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Thursday, September 28, 2017

4-digit 7-segment led display thermometer using 1N4148 diode

original version (written in Romanian)

   You can made a cheap thermometer using few components: clone Arduino board (in my case, I use Arduino Nano board with uC ATmega 168, but work with Arduino nano with ATmega328, Arduino Uno, leonardo, etc), a 1N4148 diode, 4-digit 7-segment led display with common cathode or common anode (just few changes in sketch), an breadboard and some wires.
   Schematic is very simple:
  I write first sketch named diode_thermometer_display_1.ino and on dissplay temperature is as integer:
but if it use diode_thermometer_display_2.ino sketch, value is with decimal value:
   I use info from article and I test sketch:
see 1N4148 diode as temperature sensor movie:
   For project with display, I made thermometer with 1N4148 diode as sensor on multiplexed led display
   For understand how can be use a diode as temperature sensor see figure 1 from 1N4148 diode datasheet
and article:
Accurate Temperature Sensing with an External P-N Junction (Linear Technology)