I2C EPROM programmer

Sometimes you just need to program I2C EEPROM chips and don want to invest any bucks to it, then you should consider I2C EPROM programmer from https://www.lancos.com site originally designed by Claudio Lanconelli. This is very easy to build and use circuit but it supports 24C01, 24C02, 24C04, 24C08, 24C16 24C32, 24C64, 24C65, 24C128, 24C256, 24C512 I²C Bus EEPROM, auto detects 24XX EEPROM capacity For I2C EPROM programmer you need to download PonyProg programeer software from www.lancos.com .Choose “Easy I2CBus” from the Options – Setup menu and the parallel checkbox on WindowsNT/2000 you have to select “AVR ISP I/O”.

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Serial Peripheral Interface – SPI Bus overview

Serial Peripheral Interface is a simple interface which enables to communicate microcontroller and peripheral chips or intercommunicate between two or more microcontrollers. Serial Peripheral Interface bus sometimes called four wire interface may be used to interface such chips or devices like: LCD, sensors, memories, ADC, RTC. The range of usage is huge. SPI Bus uses synchronous protocol, where transmitting and receiving is guided by clock signal generated by master microcontroller. SPI interface allows connecting several SPI devices while master selects each of them with CS (Chip Select) signal – (Underline means that active is LOW). SPI bus consists of four signal wires: Master Out Slave In (MOSI), Master In Slave Out (MISO), Serial Clock (SCLK or SCK) Chip Select (CS) for the peripheral. Some microcontrollers have a dedicated chip select for SPI interfacing called Slave Select (SS). MOSI signal is generated by master – recipient is Slave. MOSI may also be labeled as SI or SDI. MISO signals are generated by slave. In some chips you might find labels SO or SDO. SCLK or SCK are generated by master to synchronize data transfers. CS (SS) signal is also generated by master to select slave chip or device. Data transfer is…

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7805 voltage regulator for your design

This is most common voltage regulator that is still used in embedded designs. LM7805 voltage regulator is a linear regulator made by several manufacturers like Fairchild, or ST Microelectronics. They can come in several types of packages. For output current up to 1A there may be two types of packages: TO-220 (vertical) and D-PAK (horizontal). With proper heat sink these LM78xx types can handle even more than 1A current. They also have Thermal overload protection, Short circuit protection. If your design won’t exceed 0.1A current you may chose regulator LM78L05 with smaller packages and lower maximum current up to 0.1A. They come in three main types of packages SO-8, SOT-89 and TO-92 Bellow is a table OF all LM78XX regulators and their output Voltages and input voltage ranges. Part Output (V) Input range (V) LM7805 5 7–25 LM7806 6 8–25 LM7808 8 10.5–25 LM7809 9 11.5–25 LM7810 10 12.5–25 LM7812 12 14.5–30 LM7815 15 17.5–30 LM7818 18 21–33 LM7824 24 27–38 Typical Connection is very simple: Couple decoupling capacitors (between 10 uF and 47 uF) are required on the input (V-IN) and output (V-OUT) connected to ground. There are negative voltage regulators that work the same way. They are marked…

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Using VMLAB as virtual oscilloscope

VMLAB is one of well known simulators. This is software simulator of AVR and ST62 microcontrollers. You may download free version of it from https://www.amctools.com. The simulation is far away from real time, but All timings are tied to real world values. VMLAB is designed to work as project. This is a special language (script like), where circuit is described – where are connections between hardware and microcontroller defined. Few prebuilt examples you may find in folders C:\VMLAB\AVR_demo and C:\VMLAB\ WinAVRdemo (If your installation is in C:\VMLAB\ folder). VMLAB is rich in its hardware support: Resistor, Grounded capacitor, Interactive switch / key, LED diode, Pulsed voltage source, Sine wave voltage source, Slider dependent voltage source (interactive), Non-ruturn-to-zero (NRZ) generator (interactive), Operational amplifier, Comparator, 2 inputs NAND gate, 8 bits D to A converter, RS232 based TTY (interactive), LCD module, I2C monitor (interactive), Interactive keypad 4×4 Multiprocess-dedicated: External Input, External Output. So you can do wide range of simulations. VMLAB also has a powerful scope where you can watch voltages on pins or even some internal microcontroller resistor values like ACO, TIMOVF signals. Let’s make simple project using VMLAB tool. Start VMLAB And create new project by selecting Project-New. Select project…

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MoleExpert micro software

The MoleExpert software is a product is based on experiences of many years with the automated analysis of pigmented skin lesions. Essential requirement with this software project was the usefulness of the software with the most different photograph systems. Qualitatively high-quality, evenly and well illuminated top illumination-microscopic pictures of the lesions is the most essential condition for the operability of this software. MoleExpert micro was developed for the support of diagnostic identification. The system spends no diagnosis for this reason, but supplies as results of measurement data to asymmetry, for the delimitation of the lesion, to the color and the size. These parameters of the ABCD rule are recognized for some years as important dermatoscopic parameters. According to a particular algorithm adapted on the image analysis, the four ABCD values are combined into a total core, which can take values between zero to unify. With lesions with high Score, it acts with higher probability around a Melanoma, than with lesions with low Score. Download demo version from here: MoleExpert micro

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Frequency response of discrete system

In previous post we discussed about impulse response. Impulse response h(n) is digital system response in time domain. But there is another characterization of discrete system – frequency response H(ejω). Frequency response can be calculated form impulse response by formula: This means frequency response is systems transfer coefficient to every frequency value. Frequency response is a complex function. So this can be evaluated as:

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