May 2008 - Do It Easy With ScienceProg

Safety Protection Guides and Fact about Microcontroller You Should Know

Microcontrollers are widely used in nowadays electronic and modern devices. You can track them whether for personal use for fun or even for serious and confidential applications by banks, security services, government authority, or the military field. Most of the algorithm that uploaded into its memory is well written in Assembler. Many villains out there want to hack or attack the microcontroller, maybe just for fun or for their own purposes (some of them willing to hack and sell the top-secret from companies for profitable) To reduce the risk of being attack by these microcontroller hackers, that is why we must know the types of attack categories.

Microcontroller Development tools on USB stick

Looking for compact but flexible, simple, and cheap development board? You should consider this nice list of microcontroller USB-Stick tools. These are special development tools that include all necessary hardware and software in a portable USB stick. Most of them consist of two parts – a USB stick and attachable target board. For instance, eZ430-RF2500 is the world’s smallest low-power wireless development tool. At only $49, the device includes a USB emulator to program and debug your application in-system and two 2.4-GHz wireless target boards featuring the highly integrated MSP430F2274 ultra-low-power MCU.

Voltage references in embedded design

Embedded systems that are dealing with DAC require good voltage references. Despite all voltage references having their nominal values, specific tolerances indicate how much values can vary from the nominal value. References, as a rule, are semiconductors that characteristics are affected by temperature. For instance, if we decide to use a 2.5V voltage reference then (Zener) diode LM336A-2.5 may be a good choice for this. These diodes have a low-temperature coefficient. It can guarantee that voltage will be in the range between 2.44 and 2.54 at 25ºC. This precise Zener diode has a third lead that can be used to adjust break down voltage. In the following figure, you may see a diode with a potentiometer where breakdown voltage can be adjusted in the range of ±120mV:

Yet Another Simple AVR ISP cable

Probably this programmer cable can be found on every AVR fan website. It is straightforward and easy to build. You need a few passive components that can be packed inside the LPT connector. From my perspective, I wouldn’t recommend using this one ISP programmer if you are more serious about microcontroller projects because it has poor computer port protection. It connects directly to the LPT port without precautions. I recommend using a similar ISP circuit with buffer IC between LPT and target board. But let’s don’t pretend like we are brilliant. The whole beauty is in its simplicity. This thing does its job perfectly as long as the target board power supply is OK.