This Application Note from Microchip provides a reference design for building a non-invasive blood pressure meter using the PIC24FJ128GC010 microcontroller and MCP6N11 instrumentation amplifier. [via]
A digital blood pressure meter measures systolic and diastolic pressures by oscillometric detection. Microchip’s digital blood pressure meter demo can measure blood pressure and pulse rate during inflation. The Measurement While Inflating (MWI) principle reduces overall measuring time, which in turn reduces discomfort caused by the pressure in the cuff.
Digital blood pressure meter design using PIC microcontroller - [Link]
by Jordan Dimitrov @ edn.com:
While most carbon dioxide sensors use IR technology, electrochemical sensors are a serious competitor because of their high sensitivity, wide measurement range, and low price. As a rule, electrochemical sensors connect to a microcontroller through a buffer amplifier with an extremely low bias current (<1pA). The micro is needed to linearize the logarithmic response of the sensor. A good example of this approach is the SEN-000007 module from Sandbox Electronics, which uses an MG-811 CO2 sensor from Hanwei Electronics. Reference 1 reveals the circuits and the code, but does not specify accuracy.
Antilog converter linearizes carbon dioxide sensor - [Link]
who would ever imagine that global cultural and economic revolution would spring from the tranquil fields of piedmont, italy, in tiny towns nestled against the stunning backdrop of the alps? but that’s exactly where arduino, the system of microcontrollers revolutionzing the maker movement and pioneering the concept of opensource hardware, was born in 2005 and continues to make its home today.
arduino’s story is unusual to say the least. five colleagues, seeking to empower students with the tools to create, developed the platform in 2005. now distributors estimate that over one million arduinos have been sold, and the arduino community is among the most resilent and inventive on the internet. forums like instructables and arduino’s own scuola connect enthusiasts to learn from one another, and arduino users build on the platform to open up new creative possibilities.
Arduino factory + production tour in turin, italy - [Link]
Atmel have announced the introduction of the SAMA5D4 to their SAMA5 family of microcontrollers. These use an ARM Cortex A5 core and the new D4 adds H264, VP8 and MPEG4 720p video playback capability at 30fps.
According to Jacko Wilbrink, sr. director of MPUs at Atmel “With the large market acceptance of the Atmel SAMA5D3 Cortex®-A5-based MPUs, we are continuing to shape experiences surrounding the user interface for industrial and consumer applications. The SAMA5D4 enables the addition of video playback to control panels and displays at an unrivalled cost point, security and counterfeiting are becoming growing concerns within the rapidly growing IoT market. These applications require MPUs with advanced encryption while maintaining the same level of high performance. Atmel® | SMART™ SAMA5D4 is positioned to deliver the security and performance many Internet-connected systems require.”
New Processors from Atmel - [Link]
The old resistor decade boxes consisted of a bunch of rotary switches which make them little bulky and expensive. Stynus has built this microcontroller-based resistor decade box that uses one rotary encoder and 16 relay switches to switch on the various resistances. The microcontroller used in this project is PIC16F84A.
PIC Microcontroller based resistor decade box - [Link]
An instructables on motor controllers for cheap robots by JayWeeks
Almost every robot needs to power a motor of some sort or another. Problem is that motors take quite a lot of power, compared to what most microcontrollers operate with. To solve this problem, robots use what is called a motor controller, which usually amounts to some form of electronic switch that can turn on a very high voltage, using a very low one. That’s what we’ll be making today!
Motor controllers for cheap robots - [Link]
xristost blogged about the frequency counter module he made:
First of all I wanted a PIC microcontroller to do the whole job without any additional ICs. Also I wanted to use the the familiar 16F628A, but because one of the portA pins (RA5) can be used only as input I was short of outputs to do the job. Driving 6 digit 7-segment multiplexed display requires 7 + 6 = 13 outputs. The 16F628A has 16 IO pins, two of which are used for the crystal oscillator, one is for the signal input and other one can be used only for input, that leaves us with only 12 useful IO pins. The solution was to drive one of the common cathodes with a transistor, which opens when all other digits are switched off.
Frequency counter with PIC16F628A - [Link]
A fine-spot welder is one of the few equipment where building yourself is cheaper than buying. There are already published a lot of DIY spot welders, this one has some unique features:
It can be used in 2 welding applications: opposed and series configuration.
The construction is kept very simple.
Accurate electrode force adjustment.
It has a solid electrode holder, made of a radiator earthing clamp.
An Arduino microcontroller is used to set the weld time accurately.
Creates a double pulse which improves clamping.
The current can be reduced for welding sensitive parts.
DIY battery tab resistance fine-spot welder - [Link]
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]