BaseboardAavikkomursu 7.2

Aavikkomursu

Micro-controller

Extension port for programming microcontroller and sensor input

Resistor

RS485 interface chip for communicating with other devices like computer

RJ-45 connectors for power and communication with other devices like computer

Capasitors for balancing power consumption spikes.

Just put to places where they are close to pins, so we get low inductance and resistance because less wire to the pin -> pin gets correct power.

Wiring

Sensors (/programming unit)

Power + network to other Mursus

Microcontroller

AtTiny841More than just a processor:Has RAM and flash-memory, periferals (like serial communications and analog to digital converters meaning voltage meters)

RS-485 Transceiver

ADM483EARZ:Converts voltage levels to RS-485 standard.Give 1’s and 0’s to it and this one drives correct voltage difference to it’s legs and creates proper signals to RS-485 bus. Voltage difference is then sensed by other chips (in this case communication module and to possible other Mursus).

RS-485 Transceiver

http://www.farnell.com/datasheets/83899.pdf

DI == data in, 0’s and 1’s (~ 0-1,4V ; ~1,4-5V)

RO == read out, 0’s and 1’s (~ 0-0,4V ; ~4-5V)

RE == receive enable (ON when 0 because line on top :P)

DE == data enable (1 -> sends data)In Mursu RE and DE are in same wire, so processor can change state just be using one pin. So, this chip is always in data read or data send mode.

A and B are connected to RS-48 wires, so the communication happends there.

D == driver, transmitter

R == receiver

Programming unit

USB-B connector to computer

Interconnection board to Mursu

Power source and computer communication module

RJ-45 connectors to Mursus

USB cable to computer for electricity and commands / communication

Wiring exampleTo computer for orders and power!

To computer for programming!