Iterated-map circuit creates chaos

the Design Idea circuit shown below is a simple implementation of an iterated unimodal map, reminiscent of the logistic or Verhulst map encountered in the study of nonlinear dynamics. It is useful to show chaotic discrete-time dynamics to students, or as a random number generator. Specifically, the circuit implements: Vk+1 = rF(Vk), where F is a nonlinear unimodal function (a “bump”), implemented by the cir ...

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Make Your Own Smartwatch From An Old Cell Phone

Step 1 Scavenging Parts What I’d like to do for this crazy/ambitions project is turn an old cell phone into a smartwatch. So obviously an old cell phone is required. The primary reason for this project is simply that I had an old cell phone laying around and wanted to find a creative way to repurpose it. The one I had is a Nokia 1100, but most other old cell phones would work, so long as you can find the sc ...

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PIC32MM Family of Low Power, Low Cost, 32-bit Microcontrollers

For applications demanding low power and longer battery life, the PIC32MM has sleep modes down to 500 nA. Applications with space constraints will benefit from the small 4x4mm package options. The PIC32MM devices include core independent peripherals, designed to offload the CPU for lower power and flexible system design, such as Configurable Logic Cells (CLC) and Multiple-output Capture Compare PWMs (MCCPs) ...

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How To Select an Inductor

When I was working on the the latest version of the Common Parts Library, I realized that it would be helpful to explain why you might pick one type of inductor over another. We started off this series by writing “How to select a capacitor,” followed by “How to select a resistor,” and are continuing with a close look at inductors. In this blog, we will explain all the different types of inductors, their mer ...

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VXO — based PLL Frequency Synthesizer for 7 MHz

In EMRFD, 4.10, Wes provides the schema for a versatile VXO - extending frequency synthesizer. Although, I referred him to Wes for help, a reader asked me some questions and I ended up designing some pieces for him. In order to test some of my ideas, I made a VXO - based synthesizer that tuned from 6.99 to 7.103 MHz using only parts I had in stock. Above — Output of the 1 MHz CMOS clock applied as the refer ...

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The future of IC design

To celebrate 60 years of EDN, we’re looking into the future to predict what advancements will be made in IC Design in the next 60 years. By 2076 3-D room-temperature, superconducting, quantum, neuromorphic, and photonic mixed-signal devices will be the common denominator for all integrated circuit designs. Design tools will be so sophisticated that even novice designers will be able to mix and match these t ...

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32Mb ESP01 and Sonoff

Some time ago I passed comment in here about converting an ESP-01 to 32Mb  (or 4MB).  And here it is in the flesh – a 32Mb ESP-01 – and also – at last – Sonoff Upgrades. Now, why would you want to do all of that? I would suggest only if you happen to have lots of ESP-01 units lying around – and I’ll bet quiet a lot of you do. As for the Sonoffs – well, put it this way, I just ordered another 10 chips! I sto ...

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HC-12 433MHz wireless serial communication module configuration

HC-12 are cheap 433MHz wireless serial port communication modules with a range up to 1800m in open space. Each costs about $5 when bought from China, and 2 of them can create wireless UART link that can be used, for example, to transfer telemetry data from UAV. Or drive IoT device. Or connect sensors. Or whatever else one can think of. It is based on SI4463 RF chip, has build in microcontroller, can be conf ...

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OPTOGENETIC HARDWARE SETUP

Arthur English's group at Emory has developed a custom device that they have used for stimulating peripheral nerves optically in anesthetized mice using a standard optical fiber. The device is compact, rechargeable battery-operated, and controlled either manually or by computer using an analog input. Essentially, laser LED illumination is coupled to an optical fiber by a collimator and can be attached to a ...

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4 Channel RF Remote Controller

4 Channel RF remote built using PT2262 and PT2272-M4 IC from Princeton technology. PT2262 used as Encoder (Transmitter) and PT2272-M4 Decoder (Receiver) ICs are heart of the project. The receiver provides 4 channel Momentary outputs. All outputs are TTL level can be interface with other circuits or relay board. Transmitter works with 5V to 12V DC. Receiver works with 5V DC. When any of SW1-SW4 (S1-S4) tact ...

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