{"id":1663,"date":"2024-08-27T17:16:50","date_gmt":"2024-08-28T00:16:50","guid":{"rendered":"https:\/\/unixwizardry.com\/?p=1663"},"modified":"2024-08-27T17:28:58","modified_gmt":"2024-08-28T00:28:58","slug":"another-temporary-issue-and-delay","status":"publish","type":"post","link":"https:\/\/unixwizardry.com\/index.php\/2024\/08\/27\/another-temporary-issue-and-delay\/","title":{"rendered":"Another Perplexing Temporary Issue and Delay"},"content":{"rendered":"\t\t
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During testing of a new modification I added, MOSFET power control to bring down the weather station standby current, everything was looking great until I monkeyed around with the 1-Wire rain gauge counter and the windvane.\u00a0 (I completed the 1-wire counter retrofit, BTW, more on that later.)\u00a0 All I wanted to do was add header pin connectors to both device’s cables and run the MetOne weather station code (and as the saying goes: “All I wanted to do was drain the swamp and then I found myself up to my ass in alligators”).\u00a0 Upon reconnecting my newly completed and soldered 1-wire counter module (new post coming forthwith), the debug output was going crazy trying to find any 1-Wire devices.\u00a0 Like…huh?!?\u00a0 This WAS working before.\u00a0<\/p>

Here’s what was going on from output from PlatformIO:\u00a0<\/p>

Checking for I2C devices…:<\/em><\/span>
Checking for 1-Wire devices…<\/em><\/span>
There are devices present on 1-Wire bus<\/em><\/span><\/p>

Searching 1-Wire bus with OWSearch()…<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }<\/em><\/span>
Calculated CRC of device serial is 0<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80 }<\/em><\/span>
Calculated CRC of device serial is 0<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40 }<\/em><\/span>
Calculated CRC of device serial is 0<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC0 }<\/em><\/span>
Calculated CRC of device serial is 0<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20 }<\/em><\/span>
Calculated CRC of device serial is 0<\/em><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xA0 }<\/em><\/span>
… (it doesn’t ever stop!)<\/strong><\/em><\/p>

Great.\u00a0 Now I have to delve back into the 1-Wire search algorithm to find out what the hell is going on. \ud83d\ude41\u00a0 \u00a0 So, I loaded up a KNOWN WORKING code and ran that.\u00a0 Same thing!!\u00a0 And I tried another one I had, and it showed the same output.\u00a0 Now my mind is totally blown – what happened?!?\u00a0 Was it the DS2482??\u00a0 This has me really bummed out – thought I was on the home stretch finally, especially now when (according to Seattle standards, anyway), a monster lightning storm moved through and dumped a TON of rain.\u00a0 And me with non-working rain gauge now. \ud83d\ude41<\/p>

As it turns out this was probably good thing that I found this now.\u00a0 The problem was that the 1-Wire bus was shorted to ground (on my breadboard), and I didn’t test for the SD (short detected) bit in the DS2482’s status register.\u00a0 Now I’m going to fix that and update my DS248X 1-wire library.\u00a0 (Interesting that other DS2482 libraries didn’t catch this as well.)\u00a0 \"\" Considering the kind of rat’s nest of jumpers, maybe it’s a small wonder that it didn’t happen before.\u00a0 Those white wires are connected to ground common to set the DS2482 address.\u00a0 I need more black jumpers apparently to make it more obvious.<\/p>

So, I added some debugging info showing the bit status of the DS2482 status register to the OWReset() function.\u00a0 This function tests for a “Presence Pulse” from ANY 1-Wire devices on the bus or whether the bus is shorted.\u00a0 Here is some output from my test:<\/p>

\u00a0 \u00a0 \u00a0 \u00a0 \u00a0DS2482 Status Register bit definitions:<\/em><\/span><\/p>

\u00a0 \u00a0 \u00a0bit7\u00a0 \u00a0 bit6\u00a0 \u00a0bit5\u00a0 \u00a0 bit4\u00a0 \u00a0bit3\u00a0 \u00a0bit2\u00a0 bit1\u00a0 \u00a0bit0<\/em><\/div>
\u00a0 \u00a0 \u00a0DIR\u00a0 \u00a0TSB\u00a0 \u00a0SBR\u00a0 \u00a0RST \u00a0 LL\u00a0 \u00a0 \u00a0SD\u00a0 \u00a0PPD \u00a01WB<\/em><\/div>
\u00a0 \u00a0 \u00a0 \u00a0\\\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \\\u00a0 \u00a0 \u00a0 \\<\/div>
\u00a0 \u00a0 Direction\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0\\\u00a0 \u00a0 Presence Pulse Detected<\/div>
\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \\<\/div>
\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0Short Detected<\/div><\/div>

Checking for 1-Wire devices…<\/span>
Status Register: 10101010<\/span><\/p>

There are devices present on 1-Wire bus<\/span><\/p>

Searching 1-Wire bus with OWSearch()…<\/span>
Status Register: 10101010<\/span>
Found device: { 0x10, 0x67, 0xBB, 0xE0, 0x02, 0x08, 0x00, 0xF2 }<\/span><\/strong>
Calculated CRC of device serial is F2<\/span><\/strong>
This device is a 1-wire thermometer<\/span><\/strong>
Status Register: 10101010<\/span>
Status Register: 10101010 <– Normal<\/em><\/span><\/span>
Found device: { 0x12, 0x05, 0x1C, 0x22, 0x00, 0x00, 0x00, 0x40 }<\/span><\/strong>
Calculated CRC of device serial is 40<\/span><\/strong>
Status Register: 01001010 <– Normal<\/em><\/span><\/span>
Found device: { 0x1D, 0x97, 0x87, 0x01, 0x00, 0x00, 0x00, 0xE2 }<\/span><\/strong>
Calculated CRC of device serial is E2<\/span><\/strong>
Found 1-wire counter at { 0x1D, 0x97, 0x87, 0x01, 0x00, 0x00, 0x00, 0xE2 }<\/span><\/strong>
Status Register: 10101010<\/span>
Status Register: 10101010 <– Normal<\/em><\/span><\/span>
DS2423 returned: 0<\/span><\/p>

Checking for I2C devices…:<\/span>
Checking for 1-Wire devices…<\/span>
Status Register: 10100110<\/span>
There are devices present on 1-Wire bus<\/span>
Searching 1-Wire bus with OWSearch()…<\/span>
Status Register: 10100110\u00a0 \u00a0 \u00a0 <– weird… SD bit (bit 2) set AND Presence Pulse (bit 1) (??)<\/em><\/span><\/span><\/p>

Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }<\/span>
Calculated CRC of device serial is 0<\/span>
Status Register: 00000110\u00a0 \u00a0 <– weird… SD bit (bit 2) set AND Presence Pulse (bit 1) (??)<\/em><\/span><\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80 }<\/span>
Calculated CRC of device serial is 0<\/span>
Status Register: 10000110<\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40 }<\/span>
Calculated CRC of device serial is 0<\/span>
Status Register: 00000110<\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xC0 }<\/span>
Calculated CRC of device serial is 0<\/span>
Status Register: 10000110<\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x20 }<\/span>
Calculated CRC of device serial is 0<\/span>
Status Register: 00000110<\/span>
Found device: { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xA0 }<\/span>
Calculated CRC of device serial is 0<\/span><\/p>

In each case when the short is detected (SD bit set) the presence pulse (PPD) is also set.\u00a0 I don’t understand that-it’s not supposed to be set when SD is set.\u00a0 Very odd.\u00a0 Anyway, now to fix the library and the weather station code.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t","protected":false},"excerpt":{"rendered":"

During testing of a new modification I added, MOSFET power control to bring down the weather station standby current, everything was looking […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[35,38],"tags":[],"class_list":["post-1663","post","type-post","status-publish","format-standard","hentry","category-programming","category-weather-instruments"],"_links":{"self":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/1663","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/comments?post=1663"}],"version-history":[{"count":73,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/1663\/revisions"}],"predecessor-version":[{"id":1745,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/posts\/1663\/revisions\/1745"}],"wp:attachment":[{"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/media?parent=1663"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/categories?post=1663"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/unixwizardry.com\/index.php\/wp-json\/wp\/v2\/tags?post=1663"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}