Timeline for Cheap load cell and ADS1232 strange oscillation
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 30, 2018 at 11:46 | history | tweeted | twitter.com/StackElectronix/status/1013025922344157184 | ||
| Jun 29, 2018 at 15:34 | vote | accept | cholz | ||
| Jun 28, 2018 at 18:33 | comment | added | D.A.S. | That’s a lot of interference with a drifting clock and aliasing . How stable is your clock? Is it an earth ground PSU? Looks like heavy filtering . Check analog signal with 2 probes in differential mode , calibrated for 0 noise !! | |
| Jun 28, 2018 at 18:04 | answer | added | Elliot Alderson | timeline score: 0 | |
| Jun 28, 2018 at 17:56 | comment | added | cholz | @TonyStewartolderthandirt It is shielded, but not twisted pair. The cabling is only a few feet long. I have about 3000 counts from the adc per lb. | |
| Jun 28, 2018 at 17:52 | comment | added | cholz | @SpehroPefhany The purple line is lightly filtered and the green line is heavily filtered, but neither is the raw data. I should be able to get the raw data on this tomorrow. After this blip in the beginning the lightly filtered line responds as it should to changing loads with no more oscillations like this. | |
| Jun 28, 2018 at 17:48 | comment | added | cholz | @ElliotAlderson The green line is another filter taking its input from the first filter. I don't have the raw data handy but I can experiment with that tomorrow. The scale was turned on within a minute or two of the left edge of the graph. I have added the filter code to the question. | |
| Jun 28, 2018 at 17:46 | history | edited | cholz | CC BY-SA 4.0 |
added 1420 characters in body
|
| Jun 28, 2018 at 15:10 | comment | added | D.A.S. | I suspect 10 sps aliasing with 60Hz | |
| Jun 28, 2018 at 15:02 | comment | added | D.A.S. | How long is your shielded (hopefully) twisted pair? What is 1 lb pk-pk in terms of full scale? Anything with a 1 minute cycle blips followed by a 2 minute cycle then silent is weird since self heating is only 50mW or so | |
| Jun 28, 2018 at 14:28 | comment | added | Spehro 'speff' Pefhany | Is that raw data? Also after it has started, when you change the load, what does the change look like? | |
| Jun 28, 2018 at 13:47 | comment | added | Elliot Alderson | What is the green line in your graph? What does the raw data look like? When do you turn on the scale, at [0] minutes or at the left edge of the graph? What does your code for the filter look like? | |
| Jun 28, 2018 at 13:46 | answer | added | Michael Karas | timeline score: 0 | |
| Jun 28, 2018 at 13:34 | review | First posts | |||
| Jun 28, 2018 at 13:37 | |||||
| Jun 28, 2018 at 13:31 | history | asked | cholz | CC BY-SA 4.0 |