{"id":225,"date":"2017-05-06T16:53:51","date_gmt":"2017-05-06T21:53:51","guid":{"rendered":"http:\/\/www.millamilla.com\/?p=225"},"modified":"2017-05-27T17:00:50","modified_gmt":"2017-05-27T22:00:50","slug":"testing-ds7505-with-bus-pirate","status":"publish","type":"post","link":"https:\/\/www.millamilla.com:443\/?p=225","title":{"rendered":"Testing DS7505 with Bus Pirate"},"content":{"rendered":"

As part of the CE Header project from the\u00a0CE Skills<\/a>\u00a0course , I needed to learn to work with\u00a0DS7505<\/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 DS7505\u00a0to 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>\n0x90(0x48 W) 0x91(0x48 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
[ 0x90 0x01 [ 0x91 r:1 ]<\/td>\nRead the register<\/td>\n0x00 (default)<\/td>\n<\/tr>\n
[ 0x90 0x01 0x60 ]<\/td>\nEnable 12 bit resolution<\/td>\n<\/td>\n<\/tr>\n
[ 0x90 0x01 0x60 [ 0x91 r:1 ]<\/td>\nEnable 12 bit resolution and read back current config<\/td>\n\u00a00x60<\/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 temperature register<\/caption>\n
[ 0x90 0x00 [ 0x91 r:2 ]<\/td>\nRead the register<\/td>\nex:\u00a0 0x19 0xE0<\/td>\n<\/tr>\n
 <\/p>\n

How to calculate given: 0x19 0xE0 and 12 bit resolution.<\/p>\n

Bit 8 of MSB is the sign. 0=+ and 1=-
\nMSB is whole number
\nLSB is fraction<\/p>\n

The most significant 4 bits of the LSB are used for 12bit precision.<\/td>\n

MSB 0011001
\n25C +
\nTotal = 25.75C<\/td>\n		LSB 1100000
\n12\/16=.75<\/td>\n<\/tr>\n
Given: 0xE6 0x78<\/p>\n

Note: negative due to the 8th bit of the MSB being 1<\/td>\n

MSB 11100110
\n(NOT 11100110) +1
\n00011001 + 1
\n00011010
\n-26C +
\nTotal = -25.0625C<\/td>\n		LSB\u00a01111000<\/p>\n

15\/16=.9375<\/p>\n

0.9375<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

 <\/p>\n

\"\"<\/a>

Click 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 needed to learn to work with\u00a0DS7505. \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 DS7505\u00a0to a small carrier board from Adafruit, […]<\/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-225","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\/225","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=225"}],"version-history":[{"count":4,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts\/225\/revisions"}],"predecessor-version":[{"id":258,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=\/wp\/v2\/posts\/225\/revisions\/258"}],"wp:attachment":[{"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=225"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=225"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.millamilla.com:443\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=225"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}