Temperature - MCP9803
Temperature 1 - I2C - MCP9803
Fig. 1 I2C Temperature Sensor 1
Description:
This is a temperature sensor, with an I2C interface. It is based around a Microchip MCP9803 sensor.
It is a high accuracy sensor with resolution selectable between 9 and 12 bits. It can generate an interrupt if the temperature goes beyond programmed limits.
The board can be powered from 2.7 to 5V processor board.
Specifications:
Input voltage 2.7 to 5V
InterfaceI2C
Temperature-55 to +125 °C
Resolution9 to 12 bits
0.5 to 0.0625 °C
Schematic:
The SDA and SCK I2C lines are pulled high by R2 and R3, while R7 and R8 protects the lines. R4 to R6 pull address line A0 to A2 low. The lines can be pulled high by SW1, and can be used to set the I2C slave address of the board.
The Alert signal is open drain, and is pulled high by R1. SW1 allows to pass the signal to the interrupt signal of the I2C bus connector.
The I2C connectors JP1and JP2 allow the board to be connected to an I2C bus in a chain. They are optional, to keep cost down, and the board can be connected by soldering cables directly on it.
Fig. 2 I2C Temperature 1 sensor schematic
Construction:
The PCB fits on a small single sided board. All components are on the top side except the temperature sensor.
Fig. 3 I2C Temperature 1 sensor layout
Start with the wire link on the topo side, below the capacitor, then the lowest components, and continue with the higher ones. I keep the bottom side (copper side) component for last.
| I2C Temperature 1 Sensor Component list |
|---|
| C1: 100 nF R1, R4, R5, R6: 100 K R2, R3: 22 K R7, R8: 220 IC1: Microchip MCP9803 SOIC SW1: microswitch DIP8 K1, K2: Connector AMP MT 5pins male |
How to use / Testing:
To check the board, connect the board to an I2C interface, and run the I2C Temperature tutorial. Just make sure you set the right I2C slave address with SW1.
Files and links:
Eagle PCB and schematics files for I2C Temperature sensor 1.PDFs of PCB, layout and schematics of I2C Temperature sensor 1.
PIC Tutorials for I2C Temperature sensor.
Microchip MCP9803 Temperature sensor.