An inexpensive single board computer which connects to a composite video monitor, keyboard, and SD card by Jack Eisenmann:
I created the DUO Light as a low cost platform for hobbyists to create fun and useful software. The DUO Light is ideal for anyone who wants a low power computer with video output and keyboard input.
The DUO Light is a hybrid of the Arduino UNO and the Raspberry Pi, but costs less than each. At the heart of the DUO Light is the ATMega328, the same microcontroller as in the Arduino UNO. This chip connects to a variety of peripheral devices, including a composite video monitor and SD card (in a similar fashion to the Raspberry Pi), PS/2 keyboard, and general purpose I/O ports. The second chip onboard is a 64 KB serial SRAM, which also connects to the ATMega328.
DUO Light Computer - [Link]
Davide Gironi writes:
DS18B20 is a programmable resolution 1-wire digital thermometer.
It has an operating temperature range of -55°C to +125°C and is accurate to ±0.5°C over the range of -10°C to +85°C.
This library is an AVR implementation to retrive temperature from DS18B20.
Built using the reference document: “Using DS18B20 digital temperature sensor on AVR microcontrollers” by Gerard Marull Paretas, 2007.
A DS18B20 1-wire digital thermometer AVR ATmega library - [Link]
by Vadim Panov:
Back when I was only starting to dabble in electronics, I needed a project that would meet the following requirements:
simple to make;
original (i.e. done entirely by myself from scratch);
containing a microcontroller;
and maybe the most important of all, useful. I’ve had enough devices I assembled just to dismantle the whole thing a month later.
The thing I came up with at the time was a light swich for my room controlled over an IR remote from TV. Remote that I had used RC-5 protocol, hence the firmware is suited for any RC-5 compatible remote.
Everyone is familiar to the everliving problem with switching the lights off in your room before going to bed and stumbling back across the room. The IR switch I describe here solves that problem, and I can definitely tell that this project was a success – I am still using it with no regret.
Infrared remote controlled light switch with ATTiny2313 - [Link]
Embedded modules may surprise you by their contribution and an overall costs savings.
As we know „embedded module“ is a quite wide term and it can represent a powerful microcomputer with OS, but it can also be a significantly simpler module with a microcontroller and peripherals, still able to add considerable functionality to a target device.
Typical representatives of useful modules, which add a lot – without big costs are so called quick start modules from company Embedded Artists. Their contribution is in a ready-made „tuned up“ PCB containing for example in case of module LPC4088 QuickStart Board (EA-QSB-016) the microcontroller itself (Cortex- M4), memory, display controller and many interfaces like Ethernet, USB, UART, SPI, CAN, PWM, Analog In/Out, I2C, XBee compatible connector and other.
Especially at low and mid-volume production batches their contribution is mainly in the fact, that it is a really proven solution with a guaranteed operating temperatures range, proper ESD protection and mainly – supported by a wide scale of development tools (free). In case of solving of problems, it´s still possible to contact customer support of company and a lot of hints for successful usage, source codes and libraries can be found directly on the producer´s website.
Try to go easier way - [Link]
herpderp shares his waveform generator:
Here is my last project, a tiny waveform generator based on my previous project and some components:
– An AD9834 (DDS chip with sinus/triangle output)
– 2 x AD5310 (10bit DAC: one for the Vpp control, another one the offset control)
– 3 x LM7171 (Fast OPA)
– 3 x LT1616 (switching regulator: +5V, +7V, -7V)
This waveform generator is directly powered by a standard 12V jack and is capable of outputting a 10Vpp signal at 1MHz (between -5V and +5V, sinus waveform, no load). Above 1MHz, the output starts fading, reaching only 9Vpp at 4MHz (maximal frequency). Frequency, amplitude and offset are digitally controlled through the smart TFT.
Three “basic” waveforms are provided: sinus and triangle, coming from the DDS chip (0.1Hz to 4MHz, 0.1Hz step), and PWM coming from the microcontroller (0.1Hz to 1MHz, variable steps).
Tiny waveform generator - [Link]
An interesting open source NFC project is seeking for funding on kickstarter.
MicroNFCBoard is an integrated development platform that makes it easy to use Near Field Communication or NFC (What is NFC? see below for more info). It contains a NFC transceiver, a microcontroller and all the software you need to use NFC.
It can be used with an Arduino, Raspberry Pi, mbed or PC/Mac. There is also a powerful ARM Cortex-M0 microcontroller onboard so it can work on its own and you can connect a bunch of things to the board using its various peripherals.
MicroNFCBoard – Easy NFC for the Internet of Things - [Link]
by MakerSpark Industries @ instructables.com:
This Instructable is about how to create an Arduino PIR motion sensor for your room or office, using parts available from your local Radio Shack! Whether you’re looking for a cool and easy-to-build security sensor, or an awesome first project to dive into the world of Arduino, Microcontrollers, and electronics, this project is for you. (This project really is easy. Take it from me, I’m 12, and I’ve only had my Arduino for a week and a half.)
Arduino PIR Motion Sensor - [Link]
Everytime we need to test a stepper motor controller we have to connect it to the parallel port of the computer or to a function generator to obtain the necessary pulses the realize the movements of the stepper.
This is a quicker method to check a controller integrity. Simply to make the life easier here is a square wave signals generator. A potentiometer or a trimmer regulates the pulse generation of the 12F675 microchip (a square wave, between 20 hz and 3khz). Ok, there are thousands of different ways to create a pulse generator, but we had a lot of microcontrollers.
12F675 pulse generator - [Link]
The ULN2003A 7-way (or ULN2803A 8-way) darlington driver is usually the go-to chip of choice when you need to switch any high current load from a microcontroller’s GPIO. It provides seven darlington driver stages to give low-side switching and even includes seven common-cathode clamp diodes to snub voltage spikes when high inductance loads are used. Texas instruments have recently introduced an alternative device which is said to be the industry’s first seven-channel, NMOS low-side driver chip.
The TPL7407L is a high-current NMOS transistor array. It contains seven NMOS transistors that feature high-voltage outputs also with built-in clamp diodes. The input stage is compatible with GPIO logic levels ranging from 1.8 to 5.0 V and the maximum rating of each NMOS channel is 600 mA. Several outputs can be paralleled if it is necessary to sink higher levels of load current. The TPL7407L’s key benefit is its improved power efficiency and lower leakage compared to bipolar darlington drivers.
Efficient NMOS Driver Array - [Link]
Dan over at HackAday documented his single chip computer project with the PCBs from DirtyPCBs:
A single AVR microcontroller (the ATmega 1284P) has been used to create a standalone computer system which runs the BASIC programming language. The 1284P runs TinyBASIC Plus, generates RCA video signals (using TVout) and reads PS/2 keyboard input. A single sided PCB was used to hold all the components meaning it is easy to manufacture the computer at home using processes such as photo-etching. Additionally, the component count is fairly low and only one IC is required (the 1284P).
Single chip AVR BASIC computer - [Link]