21
1 – Wire devices
One of the FM5500 features is realized 1-Wire data protocol, which enables connection of
up to three thermometers (DS1820, DS18S20 and DS18B20) and I-Button
. Figures 9 and
10 show FM5500 and 1-wire devices connection schemes.
Left row of pins
1
3
4
1
2
2
J1
J2
J3
U1
Right row of pins
1W. PWR
(FM5500 – pin3)
1
1W. Data
(FM5500 – pin13)
2
1
Vpp(+5
Volts DC) –
power
source for
external
digital
sensor
GND
(FM5500 – pin1)
3
2
Output
from
external
digital
sensor
Digital Input
4
Figure 9 Digital thermometer DS1820 and TTJ 100 connection scheme
