SD/MMC Card interfacing with Microcontroller Circuit Project

SD/MMC Card interfacing with MUC with AVR Microcontrollers
Interfacing with ATMega 162:

It is easy to interface a MMC (Multimedia Card) with an Atmel ATmega162 (AVR series) via the SPI (Serial Port Interface). The MMC is connected to the SPI pins of the ATmega16 via simple resistor voltage dividers to transform the +5V high levels to about 3.3V used by the MMC. If the Atmega-162 is working on 3.3 V power supply then all the MMC pins can be directly connected to Microcontroller (as in this design). The data-out pin from the MMC goes directly to the ATmega162, because 3.3V is high for the ATmega162 anyway. The schematic of the MMC interfacing is given below.


http://devusb.googlepages.com/sdmmcinterfacing

Microcontroller board with Ethernet, MMC/SD card interface and USB
Hardware components already integrated on the reference design include:
• Atmel ATmega128 RISC microcontroller with standard 10-pin ISP header
• 64 kByte of external SRAM
• USB <-> RS232 interface
• SD/MMC socket
• Ethernet interface with ENC28J60 (IEEE 802.3, 10Base-T)
The hardware design is expandable by connecting additional components to the existing pin header. Several digitial I/Os, A/D inputs as well as the standard SPI and I2C (TWI) serial interfaces are available for user-defined purposes.
The curcuit board is designed as a two-layer board of size 100mm x 80mm. Most components use SMD packages.


http://www.roland-riegel.de/mega-eth/index.html

SD/MMC Interface Integration Guidelines
SD/MMC cards provide a low cost solution for data logging and storage applications
for embedded systems. SD/MMC cards can be easily interfaced with a
Microcontroller using an SPI interface and between one and three control lines. While
the electrical interface is relatively straight forward, successfully implementing a
solution can be time consuming for the initial implementation. This document looks at
some of the common pitfalls encountered. The document assumes the developer is
implementing Brush Electronics SD/MMC File System drivers or Utilities with a
Microchip PIC Microcontroller however the principles apply to other implementations.

http://www.smallridge.com.au/download/SD-MMC%20Integration.pdf


MMC/SD Card interfacing and FAT16 Filesystem with 8051/8052

Content

# Interface to Chan’s Library of functions

# Target development platform

# Setting up the SPI port during startup.A51

# Global type definitions and variables

# Basic SPI function

1. Transferring & Receiving single byte over SPI Bus
2. SPI Chip Select
3. Setting frequency for SPI Clock
4. Sending command to SD Card
5. Reading response from SD Card
6. Delay and Time function

# SD Card Initialization

1. Setting up the card for SPI Communication

# Reading and Writing a single sector

# Working with diskio.c

# Pulling it all together

http://www.8051projects.net/mmc-sd-interface-fat16/MMC-SD-Card-interfacing-and-FAT16-Filesystem.pdf

Infrared motion detector with Microcontroller Circuit

A simple automatic motion-detection Digital Camera Circuit

When the sensor detects movement in a room it will take a burst of
10 photos with the digital camera. Each photo is taken at 0.5sec
interval. After the 10 photos, the camera waits 3 seconds for further
movement and if it is detected, the process is repeated until 80
photos are taken.
The photos can then be downloaded to your PC (via the USB
connection on the board) for viewing.

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The Directional Infrared Detector Module Circuit (DIRM)

Figure shows a block diagram of the DIRM. A Fresnel lens
captures the incident IR and focuses it towards the
pyroelectric sensor increasing the sensitivity of the sensor
and improving its directional response. The resultant signal
passes through a low pass filter, which removes any high
frequency noise generated by mechanical vibration. The
output of the filter is then fed into a differentiator, which
produces an output voltage proportional to the rate of
change of the incident IR. The frequency response of this
differentiator is also rolled off at high frequencies, further
reducing the effects of undesired signals. The window
comparator produces a logic output whenever the rate of
change of incident IR exceeds a given set point.
An 8-bit PIC16F84 microcontroller processes the logic
signals and controls the rotating platform and reports
information to the team leader.

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PIR DETECTOR USING ST7FLITE05 MICROCONTROLLER
A PIR detector can be made easily with ST7FLITE05 using the
circuit shown in Figure. The sensor interfacing circuit (shown on
the left side of the microcontroller in Figure ) can be divided
into the following modules:
1.Transistor circuit used as an amplifier.
2.Transistor biasing controlled through the microcontroller.
3. Software-controlled transistor output.

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Infrared, Alarm, and PIC Microcontroller
OBJECTIVES:
• Get familiar with an infrared emitter diode and receiver.
• Create an obstacle detector with an infrared emitter and receiver.
• Learn about PIC microcontroller and programming a PIC microcontroller.
• Write a PIC program and build the circuit of a household alarm system.

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Ultra-low Power Motion Detection using the MSP430F2013

A system capable of detecting motion using a dual element PIR
sensor is shown in Figure 1 using the MSP430F2013
microcontroller. Using the integrated 16-bit Sigma-Delta
analog-todigital converter and built-in front-end PGA (SD16_A),
the MSP430F2013 provides all the required elements for interfacing
to the PIR sensor in a small footprint. With integrated analog
and a 16MHz, 16-bit RISC CPU, the MSP430F2013 offer a great
deal of processing performance in a small package and at a low cost.

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USB to Microcontroller Interface Circuit

USB to Microcontroller UART Interface Circuit

Figure 7.4 USB to MCU UART Interface
An example of using the FT232R as a USB to Microcontroller
(MCU) UART interface is shown in Figure 7.4. In this application
the FT232R uses TXD and RXD for transmission and reception of
data, and RTS# / CTS# signals for hardware handshaking. Also
in this example CBUS0 has been configured as a 12MHz output to
clock the MCU. Optionally, RI# could be connected to another I/O
pin on the MCU and used to wake up the USB host controller from
suspend mode. If the MCU is handling power management functions,
then a CBUS pin can be configured as PWREN# and would also be
connected to an I/O pin of the MCU.

USB to Microcontroller parallel Interface Circuit

Figure 12 illustrates a typical interface between the FT245BM and
a MicroController ( MCU ). This examples uses two IO Ports of the
MCU, one port ( 8 bits ) to transfer data and the other port ( 4 / 5 bits )
to monitor the TXE# and RFE# status bits and generate the RD# and
WR strobes to the FT245BM as required. Optionally, SI / WU can be
Connected to another IO pin if this function is required. If the SI / WU
function is not required, tie this pin of the FT245M high. If the MCU is
handling power management functions, then PWREN# should also
be connected to an IO pin of the MCU. The 8 data bits of Port 1 can
be shared with other peripherals when the MCU is not accessing the
FT245BM.


FT245BM datasheet pdf


USB from RS-232 UART with Minimal Impact on

PC Software
INTRODUCTION
The RS-232 serial interface is no longer a common port
found on a personal computer (PC). This is a problem
because many embedded applications use the RS-232
interface to communicate with external systems, such as
PCs. A solution is to migrate the application to the
Universal Serial Bus (USB) interface. There are many
different ways to convert an RS-232 interface to USB,
each requiring different levels of expertise. The simplest
method is to emulate RS-232 over the USB bus. An
advantage of this method is the PC application will see
the USB connection as an RS-232 COM connection and
thus, require no changes to the existing software.
Another advantage is this method utilizes a Windows®
driver included with Microsoft® Windows® 98SE and
later versions, making driver development unnecessary.
The objectives of this application note are to explain
some background materials required for a better understanding
of the serial emulation over USB method and
to describe how to migrate an existing application to
USB. A device using the implementation discussed in
this document shall be referred to as a USB RS-232
emulated device. The author assumes that the reader
has some basic knowledge of the USB standard. All
references to the USB specification in this

Continue using COM by Emulating RS-232 over USB

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PIC-USB-4550 PROTOTYPE BOARD FOR PIC18F4550
MICROCONTROLLER WITH USB
INTRODUCTION:
This is handly prototype board for development of USB
application with PIC18F4550 microcontroller. The great all about
it is that if you want only to load code to it i.e. to program it you
can do this without any additional programmer. Microchip provides
these free USB solutions for their microcontrollers which are
available for you to use off the shelf: USB HID Class firmware you
can build mouse or other Himan Interface Device for Windows,
USB CDC Communication class device, USB Mass Storage
firmware - add your own USB disk drives to your computer,
USB-to-RS232 driver. The planty of prototype space allow you easy
to add on sensors, relays and other peripherial devices to interface
to USB. The board can take power from USB or from External supply
with small jumper selection. RESET button, User button and LED
are on-board.

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PIC-USB-STK PIC USB STARTERKIT PROTOTYPE BOARD
FOR PIC18F4550 MICROCONTROLLER WITH USB

INTRODUCTION:
This is starterkit which allow you to explore all capabilities of
PIC18F4550 and the Microchip's USB firmwares. The software
examples include: USB HID mouse which allow you to move the
mouse cursor with the four buttons on the board, USB Mass
storage device on SD-MMC card simple adds USB disk to your
computer, USB to RS232 converter all these firmware under your
control and ready to be customized and embedded in your next
application. The debugging is In-Circuit through ICSP connector,
the free available ports are put on EXTension connector.

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AVR-USB-162 AVR USB AT90USB162 MICROCONTROLLER
PROTOTYPE BOARD WITH USB AND ICSP

AT90USB162 is the easiest way to add USB functionality to your
next device, Atmel provide free open source HID (mouse, keyboard)
and CDC (USB-to-RS232) code and on top of this AT90USB162
cost is same as ATMega16, so what you are waitng for?

AVR-USB-162 board provide the basic circuit necessary to work with

AT90USB162 - USB connector and circuit, external power supply if
your circuit require more power than 100mA which usually USB port
provide, button, status LED, reset button. All AT90USB162 come from
Atmel pre-programmed with bootloader which allow code to be
programmed inside the chip without any external programmer, just
download the FLIP software from Atmel web site and load your HEX
code inside

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Implementation USB into microcontroller: IgorPlug-USB (AVR)

Purpose of this article is to inform readers about implementation
USB interface into singlechip microcontroller, which this interface
directly not supports. Simply: implementation USB interface on
firmware level (similar as emulation of RS232 interface in
microcontrollers, which not have RS232 support). This project
includes development of firmware on microcontroller side, driver
development on computer side (for Windows operating system) ,
development of DLL library for functions calling from another
programs (programmers level) and development of demo program
(users level), which shows all functions of this device. Device is
named IgorPlug-USB (AVR) (as successor of my previous device
for computer remote control IgorPlug - serial port version).

Universal USB interface

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