{"id":7332,"date":"2013-04-12T23:27:59","date_gmt":"2013-04-13T03:27:59","guid":{"rendered":"http:\/\/embedded-lab.com\/blog\/?p=7332"},"modified":"2013-04-12T23:34:17","modified_gmt":"2013-04-13T03:34:17","slug":"mcp9802-temperature-sensor-and-arduino","status":"publish","type":"post","link":"https:\/\/embedded-lab.com\/blog\/mcp9802-temperature-sensor-and-arduino\/","title":{"rendered":"MCP9802 temperature sensor and Arduino"},"content":{"rendered":"

MCP9802<\/a><\/strong> is a digital temperature sensor from Microchip that measures temperatures between -55\u00b0C and +125\u00b0C to a digital word. It provides an accuracy of \u00b11\u00b0C (maximum) from -10\u00b0C to +85\u00b0C. The MCP9802 sensor comes with user-programmable registers that provide flexibility for temperature sensing applications. The register settings also allow user-selectable 9-bit to 12-bit temperature measurement resolution. This sensor has an industry standard 2-wire I2C compatible serial interface, allowing up to eight devices to be controlled in a single serial bus. In this blog post I am going to write about an Arduino sketch to interface the MCP9802 sensor with an Arduino for temperature sensing application. For illustration, I am using the MCP9802 sensor onboard the I2C EEPROM+Sensor breakout board<\/a><\/strong>.<\/p>\n

\"\"<\/a>

Arduino and MCP9802<\/p><\/div>
\n
\nThe hardware connections between MCP9802 and Arduino is straightforward. Two pull-up resistors are required on the I2C signal lines. On Arduino Uno, the I2C lines are multiplexed with analog pins A4 (SDA) and A5 (SCL).<\/p>\n

\"\"<\/a>

Hardare connections between MCP9802 and Arduino<\/p><\/div>\n

The following Arduino sketch configures the MCP9802 sensor resolution to 12-bit. The Arduino receives the temperature bytes and sends them out to serial port. The values are received and displayed on the serial monitor window on PC. Note that the 7-bit slave addresses of the
\nMCP9802 sensor on board is 0\u00d748.<\/p>\n\n

#include <Wire.h><\/span>\n \n#define address 0x48   \/\/I2C address of MCP9802<\/span>\n#define baudrate 9600  \/\/ Baud rate for serial communication <\/span>\nint<\/span> TempByte1,<\/span> TempByte2;<\/span>\n \nvoid<\/span> setup(<\/span>)<\/span>\n{<\/span>\nWire.begin<\/span>(<\/span>)<\/span>;<\/span>\nSerial.begin<\/span>(<\/span>baudrate)<\/span>;<\/span>\n \n\/\/ Write to Configuration Register <\/span>\nWire.beginTransmission<\/span>(<\/span>address)<\/span>;<\/span>\nWire.write<\/span>(<\/span>0x01<\/span>)<\/span>;<\/span>  \/\/ Address to Configuration register<\/span>\nWire.write<\/span>(<\/span>0x64<\/span>)<\/span>;<\/span>  \/\/ ADC resolution: 12-bit,<\/span>\nWire.endTransmission<\/span>(<\/span>)<\/span>;<\/span>\n}<\/span>\n \n \nvoid<\/span> loop(<\/span>)<\/span>\n{<\/span>\n \n\/\/ Read temperature <\/span>\nWire.beginTransmission<\/span>(<\/span>address)<\/span>;<\/span>\nWire.write<\/span>(<\/span>(<\/span>byte)<\/span>0x00<\/span>)<\/span>;<\/span>    \/\/ Pointer to temperature register<\/span>\nWire.endTransmission<\/span>(<\/span>)<\/span>;<\/span>\n \nWire.beginTransmission<\/span>(<\/span>address)<\/span>;<\/span>\nWire.requestFrom<\/span>(<\/span>address,<\/span> 2<\/span>)<\/span>;<\/span>  \/\/ Now read two bytes of temperature data<\/span>\nif<\/span> (<\/span>Wire.available<\/span>(<\/span>)<\/span>)<\/span> {<\/span>\n  TempByte1 =<\/span> Wire.read<\/span>(<\/span>)<\/span>;<\/span>\n  TempByte2 =<\/span> Wire.read<\/span>(<\/span>)<\/span>;<\/span>\n \n  int<\/span> Temperature =<\/span> (<\/span>(<\/span>TempByte1 <<<\/span> 8<\/span>)<\/span> |<\/span> TempByte2)<\/span>;<\/span>\n  Temperature =<\/span> Temperature >><\/span> 4<\/span>;<\/span>\n  float<\/span> TempC =<\/span> 1.0<\/span>*<\/span>Temperature*<\/span>0.0625<\/span>;<\/span>\n  float<\/span> TempF =<\/span> TempC*<\/span>1.8<\/span>+<\/span>32.0<\/span>;<\/span>\n  Serial.print<\/span>(<\/span>" Temperature= "<\/span>)<\/span>;<\/span>\n  Serial.print<\/span>(<\/span>TempC)<\/span>;<\/span>\n  Serial.print<\/span>(<\/span>" C, "<\/span>)<\/span>;<\/span>\n  Serial.print<\/span>(<\/span>TempF)<\/span>;<\/span>\n  Serial.println<\/span>(<\/span>" F"<\/span>)<\/span>;<\/span>\n}<\/span>\nelse<\/span>{<\/span>\n  Serial.println<\/span>(<\/span>"No response "<\/span>)<\/span>;<\/span>\n}<\/span>\nWire.endTransmission<\/span>(<\/span>)<\/span>;<\/span>\ndelay(<\/span>1000<\/span>)<\/span>;<\/span>\n}<\/span><\/pre><\/td><\/tr><\/table><\/div>\n\n
\"\"<\/a>
Temperature readings displayed on Serial Monitor terminal window<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"
MCP9802 is a digital temperature sensor from Microchip that measures temperatures between -55\u00b0C and +125\u00b0C to a digital word. It provides an accuracy of \u00b11\u00b0C (maximum) from -10\u00b0C to +85\u00b0C. The MCP9802 sensor comes with user-programmable registers that provide flexibility for temperature sensing applications. The register settings also allow user-selectable 9-bit to 12-bit temperature measurement resolution. This sensor has an industry standard 2-wire I2C compatible serial interface, allowing up to eight devices to be controlled in a single serial bus. In this blog post I am going to write about an Arduino sketch to interface the MCP9802 sensor with an<\/p>\n","protected":false},"author":1,"featured_media":7351,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[150,245],"tags":[148,549,102],"class_list":["post-7332","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-arduino-2","category-embedded-lab-projects","tag-arduino","tag-mcp9802","tag-temperature-sensor"],"_links":{"self":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/7332","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/comments?post=7332"}],"version-history":[{"count":10,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/7332\/revisions"}],"predecessor-version":[{"id":7360,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/posts\/7332\/revisions\/7360"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media\/7351"}],"wp:attachment":[{"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/media?parent=7332"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/categories?post=7332"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/embedded-lab.com\/blog\/wp-json\/wp\/v2\/tags?post=7332"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}