Board Features - OLIMEX MOD-IO User Manual

INTRODUCTION

BOARD FEATURES

Downloaded from Elcodis.com electronic components distributor
MOD-IO is a small but powerful development board who let you control 4
optoisolated input and 4 relay outputs - with this features is possible to turn on
and off almost any electronic device at home. The board has UEXT_FEMALE
connector which allows you to communicate with a PC and UEXT_MALE
connector where you can connect other Olimex board with UEXT.
The MOD-IO project is fully open software and open hardware. The customer has
full access to the documentation of the board including schematics and board
design.
The main idea of MOD-IO chain connection is to extend:
- isolated relay outputs
- isolated digit inputs
- non isolated analog inputs
- non isolated digit inputs/outputs
using UEXT male/female connector. So the MCU interfaces (I2C, SPI, UART) from
all chain boards are connected in parallel.
Note that if you want to connect more than 1 MOD-IO board then on the interface
bus (I2C or UART or SPI) has to have only one Master device. The other devices
have to be Slaves.
For example: if UART interface is used - the master will send a string with Slave
address and command. All Slaves will listen UART bus through RXD line while
all Slave TXD lines are inputs. So when the address is recognized from the Slave
device, the one will answer as it will force TXD pin like output but immediately
after command answer is finished the Slave TXD pin must be initialized like input.
The same principle can be used for other interfaces (SPI or I2C).
Microcontroller: Atmega16L
–
AVRISP connector
–
JTAG connector
–
EXT connector
–
UEXT_MALE
–
UEXT_FEMALE
–
Clock circuit
–
User button
–
Reset circuit and button
–
Power Jack
–
Power-on led
–
Nine status leds
–
Four optocoupler isolated inputs
–
Page 2