1-Wire Thermometer with LCD
Published in issue 356, July 2006
The present circuit is particularly intended to help the reader in the use of a PIC processor Type PIC16F84, a temperature sensor with 1-Wire protocol Type DS1820 (see), an LCD screen with 2×16 characters (HD44780 compatible) and a light sensor with an LDR that determines whether the background lighting of the LCD should be on.
R1 = LDR (small model)
R3,R5 = 1k
R7 = 3k3
R8 = 10
P1 = 10k preset, horizontal
C1,C2 = 33pF
C3,C4 = 100nF
T1 = BC547
IC1 = PIC16F84A-04CP (programmed, order code 060090-41)
IC2 = 4094
IC3 = DS1820, DS18S20
LCD = alphanumerical LCD, 2x16 characters, 44780-compatible
K1 = 9-way sub-D socket (female), angled, PCB mount
K2 = 3-way SIL pinheader
X1 = 4MHz quartz crystal, parr. cap. 32pF, HC49 case
5 wire links
PCB, ref. 060090-1 from The PCBShop
Click below to download a PDF copy of this article from Elektor magazine.
Please note. In view of the complexity of international markets, Elektor cannot guarantee the availability of components for this project.