by Warren Miller @ digikey.com:
MCUs are used as the main control element in just about every application imaginable. Their power and flexibility make them the go-to component at the heart of most designs. Since it is important to make sure that your design cannot be easily copied, reverse engineered or tampered with, modern MCUs now provide a few different options for protecting your design; a good understanding of the capabilities and trade-offs are important in order to determine which approach is best for a given design.
This article will review some of the common approaches to design protection, such as making your MCU unreadable from the outside world, using on-chip capabilities to validate that the code to be executed is unmodified, and using external components to provide more advanced security capabilities. On-board techniques for tamper detection and possible “penalties” that can be applied also will be described.
Protect Your MCU Design from Copying and Reverse Engineering - [Link]
This blog post is about my adventures in implementing a stupidly simple way of transferring data over audio to AVR (and why not other embedded chips too), reaching speeds up to 12kbps with really tiny code and memory footprint, using the internal oscillator of Tiny AVR, with hardware parts that cost next to nothing.
12kbps simple audio data transfer for AVR - [Link]
Limpkin has build a development board for the ESP8266-03:
The ESP8266 modules come with a pre-loaded firmware that will accept some commands through their UART interface (connect to wifi, open udp socket, send data to this IP…). Moreover, since Espressif recently released their SDK you can now load your own custom programs using the existing bootloader. To launch this bootloader you just have to connect some IOs to GND in a specific order.
However, anyone wanting to develop a project involving dozens of Wifi nodes has to start from somewhere, eg make a prototype of their future platform. That is why I developed this development board, so the prototyping stage is as simple as possible.
As you can see in the picture below the dev board breaks out all the ESP8266-03 IOs, includes a 3.3V LDO, a USB to UART converter, some logic and a button to automatically start the bootloader.
A development board for the ESP8266-03 - [Link]
Here is another piece of laboratory equipment – LC meter. This type of meter, especially L meter is hard to find in cheap commercial multimeters.
Schematic of this one came from this web page: https://sites.google.com/site/vk3bhr/home/index2-html
It uses PIC microcontroller 16F628A, and because I recently acquired a PIC programmer, I decided to test it with this project. Following the above link you will find the original schematic, PCB, source and HEX files for programing the microcontroller and detailed description.
Simple PIC LC meter - [Link]
Raj @ embedded-lab.com shared his recent project. It’s a mcu controlled dice based on PIC mcu:
Tons of LED dice projects with different output forms have been published online. The most common output configuration in those projects is a 3-1-3 setup (two rows of three LEDs and one LED at in the middle) of seven LEDs, which simulates the actual patterns of dots found on the six faces of a traditional dice. When it is rolled, one or more LEDs are selectively turned on to display a random number between 1 to 6. This project is about a similar LED dice but with a slightly different output form. It uses 6 LEDs which are arranged in a circular pattern and are labeled 1 through 6. They create a chasing effect when the dice is rolled. The chasing effect slows down gradually, and eventually stops at one of the six LEDs. The rolling is done by a gentle shaking of the dice horizontally. The LED dice is powered with a 3V coin cell battery and uses PIC12LF1822 microcontroller to generate a random number and drive the output LEDs.
MCU running LED dice - [Link]
RGB LED disco light is a simple project designed around PIC16F72 microcontroller.
This firmware is a RGB driver, as name suggests it is used to derive or light red, green and blue LEDs in particular fashion. Its main feature is the pattern shown on LEDs. It is quite difficult to describe pattern in words but we want to specify that first it will derive red then green then blue three times and then a particular pattern is shown on LEDs and again the three LEDs light.
RGB LED Disco Lights - [Link]
This project provides some lighting effect by the blinking pattern of the bulbs connected at its output. Up to 8 Bulbs can be connected in between connector CN2 to CN9 and AC power to control them should be connected at Connector CN10. DC Power should be applied at Connector CN11 in accordance with the polarity marked on this connector. Care should be taken while using this it as it contains Main Power on the board.
Microcontroller based running light controller - [Link]
Interfacing a cheap phone camera module to a PIC32 microcontroller – [Link]
Here’s an automatic watering system using AVR from Gadgetronicx:
Primitive irrigation systems possess many drawbacks as it fails to conserve water and human energy. So introducing Automation in it can help us to overcome these drawbacks and pave way to conserve water. This can be done with a simple Soil moisture sensor and a Microcontroller, AVR in our case. You can try out this system to automate watering the plants in your home at affordable cost.
Automatic plant watering system using AVR(Atmega16) Microcontroller - [Link]
An app note (PDF!) from Renesas on how to minimize power consumption when sensing switch inputs
A switch input is one of the simplest interfaces to an MCU. However, when very low power designs are needed the pullup or pulldown resistor for the switch can draw a significant current. If the switch input is a momentary switch the current flow is very short so it is rarely significant. However, if the switch input is a door switch or level sensing switch
or any other switch which may remain in the active state for a relatively long time the energy used must be considered
Most of the discussion that follows gives examples for pull-up devices with the switches, the same principles apply for pull-down components. Also all the discussions assume that the EVdd = Vdd (all ports powered from the same supply voltage).
Minimizing power consumption when sensing switch inputs - [Link]