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.

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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:

Embedded Boards.(10/23) 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.

October has a 5th Tuesday, so we’re bringing you a bonus newsletter:
Digital Signage (10/30)  Digital signage ranks among the most dynamic areas of today’s embedded computing space. Makers of digital signage players, board-level products and other technologies continue to roll out new solutions for implementing powerful digital signage systems. This newsletter looks at the latest technology trends and product developments in digital signage.

Analog & Power. (11/6) 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 (11/13) 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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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. (10/16) 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.(10/23) 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.

October has a 5th Tuesday, so we’re bringing you a bonus newsletter:
Digital Signage (10/30)  Digital signage ranks among the most dynamic areas of today’s embedded computing space. Makers of digital signage players, board-level products and other technologies continue to roll out new solutions for implementing powerful digital signage systems. This newsletter looks at the latest technology trends and product developments in digital signage.

Analog & Power. (11/6) 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.

Build a Persistence-of-Vision Display

Using LEDs and PIC32

Learn how these two Cornell University students created a persistence-of-vision (POV) display. They found a way to fit an LED strip onto the mechanically rigid base of a box window fan. The POV display creates the illusion of an image and show anything from an analog clock to ASCII text and complex images.

By Han Li and Emily Sun

Visual feedback is a key aspect of human interaction in everyday life. With technology, the beauty of the visual world can be preserved with images and videos. We set out to create a persistence-of-vision (POV) display that is both multifunctional and easy to use, through the use of a large box fan. Box fans are often found by the window on hot summer days, and can be quite unique with the integration of a “cool” POV display. For our project, we found a way to fit a DotStar LED strip onto the mechanically rigid box base of a box fan. As such, the box fan serves as an ideal platform for a POV display, without needing to construct a well-calibrated rotating setup with a DC motor. The box fan also has preset settings for speed which is convenient for testing.

The novelty of this POV display makes it a good conversation starter, and it can be easily assembled and customized. The display creates an illusion of an image and shows anything from an analog clock to ASCII text and complex images.

In designing our POV fan display, the first thing we measured was the fan’s speed of rotation. This was calculated by flashing a blinking strobe light through the fan blades. On the slowest setting, the fan rotates at approximately 7 Hz, which is equivalent to 143 ms per rotation around the circular radius of the spinning fan. The angle resolution of the image generator of the POV display is limited by time constraints, so we defined 100 tick locations around the peripheral of the fan. Since the LEDs are programmed to light up twice per rotation, the images can be rendered twice as fast, thus increasing the refresh rate of the display to around 14 Hz—each pixel is blinking 14 times per second. For the human eye, the POV effect is achieved around 15 Hz, which means we are getting a decent result with our setup.

With an interrupt time of approximately 1 ms, and through the use of the Hall effect sensor that updates the period on each rotation, the positioning of displayed elements on the fan varies to at most 2.5 degrees. During testing, there are no observations of rotational jittering greater than 2.5 degrees with 100 display angles.

HARDWARE DESIGN

The hardware components are a box fan, DotStar LED strip, tri-state buffer, Hall effect sensor, 5 V battery bank, 9 V battery, a piece of 0.635 cm × 2.54 cm × 50 cm plywood and a Microchip Technology PIC32 microcontroller on a custom PCB [1].

Figure 1
Hardware setup with a closeup of Hall effect sensor and magnet placement

The custom PCB with the mounted PIC32 is secured onto the protoboard above a piece of Styrofoam to prevent short-circuiting (Figure 1). The protoboard itself contains the necessary power distribution and level shifting required for the LED strip. The DotStar LED strip must be driven at 5 V and takes about 60 mA per LED at full intensity. Because of the PIC32’s 3.3 V output, an ON Semiconductor 74LS125 tri-state buffer [2] is used as a level shifter. This is done by shorting the gate on the tri-state buffer to ground and powering the buffer with the 5 V rail (Figure 2). The 9 V battery is then connected directly to the custom PCB with the adapter, and the 5 V battery pack is connected to the power rail on the protoboard (Figure 1).

Figure 2
Schematic of hardware setup

In terms of mechanical setup, the front-facing grill on the box fan is removed for easy access. A piece of plywood is mounted onto the fan with two wood screws on the opposite side of the fan’s plastic centerpiece. The DotStar LED strip is secured to the plywood with zip ties. The metal ridges that secure the front facing grills are bent outward to allow for smooth rotation of the mounted plywood piece.  …

Read the full article in the October 339 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.

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. (10/2) 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 (10/9) 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. (10/16) 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.(9/25) 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. (10/2) 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 (10/9) 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.

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:

IoT Technology Focus. (9/18) 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.(9/25) 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. (10/2) 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.

DC Panel Meters Display Voltage, Current and Power

Murata Power Solutions has introduced its DCM20 series of multifunction panel meters. For DC systems, these meters measure DC voltage and current, calculate power up to 96 kW, and display values either manually selected or continuously cycling. The miniature panel-mount product provides an input voltage range of 0.5 VDC to 72 VDC, with 10 mV of resolution. The meter also supports current measurement ranges from 5 A to 1,200 A when used with an external user-supplied resistive shunt. Targeted for use in 12 V, 24 V or 48 V systems, out-of-the-box accuracy of the product is +/-1 % for voltage and +/-2 % for current.
Packaged in a rugged, one-piece polycarbonate housing, with dimensions of 2.1″  x 1.43″ or 53.3 mm x 36.3 mm, the DCM20 fits in ‘0U’ and ‘1U’ racks making it well-suited for laboratory instrumentation as well as industrial and telecom equipment. Threaded mounting studs and caged terminal blocks for application wiring ensure reliable operation in harsh environments.

Applications for the product include, but are not limited to, real-time monitoring and display of DC power in telecom power distribution systems, battery management/backup systems, laboratory instrumentation and alternative energy and marine installations.

The DCM20 features a large (0.36″ /9.2 mm) bright red display easily readable at 15 feet (5 m), with green or blue displays a future option. A front-panel capacitive touch sensor is incorporated for selection of operating mode, avoiding wear-out issues possible with a membrane of other mechanical switches. Using the touch sensor control, the user may configure the unit to display voltage, current or power, or set the unit to continually cycle between the three measurements.

The unit can be self-powered from the measured voltage or powered separately from an external power supply, which can range from 9 VDC to 72 VDC. When self-powered, the input voltage range that can be measured is 9 VDC to 72 VDC and when externally powered the lowest measurable input voltage extends down to 0.5V. Current consumption of the DCM20 is generally negligible compared with the measured current being typically 6 mA at 12 V and only 2 m A at 72 V input.

A DIP switch on the DCM20 allows selection of 16 different full-scale current readings from 5 A to 1,200 A providing compatibility with a wide range of external shunt resistors, available both from Murata and other manufacturers. A fine adjustment potentiometer is also provided to calibrate the unit to compensate for shunt resistor tolerance for improved system measurement accuracy. The external shunt resistor may be placed in either the ‘high’ or the ‘low’ side of the power system, as the DCM20 has a common-mode voltage range of 72 V. A jumper is available to set where the voltage is actually measured, either remotely or at the shunt resistor. In this way, high or low side current sensing is practical and power measurement can exclude losses in wiring and the shunt resistor itself.

Murata Power Solutions | www.murata-ps.com

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. (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.

IoT Technology Focus. (9/18) 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.(9/25) 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. (10/2) 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 (10/9) 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.

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:

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.

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.

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.

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:

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.

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.