A I2C controlled, LCD enabled Thermometer: Unterschied zwischen den Versionen
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* current: 12 mA with interrupted connection to the LCD LED | * current: 12 mA with interrupted connection to the LCD LED | ||
* power consumption: 57 mW | * power consumption: 57 mW | ||
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+ | Given that a AA battery has an assumed capacity of 2850 mAh, the thermometer would run for about 50 hours until the batteries are fully discharged. For short-time measurementy upon activation this means at least months of lifetime! | ||
== Images == | == Images == |
Version vom 3. November 2009, 02:19 Uhr
Here's a demonstration of a very tiny Arduino project: It's a microcontroller driven very precise digital thermometer.
Inhaltsverzeichnis
1 Ingredients
- Arduino Mini Pro
- JHD 162A LCD display
- SE95 I2C temperature sensor on a board from Horter & Kalb http://www.horter.de/i2c/index.htm
- 25 kiloOhm Poti
- 1 kiloOhm Poti
- Breadboard
- 3x AA Alkaline cell
Costs:
- Arduino Mini Pro 15€
- JHD 162A LCD display 10€
- SE95 I2C temperature sensor & board 5€
- 25 kiloOhm Poti 0.25 €
- 1 kiloOhm Poti 0.25 €
- Breadboard + jumper cables 10 €
- 3x AA Alkaline cell 2 €
Overall costs: 42.50€
Surely not a very competitive price. But the brain value was immense!
2 Program
Here's the sketch:
#include <Wire.h> #define tmpaddress 0x48 void setup() { Wire.begin(); Serial.begin(1200); } void loop() { // get the temperature Wire.beginTransmission(tmpaddress); Wire.send(0x00); Wire.requestFrom(tmpaddress, 1); int temperature = 0; if (Wire.available()) { temperature = Wire.receive(); } Wire.endTransmission(); Serial.println("-----------"); Serial.println(temperature-3); delay(1000); }
3 Tests
- battery voltage: 4,79 V
- current: 12 mA with interrupted connection to the LCD LED
- power consumption: 57 mW
Given that a AA battery has an assumed capacity of 2850 mAh, the thermometer would run for about 50 hours until the batteries are fully discharged. For short-time measurementy upon activation this means at least months of lifetime!