Tweet-a-watt calibration issues

[ChrisCrewdson]

I am having trouble getting reasonable numbers out of my Tweet-a-watt. I have checked and double checked the wiring, set the SP to 1F4 (5 seconds), and tried swapping the D0 and D4 to triple-check if I still got it wrong somehow. I have a version with the SMD style 2902 like http://forums.adafruit.com/viewtopic.php?f=40&t=11009

The issue is that that with nothing plugged into it, I get numbers like:

Code: Select all

1       Current draw, in amperes: 1.68121442125
        Watt draw, in VA: 185.825426945
                Wh used in last  5.03800010681  seconds:  0.260052366888
1       Current draw, in amperes: 1.82163187856
        Watt draw, in VA: 231.738140417
                Wh used in last  5.03900003433  seconds:  0.324369027089
1       Current draw, in amperes: 1.67741935484
        Watt draw, in VA: 191.567362429
                Wh used in last  5.02199983597  seconds:  0.banned
1       Current draw, in amperes: 1.33965844402
        Watt draw, in VA: 150.406072106
                Wh used in last  5.03700017929  seconds:  0.210443170046
1       Current draw, in amperes: 1.25996204934
        Watt draw, in VA: 148.884250474
                Wh used in last  5.03899979591  seconds:  0.208396585488
1       Current draw, in amperes: 1.36622390892
        Watt draw, in VA: 146.0
                Wh used in last  5.02200007439  seconds:  0.203670003017

As you can see, the amperage draw seems to jump around by half an amp, and the Watt draw jumps +/- 100 watts.

The display of the KaW shows very accurate numbers. I tried a few different light bulb wattages just to check. The LCD display flickered a little at a 2 second SP, but with 5 it seems to stay solid.

I tried EnergyLogger too, and I couldn't get it to zero, no matter how I calibrated it.

Any suggestions?

[ChrisCrewdson]

Just as some additional info, here's some debug output with a vrefcalibration of 492:

Code: Select all

<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[778, -1, -1, -1, 483, -1
], [812, -1, -1, -1, 485, -1], [809, -1, -1, -1, 485, -1], [717, -1, -1, -1, 480
, -1], [563, -1, -1, -1, 472, -1], [380, -1, -1, -1, 464, -1], [217, -1, -1, -1,
456, -1], [90, -1, -1, -1, 446, -1], [64, -1, -1, -1, 439, -1], [123, -1, -1, -
1, 440, -1], [244, -1, -1, -1, 452, -1], [424, -1, -1, -1, 468, -1], [625, -1, -
1, -1, 485, -1], [756, -1, -1, -1, 485, -1], [798, -1, -1, -1, 486, -1], [795, -
1, -1, -1, 485, -1], [791, -1, -1, -1, 482, -1], [670, -1, -1, -1, 476, -1], [49
3, -1, -1, -1, 468, -1]]}>
ampdata: [485, 485, 480, 472, 464, 456, 446, 439, 440, 452, 468, 485, 485, 486,
485, 482, 476, 468]
voltdata: [812, 809, 717, 563, 380, 217, 90, 64, 123, 244, 424, 625, 756, 798, 7
95, 791, 670, 493]
1       Current draw, in amperes: 1.43453510436
        Watt draw, in VA: 166.69829222
                Wh used in last  5.03600001335  seconds:  0.233192389402
<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[634, -1, -1, -1, 483, -1
], [815, -1, -1, -1, 489, -1], [807, -1, -1, -1, 486, -1], [803, -1, -1, -1, 485
, -1], [717, -1, -1, -1, 479, -1], [538, -1, -1, -1, 470, -1], [340, -1, -1, -1,
461, -1], [200, -1, -1, -1, 452, -1], [90, -1, -1, -1, 445, -1], [64, -1, -1, -
1, 438, -1], [137, -1, -1, -1, 441, -1], [280, -1, -1, -1, 452, -1], [476, -1, -
1, -1, 474, -1], [643, -1, -1, -1, 485, -1], [770, -1, -1, -1, 486, -1], [791, -
1, -1, -1, 485, -1], [788, -1, -1, -1, 485, -1], [744, -1, -1, -1, 479, -1], [60
8, -1, -1, -1, 470, -1]]}>
ampdata: [489, 486, 485, 479, 470, 461, 452, 445, 438, 441, 452, 474, 485, 486,
485, 485, 479, 470]
voltdata: [815, 807, 803, 717, 538, 340, 200, 90, 64, 137, 280, 476, 643, 770, 7
91, 788, 744, 608]
1       Current draw, in amperes: 1.41176470588
        Watt draw, in VA: 164.557874763
                Wh used in last  5.03999996185  seconds:  0.230381022924
<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[816, -1, -1, -1, 487, -1
], [811, -1, -1, -1, 488, -1], [765, -1, -1, -1, 482, -1], [623, -1, -1, -1, 475
, -1], [434, -1, -1, -1, 468, -1], [282, -1, -1, -1, 460, -1], [147, -1, -1, -1,
450, -1], [74, -1, -1, -1, 444, -1], [69, -1, -1, -1, 437, -1], [170, -1, -1, -
1, 445, -1], [329, -1, -1, -1, 458, -1], [554, -1, -1, -1, 481, -1], [700, -1, -
1, -1, 485, -1], [799, -1, -1, -1, 485, -1], [797, -1, -1, -1, 485, -1], [793, -
1, -1, -1, 485, -1], [714, -1, -1, -1, 478, -1], [530, -1, -1, -1, 469, -1], [35
5, -1, -1, -1, 461, -1]]}>
ampdata: [488, 482, 475, 468, 460, 450, 444, 437, 445, 458, 481, 485, 485, 485,
485, 478, 469, 461]
voltdata: [811, 765, 623, 434, 282, 147, 74, 69, 170, 329, 554, 700, 799, 797, 7
93, 714, 530, 355]
1       Current draw, in amperes: 1.47628083491
        Watt draw, in VA: 167.510436433
                Wh used in last  5.03699994087  seconds:  0.234375016224
<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[747, -1, -1, -1, 483, -1
], [813, -1, -1, -1, 488, -1], [804, -1, -1, -1, 485, -1], [740, -1, -1, -1, 481
, -1], [600, -1, -1, -1, 473, -1], [411, -1, -1, -1, 465, -1], [258, -1, -1, -1,
455, -1], [119, -1, -1, -1, 448, -1], [66, -1, -1, -1, 440, -1], [96, -1, -1, -
1, 435, -1], [216, -1, -1, -1, 446, -1], [381, -1, -1, -1, 464, -1], [595, -1, -
1, -1, 483, -1], [747, -1, -1, -1, 485, -1], [793, -1, -1, -1, 485, -1], [790, -
1, -1, -1, 485, -1], [786, -1, -1, -1, 483, -1], [676, -1, -1, -1, 473, -1], [47
9, -1, -1, -1, 466, -1]]}>
ampdata: [488, 485, 481, 473, 465, 455, 448, 440, 435, 446, 464, 483, 485, 485,
485, 483, 473, 466]
voltdata: [813, 804, 740, 600, 411, 258, 119, 66, 96, 216, 381, 595, 747, 793, 7
90, 786, 676, 479]
1       Current draw, in amperes: 1.48007590133
        Watt draw, in VA: 171.24857685
                Wh used in last  5.05200004578  seconds:  0.240318838357
<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[636, -1, -1, -1, 486, -1
], [805, -1, -1, -1, 489, -1], [803, -1, -1, -1, 485, -1], [798, -1, -1, -1, 484
, -1], [730, -1, -1, -1, 478, -1], [584, -1, -1, -1, 470, -1], [396, -1, -1, -1,
463, -1], [247, -1, -1, -1, 455, -1], [111, -1, -1, -1, 446, -1], [63, -1, -1,
-1, 438, -1], [105, -1, -1, -1, 437, -1], [225, -1, -1, -1, 447, -1], [395, -1,
-1, -1, 464, -1], [584, -1, -1, -1, 481, -1], [740, -1, -1, -1, 485, -1], [788,
-1, -1, -1, 485, -1], [785, -1, -1, -1, 485, -1], [782, -1, -1, -1, 481, -1], [6
84, -1, -1, -1, 474, -1]]}>
ampdata: [489, 485, 484, 478, 470, 463, 455, 446, 438, 437, 447, 464, 481, 485,
485, 485, 481, 474]
voltdata: [805, 803, 798, 730, 584, 396, 247, 111, 63, 105, 225, 395, 584, 740,
788, 785, 782, 684]
1       Current draw, in amperes: 1.48387096774
        Watt draw, in VA: 170.796963947
                Wh used in last  5.03699994087  seconds:  0.238973415917
<xbee {app_id: 0x83, address_16: 1, rssi: 49, address_broadcast: False, pan_broa
dcast: False, total_samples: 19, digital: [[-1, -1, -1, -1, -1, -1, -1, -1, -1],
[-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1
, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1
, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1
, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1
, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1
, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1
, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1
, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1], [-1, -1, -1, -1, -1, -1, -1, -1
, -1], [-1, -1, -1, -1, -1, -1, -1, -1, -1]], analog: [[671, -1, -1, -1, 487, -1
], [816, -1, -1, -1, 488, -1], [808, -1, -1, -1, 485, -1], [803, -1, -1, -1, 484
, -1], [699, -1, -1, -1, 477, -1], [536, -1, -1, -1, 470, -1], [359, -1, -1, -1,
462, -1], [200, -1, -1, -1, 453, -1], [84, -1, -1, -1, 444, -1], [65, -1, -1, -
1, 437, -1], [137, -1, -1, -1, 440, -1], [261, -1, -1, -1, 451, -1], [450, -1, -
1, -1, 470, -1], [642, -1, -1, -1, 485, -1], [786, -1, -1, -1, 485, -1], [793, -
1, -1, -1, 485, -1], [789, -1, -1, -1, 485, -1], [759, -1, -1, -1, 480, -1], [60
6, -1, -1, -1, 470, -1]]}>
ampdata: [488, 485, 484, 477, 470, 462, 453, 444, 437, 440, 451, 470, 485, 485,
485, 485, 480, 470]
voltdata: [816, 808, 803, 699, 536, 359, 200, 84, 65, 137, 261, 450, 642, 786, 7
93, 789, 759, 606]
1       Current draw, in amperes: 1.45351043643
        Watt draw, in VA: 169.426944972
                Wh used in last  5.04200005531  seconds:  0.237291851644

[adafruit]

could be that outlet is very 'dirty'? do you have other outlets you can try?

[ChrisCrewdson]

It is possible, yes.
I will try to plug it into a line conditioner and my UPS tonight to see if that make a difference. I did try a couple of different plug circuits in my house.

[ChrisCrewdson]

Ah... I forgot I did try this and it did not help. I will have to dig this project out and try again now that I have moved to a new house.