Meet NanoPi NEO The New Hero – The 8 $ Computer

Meet NanoPi NEO the latest member in NanoPi family from FriendlyARM.

NanoPi-NEO-layout

NanoPi NEO features Allwinner H3 CPU, a Quad-core Cortex-A7 Up to 1.2GHz CPU.
It’s available with 256MB DDR3 RAM or 512MB one with additional 2$ for the last one.

The board has 10/100M Ethernet RJ-45 jack, USB host type A connector, MicroUSB connector for data transmission and power input, one MicroSD slot, serial debug header and 36 pins for GPIO.

NanoPi-NEO_en_pinout

The supported OS for NanoPi NEO are: Ubuntu Core, armbian and FreeBSD.

Raspberry Pi Zero - Image courtesy of Adafruit
Raspberry Pi Zero – Image courtesy of Adafruit

Raspberry Pi Zero, the 5$ computer, had  Broadcom BCM2835 1GHz ARM11 single-core processor, 40-pin GPIO header, mini-HDMI socket for 1080p60 video output and two MicroUSB one for power and one for data transmission with 40mm  x 40mm dimension.

NanoPi price is 8$ plus 5$ for shipping, you can order some accessories like MicroSD card memory and USB power adapter from the product page.

Product Page

NanoPi NEO Schematic
Via: elektormagazine

1Hz to 30KHz Wave Generator Using Arduino

Wave generator is one of the most needed tools in our electronics labs, you can buy a fully functional ready made one or make a simple one using your Arduino.

Ard_waveGen

Joekutz over Hackaday.io created a simple wave generator using Arduino powered from 9V battery and produces amplified and non amplified signals. This generator uses the 8-bit resistor ladder, aka R2R, DAC with 0.0195V step, knowing that Vout of R2R DAC is Vout = Vref × VAL / 2^N  Where N = 8 (hence 2^8 = 256) and Vref = 5.0 V.

R2R_sch
Image Source – “Arduino Waveform Generator” Instructable

Joekutz used the “Arduino Waveform Generator” instructable, but he added to the original project design a LCD display, a speaker to hear the generated wave and edited the way how user sets the waveform and frequency.

Joekutz decided to hack a cheap calculator LCD and to use it in his project, he found out how to emulate a press of “CE, +, = and 1” Keys using Arduino, so he can display any number using this hack, for example displaying 123 on the LCD means the following sequence: 111 + 11 + 1.

Ard_waveGen_parts

He created an Arduino library for his hack. You can see the below video from Joekutz explaining LCD hack:

In the below video Joekutz demonstrates the project:

The mechanical work in this project included designing a cheap plywood case using Inkscape and designing a switches knobs using FreeCAD.

You can download the Arduino Library and sketch files from the project page on Hackaday.

RELATED POSTS

How to control Arduino board using an Android phone

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Kerimil, user on Arduino Forum, submitted his project which focuses on establishing communication between an Arduino board and an android mobile using bluetooth:

The idea is to gain access to hardware on Android devices (accelerometers, gyro, wifi connectivity, gps, GPRS, touchscreen, text to speech and speech to text) and/or use it to relay data to the internet. MIT’s app inventor was used to write a custom app in this example. The code can be easily modified to create your own apps.

How to control Arduino board using an Android phone – [Link]

Filtering Noisy Arduino Measurements

All
@ megunolink.com discuss about noise in analog input of arduino and how to filter it. He examines 3 filtering algorithms: Averaging, Running average, Exponential filter and provides the code to achieve that.

Measurements from the real world often contain noise. Loosely speaking, noise is just the part of the signal you didn’t want. Maybe it comes from electrical noise: the random variations you see when calling analogRead on a sensor that should be stable. Noise also arises from real effects on the sensor. Vibration from the engine adds noise if you’re measuring the acceleration of a go-kart, for example. Filtering is a method to remove some of the unwanted signal to leave a smoother result.

Filtering Noisy Arduino Measurements – [Link]

DIY USB power bank from laptop battery

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DIY USB power bank made from an old laptop battery @ DoItYourselfGadgets:

A situation many can relate to: an empty smartphone battery and no outlet around! That’s exactly why I recycled an old laptop battery into an USB power bank.
This article will show you the basic powerbank circuit consisting of Lithium cell charging circuit, boost converter and toggle switch as well as my improved version with self activating boost converter and LED status indicator and homemade housing.

DIY USB power bank from laptop battery – [Link]

Reverse Engineering a Simple Four Function Calculator: die decap

4func

Electronupdate did a teardown and analysis of a cheap four function calculator:

It’s such an amazingly old looking die.
Even with 400x magnification it would not be too hard to reverse engineer back to a schematic! This must be a very old design indeed. When one thinks of high-tech it’s always the new-new thing… however some designs can be very old indeed and still be in production.

Reverse Engineering a Simple Four Function Calculator: die decap – [Link]

Whoa Board: Dream With Touch Sensing EL Wire, Panels, Paint

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The Whoa Board makes things glow. It also makes glow-y things sense touch. It’s an open prototyping platform for wearable electronics!

Turn any EL (Electro-Luminescient) material into a touch sensor with no additional hardware. It’s an open prototyping platform for wearable electronics! Open source and Arduino IDE compatible.

Whoa Board: Dream With Touch Sensing EL Wire, Panels, Paint – [Link]

ElbSupply – Linear Bench Power Supply With Constant Current and Voltage Modes

A lot of power supply designs are here and there on the Internet, but not all of them have constant current and voltage modes. You can read the following Q&A in electronics.stackexchange to learn what constant current and voltage modes mean.

Elia over Hackaday.io built a linear bench power supply with the following features:

  • Output voltage range: 0 – 15V.
  • Output current range: 0 – 3A.
  • Constant voltage with current limiting and constant current modes.
  • LCD interface.

EliaSupply

ElbSupply Inside

EliaSupply_sch

LT3083 the adjustable 3A low dropout regulator from Linear technology is used to provide the output voltage.
To reduce the power dissipation in the linear regulator, supply voltage is not connected directly with the adjustable LDO regulator input. Elia added a stage to reduce the input voltage of LT3083 to (Vout+2) using a buck converter. This Buck converter, TI TPS54331, is configured to follow the output voltage of the adjustable regulator plus 2 volts as an output voltage of the buck converter.

ATmega8 MCU is used to drive the 16*2 LCD, read values from the rotary switch STEC12E08, read user buttons and to produce the reference PWM signals for voltage and current.

These PWM signals are converted to analog value, the way used to convert the PWM signal to an analog value proportional with PWM is by using “resistor, a capacitor and an opamp”.
LM334, an adjustable current source, used in the output voltage of LT3083. Elia said in a log, it is needed for stable operation, the LT3083 needs a minimum load current of 1mA.

Design Files and Source Code

elbsupply-revB-bottom

ElbSupply is an Open-source hardware project. You can download the source files from the GitHub repository.

PCB and schematic are designed using KiCAD and source code was written in C with state machine code methodology.
[Project Page]

DIY USB to TTL Converter

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ams31 @ instructables.com show us how to build a DIY USB to TTL Converter using CH340G IC.

Lots of USB to TTL modules are available in the market based on various chips like PL2303, FT232, CP2102 and CH340g. I have decided to use CH340g IC. Low costing clones of Arduino UNO & Arduino Nano also uses CH340g IC. And this IC is now easily available in India. Reasons for not using other converter IC’s.

DIY USB to TTL Converter – [Link]