motor

Cobbling together some questionable mobile power source just for this very reason takes time and energy away from the meaningful prototyping at hand. What you really want is a portable, rechargable option. The LiFePO4wered/USB board is an interesting offering in these circumstances. If you’re already planning to use a Lithium battery to power your 3.3V design this is probably the perfect addition to your prototyping tools. It’s a 3.2V 550mAh battery and integrated charger. The type of battery used is a LifePO4 which is an interesting piece of technology in and of itself.

The LifePO4 battery is based on lithium-ion chemistry but has several advantages over other lithium-ion based batteries. The cell has a near constant voltage of 3.2 volts during its entire discharge cycle, perfect for use with 3.3v micro-controllers and avoiding the use of voltage regulators. Due to the fact that the cell maintains this pretty constant voltage, you can draw every last bit of power out of the battery before the cell voltage drops too low.

Keep Reading ›

In yet another Tindie seller interview, I was able to catch up with Paul Evans, who runs the “Leonerd” store. Though you might think that his store caters to extremely smart lions, he instead describes his site as having “tools and equipment that might be used by electronics hobbyists and professionals.” He adds that his products are generally something that he makes for himself, then decides to sell to the public later.

Though certainly designed for function, one of his more visually appealing tools is shown in the image above, an oscilloscope current probe adapter. You can find out more about it here. As for more about Paul and his store, here are a few more bits from our email “interview.”

How did you get started?

I decided to try using a commercial PCB manufacturer to make a board
design, instead of just using stripboard – mostly because a part I
wanted to use only came in SOIC8 and not DIP8. The manufacturer would
do 3 boards, but I only wanted 1. So then I decided I’d try building up
the other two and selling them anyway. It all went from there – I now
mostly design things I want with the aim of also selling them, so I
tend to try to make them a bit more generic, or better documented.

What is the best thing about selling on Tindie?

Low volume specialism. You can make literally just one or two of a
thing, and manage to sell it. Other more commercially-oriented methods
would be looking at runs of 100 or 1000 at least, before they’d even
consider it.

What is the worst?

Probably writing descriptions for new products. Or at least,
thinking up what wording to put. I’m terrible at it. I often spend
hours thinking and rewriting a bunch of times, then usually I’ll still
end up editing it a bunch more times after it’s published.

Any tips for other sellers?

I find a lot of variation in “productisation” between sellers; the
amount of effort that’s gone into changing that one-off personal
prototype into something to sell. A few little things can go a long way.

Consider the fact that other people have to work out how to use your
product. Maybe put some more time into careful design of silkscreen pin
names, or even a little printed instruction leaflet.

Consider the overall look-and-feel. Maybe a case is appropriate;
usually moreso for self-contained equipment than things like modules
and breakout boards.

Also, laser-cut solder-paste stencils have become really cheap lately.
Consider using those. The quality of my soldering went up noticeably
when I switched to that for surface-mount components. Faster too 🙂

Thanks Paul, for your thoughts on Tindie! Hopefully it will help other sellers with their stores, and we wish you the best with yours.

Keep Reading ›