Tuesday’s Newsletter: IoT Tech Focus

Coming to your inbox tomorrow: Circuit Cellar’s IoT Technology Focus newsletter. Tomorrow’s newsletter covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

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You’ll get your IoT Technology Focus newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(8/28) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (9/4) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (9/11) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Tuesday’s Newsletter: Microcontroller Watch

Coming to your inbox tomorrow: Circuit Cellar’s Microcontroller Watch newsletter. Tomorrow’s newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Microcontroller Watch newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

IoT Technology Focus. (8/21) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(8/28) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (9/4) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Tuesday’s Newsletter: Analog & Power

Coming to your inbox tomorrow: Circuit Cellar’s Analog & Power newsletter. Tomorrow’s newsletter content zeros in on the latest developments in analog and power technologies including ADCs, DACs, DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Analog & Power newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Microcontroller Watch. (8/14) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. (8/21) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(8/28) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Bonus Newsletter Tomorrow: PCB Design

Coming to your inbox tomorrow: July has a 5th Tuesday . That’s means there’s an extra Newsletter this month! The bonus topic is PCB Design. The process of PCB design is always facing new complexities. Rules-based autorouting, chips with higher lead counts and higher speed interconnections are just a few of the challenges forcing PCB design software to keep pace. This newsletter updates you on the latest happenings in this area.

Also, we’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your PCB Design newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter switches its theme each week, so look for these in upcoming weeks:

Analog & Power. (8/7) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch. (8/14) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. 8/21) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards. (8/28) This newsletter content focuses on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Next Newsletter: Embedded Boards

Coming to your inbox tomorrow: Circuit Cellar’s Embedded Boards newsletter. Tomorrow’s newsletter content focuses on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your
Embedded Boards newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

July has a 5th Tuesday, so we’re bringing you a bonus newsletter:
PCB Design (7/31) PCB design tools and methods continue to evolve as they race to keep pace with faster, highly integrated electronics. Automated, rules-based chip placement is getting more sophisticated and tools are addressing the broader picture of the PCB design process. This newsletter looks at the latest technology trends and product developments in PCB design tools.

Analog & Power. (8/7) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (8/14) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. (8/21) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Tuesday’s Newsletter: IoT Tech Focus

Coming to your inbox tomorrow: Circuit Cellar’s IoT Technology Focus newsletter. Tomorrow’s newsletter covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your IoT Technology Focus newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(7/24) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

July has a 5th Tuesday, so we’re bringing you a bonus newsletter:
PCB Design (7/31) PCB design tools and methods continue to evolve as they race to keep pace with faster, highly integrated electronics. Automated, rules-based chip placement is getting more sophisticated and tools are addressing the broader picture of the PCB design process. This newsletter looks at the latest technology trends and product developments in PCB design tools.

Analog & Power. (8/7) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (8/14) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

U-Blox Modules Selected for IoT Development Board Pair

U‑blox has announced that its modules will be at the core of two new developer boards. The boards, which are designed and produced by Seeed, one of China’s largest distributors of microelectronic components for the international developer and maker communities, deliver cellular communication and positioning capabilities for a wide range of applications in the IoT

The first of the two development boards is a Raspberry Pi HAT designed to augment Raspberry Pi computers with cellular communication as well as cellular‑based positioning services. The board will be released in multiple variants (USA AT&T, USA Verizon, Europe) based on the u‑blox LARA‑R2 LTE Cat 1 module series.
The second board, the WIO LTE Cat M1 / NB1 tracker, provides the essential hardware to make low‑power location tracking devices for people, pets, and assets. It can be programmed using the Arduino IDE and is also Espruino (JavaScript) compatible. The board uses the u‑blox MAX‑M8Q GNSS module to determine position, integrating signals from multiple GNSS satellite constellations, and connects to the cellular network using the u‑blox SARA‑R4 LTE Cat M1 / NB1 module. Developers and businesses can customize the standalone board and have it manufactured through Seeed’s services to create solutions tailored to their specific needs.

U-blox | www.u-blox.com

Tuesday’s Newsletter: Microcontroller Watch

Coming to your inbox tomorrow: Circuit Cellar’s Microcontroller Watch newsletter. Tomorrow’s newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Microcontroller Watch newsletter issue tomorrow.

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Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

IoT Technology Focus. (7/17) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(7/24) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

July has a 5th Tuesday, so we’re bringing you a bonus newsletter:
PCB Design (7/31) PCB design tools and methods continue to evolve as they race to keep pace with faster, highly integrated electronics. Automated, rules-based chip placement is getting more sophisticated and tools are addressing the broader picture of the PCB design process. This newsletter looks at the latest technology trends and product developments in PCB design tools.

Analog & Power. (8/7) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Tuesday’s Newsletter: Analog & Power

Coming to your inbox tomorrow: Circuit Cellar’s Analog & Power newsletter. Tomorrow’s newsletter content zeros in on the latest developments in analog and power technologies including ADCs, DACs, DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Analog & Power newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Microcontroller Watch. (7/10) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. (7/17) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(7/24) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Next Newsletter: Embedded Boards

Coming to your inbox tomorrow: Circuit Cellar’s Embedded Boards newsletter. Tomorrow’s newsletter content focuses on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your
Embedded Boards newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Analog & Power. (7/3) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (7/10) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. (7/17) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Tuesday’s Newsletter: IoT Tech Focus

Coming to your inbox tomorrow: Circuit Cellar’s IoT Technology Focus newsletter. Tomorrow’s newsletter covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your IoT Technology Focus newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(6/26) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (7/3) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (7/10) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Passive Infrared Sensors

Homing in on Heat

One way to make sure that the lights get turned off when you leave a room is to use Passive Infrared (PIR) sensors. Jeff examines the science and technology behind PIR sensors. He then details how to craft effective program code and control electronics to use PIR sensors is a useful way.

By Jeff Bachiochi

“The last one to leave, please turn off the lights.” How many times did you hear this while growing up? It’s an iconic phrase sometimes used to suggest the end of life, but as I remember it, just an effort to save electricity. I would always use the logic that bulbs burn out during the initial surge current and not necessarily from remaining on, but that logic never worked on Mom. To this day I am obsessive about turning lights off (thanks Mom!). To that end I tried installing Passive Infra Red (PIR) sensors to handle this automatically. After being inundated with complaints (from my wife Beverly) about lights turning off “while I’m still in the room,” I gave up.

While PIR devices are sensitive to heat (infrared)—the human body’s radiation is strongest at a wavelength of 9.4 µm—they are based on the heat source moving past the sensor. Let’s look at a typical PIR sensor element to see how this works. The RE200B PIR sensor comes in a TO-5 package. Manufactured by Glolab, this device actually contains two sensors as seen in Figure 1.

FIGURE 1
The metal tab on the TO-5 can indicates the X-axis plane across both sensor elements. The window filter material is optimized for approximately 10 μm wavelength.

Each pyroelectric sensor is made of a crystalline material that generates a surface electric charge when exposed to heat. When the amount of radiation striking the crystal changes, so does amount of charge on the input to a sensitive FET device built into the sensor. The two elements are in series with the FET input connected to their junction. With this configuration and a wide (138-degree) field of view, whatever ambient light falls on both the sensors is canceled out. The sensor elements are sensitive to radiation over a wider range so a filter window is added to the TO-5 package to limit detectable radiation. As a standalone this device is not very useful. We need a way to interrupt the heat source from hitting both sensor elements at the same time.

Anyone familiar with opto encoders already understands how this works. Opto transmitter/receiver pairs are placed on opposite sides of a spoked wheel. Light passes between the spokes as it rotates between the pair. A second pair is placed such that when one light path is blocked by a spoke, the other light path is between spokes. As the spoked wheel rotates, the opto device’s output alternates between one coupled pair and the other. With some logic on the opto outputs, you can tell both direction and speed of the rotation. Creating the same kind of “picket fence” in front of the infrared (IR) sensor elements can cause the radiation to be alternately blocked and passed to each sensor. The trick will be to design the slat width and placement to give the desired effect.

Fresnel Lens

Figure 2
Lenses of large aperture and short
focal length are massive. The bulk
of the material can be eliminated as
long as the lens’ curve stays the same.
This can be accomplished by a series
of annular lens rings or the special grinding pattern on a single blank.

A lens could be used to artificially reduce the field of view, by collecting and focusing it into a smaller spot. Move an object in front of the lens left to right and the spot moves right to left, behind the lens. If the spot passes over the two sensor elements sequentially, voilà—each sensor will produce a push or pull at the center tapped output. And that is something we can detect. A single lens would create one sensitive area out in front of the device. This might be just what you are looking for. However, to be sensitive to a wider range we must have multiple lenses. Since glass is opaque to IR we can’t use a typical glass lens. It turns out that polyethylene type materials do pass IR light and can be formed in various Fresnel lens patterns.

The idea for the Fresnel lens goes back to the French mathematicians of the late 18th century. This was an attempt to make lenses thinner while retaining the optical quality of the original. Figure 2 shows how unnecessary thickness is removed from an original lens without changing the lens’ curvature. In the early 19th century this idea was adapted for use in lighthouses by Augustin-Jean Fresnel. The thin cross section of the Fresnel lens makes it ideal for PIR lenses. …

Read the full article in the June 335 issue of Circuit Cellar

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Note: We’ve made the October 2017 issue of Circuit Cellar available as a free sample issue. In it, you’ll find a rich variety of the kinds of articles and information that exemplify a typical issue of the current magazine.

Tuesday’s Newsletter: Microcontroller Watch

Coming to your inbox tomorrow: Circuit Cellar’s Microcontroller Watch newsletter. Tomorrow’s newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Microcontroller Watch newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

IoT Technology Focus. (6/19) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(6/26) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (7/3) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Tuesday’s Newsletter: Analog & Power

Coming to your inbox tomorrow: Circuit Cellar’s Analog & Power newsletter. Tomorrow’s newsletter content zeros in on the latest developments in analog and power technologies including ADCs, DACs, DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

Already a Circuit Cellar Newsletter subscriber? Great!
You’ll get your Analog & Power newsletter issue tomorrow.

Not a Circuit Cellar Newsletter subscriber?
Don’t be left out! Sign up now:

Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Microcontroller Watch. (6/12) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.

IoT Technology Focus. (6/19) Covers what’s happening with Internet-of-Things (IoT) technology–-from devices to gateway networks to cloud architectures. This newsletter tackles news and trends about the products and technologies needed to build IoT implementations and devices.

Embedded Boards.(6/26) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Next Newsletter: Sensors and Measurement

Coming to your inbox tomorrow: Circuit Cellar’s Sensors and Measurement newsletter.
May has a 5th Tuesday, so we’re bringing you this bonus newsletter beyond our normal four rotating weekly subject areas. While sensors have always played a key role in embedded systems, the exploding IoT phenomenon has pushed sensor technology to the forefront. This newsletter looks at the latest technology trends and product developments in sensors and measurement.

Bonus: We’ve added Drawings for Free Stuff to our weekly newsletters. Make sure you’ve subscribed to the newsletter so you can participate.

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You’ll get your
Sensors & Measurement newsletter issue tomorrow.

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Our weekly Circuit Cellar Newsletter will switch its theme each week, so look for these in upcoming weeks:

Embedded Boards.(5/22) The focus here is on both standard and non-standard embedded computer boards that ease prototyping efforts and let you smoothly scale up to production volumes.

Analog & Power. (6/5) This newsletter content zeros in on the latest developments in analog and power technologies including DC-DC converters, AD-DC converters, power supplies, op amps, batteries and more.

Microcontroller Watch (6/12) This newsletter keeps you up-to-date on latest microcontroller news. In this section, we examine the microcontrollers along with their associated tools and support products.