{"id":196,"date":"2017-05-06T15:55:48","date_gmt":"2017-05-06T20:55:48","guid":{"rendered":"http:\/\/www.millamilla.com\/?p=196"},"modified":"2017-05-27T17:00:31","modified_gmt":"2017-05-27T22:00:31","slug":"testing-mcp9808-with-bus-pirate","status":"publish","type":"post","link":"https:\/\/www.millamilla.com:443\/?p=196","title":{"rendered":"Testing MCP9808 with Bus Pirate"},"content":{"rendered":"

As part of the CE Header project from the\u00a0CE Skills<\/a>\u00a0course , I picked an additional temp sensor to test with, the MCP9808<\/a>. \u00a0I used a Bus Pirate<\/a>\u00a0(Dangerous Prototypes) and probes, from Seeed Studio<\/a>, to iteratively poke at it until I understood how to talk to it via I2C.<\/p>\n

Once I soldered the MCP9808 to a small carrier board from Adafruit<\/a>, I placed it on a breadboard and wired it up to the Bus Pirate. \u00a0Please note, the cable and connectors in the image below are from the Seeed probe cable. \u00a0Some of the other probe cables have the colors in a different order on the connectors.<\/p>\n

I used putty<\/a> to connect to the Bus Pirate via a mini usb cable.<\/p>\n\n\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\n<\/tr>\n<\/thead>\n
Initalize the Bus Pirate<\/caption>\n
m 4 1<\/td>\nMode, I2C, Speed 5khz<\/td>\n<\/tr>\n
W<\/td>\nTurn power on<\/td>\n<\/tr>\n
P<\/td>\nTurn on pull ups<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Find the\u00a0I2C address<\/caption>\n
(1)<\/td>\nFind the slave address<\/td>\n0x30(0x18 W) 0x31(0x18 R)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Working with the Config register<\/caption>\n
[ 0x30 0x01 [ 0x31 r:2 ]<\/td>\nRead the register<\/td>\n0x00 (default)<\/td>\n<\/tr>\n
[ 0x30 0x01 0x00 0x08 ]<\/td>\nEnable Alert Stat<\/td>\n<\/td>\n<\/tr>\n
[ 0x30 0x01 0x00 0x08 [ 0x31 r:2 ]<\/td>\nEnable Alert Stat and read back current config<\/td>\n\u00a00x00\u00a00x08<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

 <\/p>\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Working with the\u00a0Manufacturer register<\/caption>\n
[ 0x30 0x06 [ 0x31 r:2 ]<\/td>\nRead the register<\/td>\n0x00 0x54 \u00a0(default)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Working with the Device register<\/caption>\n
[ 0x30 0x07 [ 0x31 r:2 ]<\/td>\nRead the register<\/td>\n0x04 0x00\u00a0 (default)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Working with the Resolution register<\/caption>\n
[ 0x30 0x08 [ 0x31 r:1]<\/td>\nRead the register<\/td>\n0x03\u00a0 (default)<\/td>\n<\/tr>\n
[ 0x30 0x08 0x00 [ 0x31 r:1]<\/td>\nSet register to 0x00 or 1 bit resolution and read back<\/td>\n0x03<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n\n\n\n\n\n\n
Command<\/td>\nWhat it does<\/td>\nOutput<\/td>\n<\/tr>\n<\/thead>\n
Working with the Ambient temperature register<\/caption>\n
[ 0x30 0x05 [ 0x31 r:2 ]<\/td>\nRead the register<\/td>\nex:\u00a00xC1 0xBC<\/p>\n

Celsius = (C1BC & FFF)\/16 = 24C or 75F, see P25 of MCP9808 Datasheet<\/td>\n<\/tr>\n

Special result values<\/p>\n

0x80 0x00,\u00a0TA>TCRIT
\n0x40 0x00,\u00a0TA>TUPPER
\n0x20 0x00,\u00a0TA<TLOWER
\n0x10 0xBE ( after upper&1F ), TA < 0C, Celsius = d256 – ((( 10 & 0F ) * d16) + (BE\/d16))= -245?<\/td>\n

<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

\"\"<\/a>

Click image for full size<\/p><\/div>\n

 <\/p>\n","protected":false},"excerpt":{"rendered":"

As part of the CE Header project from the\u00a0CE Skills\u00a0course , I picked an additional temp sensor to test with, the MCP9808. \u00a0I used a Bus Pirate\u00a0(Dangerous Prototypes) and probes, from Seeed Studio, to iteratively poke at it until I understood how to talk to it via I2C. Once I soldered the MCP9808 to a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-196","post","type-post","status-publish","format-standard","hentry","category-contextual-electronics"],"_links":{"self":[{"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts\/196","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=196"}],"version-history":[{"count":15,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts\/196\/revisions"}],"predecessor-version":[{"id":257,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts\/196\/revisions\/257"}],"wp:attachment":[{"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=196"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=196"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=196"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}