$1.78 USB Power Monitor

13

Comments

  • ercoerco Posts: 19,295
    edited August 2014 Vote Up0Vote Down
    I just tested the $1.78 LED and the fancier $9 OLED version to verify that (besides charging) they both allow a real USB bidirectional connection. I can ID and program a Stamp 2 through them using an FTDI adapter just fine.

    Had to check since I have a few other USB charger cables and goodies that will charge but not pass a USB signal. The charger cable on the Veho speaker, for instance.
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • ercoerco Posts: 19,295
    edited August 2014 Vote Up0Vote Down
    My blue one finally arrived. The LED display on the clear one appears brighter, just because of the blue tint IMO.

    Also won an auction for this different form factor unit for $1.78: http://www.ebay.com/itm/Portable-Mini-USB-Voltage-Current-Detector-Tester-Power-Supply-Charger-Doctor-/390915200276
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,044
    edited August 2014 Vote Up0Vote Down
    'Got mine! (yay, christmas in august) 'Seems to work okay. 'Only bought one, so I don't need to fret over inter-unit discrepencies. :)

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • Duane DegnDuane Degn Posts: 10,002
    edited August 2014 Vote Up0Vote Down
    erco wrote: »
    My blue one finally arrived. The LED display on the clear one appears brighter, just because of the blue tint IMO.

    Having liberated one of the PCBs from its blue enclosure, I can confirm the apparent brightness difference is from the blue plastic.
  • Cluso99Cluso99 Posts: 14,101
    edited August 2014 Vote Up0Vote Down
    Mine arrived yesterday. Works great. Thanks erco!
    Now, what can I fit inside that box???

    BTW Tried it on my external USB SATA HDD - uses 710mA when accessing the HDD.
    My Prop boards: P8XBlade2, RamBlade, CpuBlade, TriBlade
    Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
    Website: www.clusos.com
    Prop Tools (Index) , Emulators (Index) , ZiCog (Z80)
  • ercoerco Posts: 19,295
    edited August 2014 Vote Up0Vote Down
    Cluso99 wrote: »
    Mine arrived yesterday. Works great. Thanks erco!
    Now, what can I fit inside that box???

    More importantly, you're just thirty something posts away from VIP status. What will you do when you wield that much power and awesome responsibility? :)
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Duane DegnDuane Degn Posts: 10,002
    edited August 2014 Vote Up0Vote Down
    My newest monitor not only monitors volts and amps but it also keeps track of Watts, mAh, Watt hours, time running/charging and Joules.

    attachment.php?attachmentid=110717&d=1409376047

    I'm using one of these inexpensive OLED displays plugged directly into the QuickStart. The display is being powered by an I/O pin.

    I'm using a couple of 74HC165 shift registers to capture the multiplexing to the 7-segment display.

    Oh the joy of taking a nice simple gadget and making it horribly complicated.
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  • ercoerco Posts: 19,295
    edited August 2014 Vote Up0Vote Down
    Daddy like! Wow that's quite a contraption!
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • WhitWhit Posts: 3,996
    edited August 2014 Vote Up0Vote Down
    'Got mine! (yay, christmas in august) 'Seems to work okay. 'Only bought one, so I don't need to fret over inter-unit discrepencies.

    @Phil - Good plan! What will you do in December?
    Whit+

    "We keep moving forward, opening new doors, and doing new things, because we're curious and curiosity keeps leading us down new paths." - Walt Disney
  • Duane DegnDuane Degn Posts: 10,002
    edited September 2014 Vote Up0Vote Down
    erco wrote: »
    If you call that living... :)

    Finally, I can start living life. My two meters with OLED displays arrived today. They both work.
  • ercoerco Posts: 19,295
    edited September 2014 Vote Up0Vote Down
    ...and the rest of us can stop holding of breath, so thanks for the update, D-Degn!
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • banjobanjo Posts: 250
    edited September 2014 Vote Up0Vote Down
    Also received my 3 Charger Doctors a couple of days ago. Seem to work ok
    - Thomas Vikstrom (banjo)
    Location: A hop from the longest bridge in...Finland
  • Cluso99Cluso99 Posts: 14,101
    edited September 2014 Vote Up0Vote Down
    erco,
    This little gem is a really neat way to work out power consumption. I have put it on my FPGA board to see how much it is using. ~210mA when loaded with 4 cog P1V.
    My Prop boards: P8XBlade2, RamBlade, CpuBlade, TriBlade
    Prop OS (also see Sphinx, PropDos, PropCmd, Spinix)
    Website: www.clusos.com
    Prop Tools (Index) , Emulators (Index) , ZiCog (Z80)
  • ercoerco Posts: 19,295
    edited September 2014 Vote Up0Vote Down
    This gizmo might also be useful as a general purpose (not 5V USB only) power monitor since the specs say: Workable range: 3.5 - 7.0V, 0 - 3A.

    Put one on your power supply or Boebot to monitor battery voltage & current use. Duane hacked his into that Quickstart contraption, but it looks like he's still using it as a 5V monitor. I got some extras, might be time to hack one open.

    Especially since they're down to $1.61 now. :)

    http://www.ebay.com/itm/USB-Charger-Doctor-Mobile-Battery-Tester-Power-Detector-Voltage-Current-Meter-SR-/301268582455
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,044
    edited September 2014 Vote Up0Vote Down
    I really do wish it were possible to follow the money on one of these items. IOW, who's making a profit, who's taking it in the shorts, and who's subsidizing the whole affair, from manufacturing, to sales, to shipping? Heck, by the time I buy a PCB-mountable USB-A connector from DigiKey, more than half of that $1.61 budget is spent.

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • RDL2004RDL2004 Posts: 2,554
    edited September 2014 Vote Up0Vote Down
    The $1.61 price isn't even enough to cover postage if you wanted to mail one to a friend, so obviously the USPS is taking a loss. The Chinese government is probably covering the shipping on the other end.

    The parts are likely to be mostly QC rejects or 3rd shift specials, very cheap but not free. The seller might be making as much as 50 cents profit. PayPal and eBay are getting their cut, you can be sure of that.

    The buyer gets a piece of cheap electronics junk that, if they're lucky, won't damage their computer and whatever is plugged into it when it eventually fails.
    - Rick
  • Duane DegnDuane Degn Posts: 10,002
    edited September 2014 Vote Up0Vote Down
    RDL2004 wrote: »
    The $1.61 price isn't even enough to cover postage if you wanted to mail one to a friend, so obviously the USPS is taking a loss.

    I don't follow? I have a hard time believing the USPS is shipping these at a loss. For what possible reason would they do this?

    I can believe the Chinese government is subsidizing the shipping.
  • xanaduxanadu Posts: 3,240
    edited September 2014 Vote Up0Vote Down
    I don't really know, it's magic. USPS has to move it from the dock or airport to the delivery address. For some rural areas that might create a loss but probably balances out in denser areas.

    I found some info on ePacket - https://www.usps.com/ship/commercial-epacket.htm

    Edit: Maybe the foreign government pays USPS directly through the ePacket program and it's never added to the transaction.
  • RDL2004RDL2004 Posts: 2,554
    edited September 2014 Vote Up0Vote Down
    I don't understand what's magic or hard to follow about it.

    Buy an item for $2 or less on eBay, one that's too big for a letter size envelope. Wait 2 weeks or so for it to arrive. It will be delivered by the United States Post Office. Now, take that package back to the Post Office and mail it to somebody - anybody, anywhere. Come back here and let us know how much postage you had to pay.

    I've seen a number of different explanations for this discrepancy. I've never believed any of them to be completely correct.

    Even though the USPS is surely losing money on this, it probably doesn't amount to much. I once asked the mail man how much stuff he delivered that looked like it came from China and he said "not much". Apparently, the vast majority of mail these days is domestic packages and the bulk rate advertising stuff.
    - Rick
  • Duane DegnDuane Degn Posts: 10,002
    edited September 2014 Vote Up0Vote Down
    RDL2004 wrote: »
    I don't understand what's magic or hard to follow about it.

    Buy an item for $2 or less on eBay, one that's too big for a letter size envelope. Wait 2 weeks or so for it to arrive. It will be delivered by the United States Post Office. Now, take that package back to the Post Office and mail it to somebody - anybody, anywhere. Come back here and let us know how much postage you had to pay.

    I've seen a number of different explanations for this discrepancy. I've never believed any of them to be completely correct.

    Even though the USPS is surely losing money on this, it probably doesn't amount to much. I once asked the mail man how much stuff he delivered that looked like it came from China and he said "not much". Apparently, the vast majority of mail these days is domestic packages and the bulk rate advertising stuff.

    Let me know if this correctly summarizes your argument:

    "It costs us more to send the item than the ebay seller is paying to send it, therefore USPS is shipping it at a loss."

    Is that a fair summary? If so, I think you're using seriously flawed logic. I'm willing to elaborate why if you'd like.

    BTW, while I'm disagreeing with you, I'm hoping I'm not doing it in a disagreeable way.
  • User NameUser Name Posts: 1,451
    edited September 2014 Vote Up0Vote Down
    My understanding was that USPS doesn't get paid a single cent to deliver international mail. But when I send a package from the US to the UK, USPS keeps all the postage and the Royal Mail gets nothing. It's some sort of international agreement that presumes 'it all comes out in the wash.'
    Platåberget
  • Duane DegnDuane Degn Posts: 10,002
    edited September 2014 Vote Up0Vote Down
    User Name wrote: »
    My understanding was that USPS doesn't get paid a single cent to deliver international mail. But when I send a package from the US to the UK, USPS keeps all the postage and the Royal Mail gets nothing. It's some sort of international agreement that presumes 'it all comes out in the wash.'

    That would explain a lot.

    I just don't see how the US sends nearly as much stuff to China as China sends here.
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 22,044
    edited September 2014 Vote Up0Vote Down
    User Name wrote:
    My understanding was that USPS doesn't get paid a single cent to deliver international mail.

    That used to be true, but it's not anymore. From this article:
    "Since 1969, countries have been required to pay terminal dues to destination countries as compensation for local delivery costs. In general, they settle on the exact amounts every quarter based on both weight and number of items shipped. (Before this system took hold, countries just assumed that mail volumes were about balanced.)"

    -Phil
    “Perfection is achieved not when there is nothing more to add, but when there is nothing left to take away. -Antoine de Saint-Exupery
  • ercoerco Posts: 19,295
    edited September 2014 Vote Up0Vote Down
    Duane Degn wrote: »
    I just don't see how the US sends nearly as much stuff to China as China sends here.

    I'll stop posting erco's daily deals if it will help equalize the trade imbalance. Then you cats will have your full weekly allowance to spend on beer, cable TV, and similar self-improvement thingies. :)
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • ercoerco Posts: 19,295
    edited October 2014 Vote Up0Vote Down
    Just had to beat Duane with this full house. 7 USB monitors, 3 different types represented.

    Now I can give them to my EE pals and die happy.

    attachment.php?attachmentid=111275&d=1412386591
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    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • ercoerco Posts: 19,295
    edited January 2015 Vote Up0Vote Down
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • Duane DegnDuane Degn Posts: 10,002
    edited January 2015 Vote Up0Vote Down
    erco wrote: »

    This YouTube video has just about got me convinced the meter is worth the price.

    Seeing all the many features included in the device, got me thinking about ways I could improve my QuickStart addon I show in post #68. I'd think it should be possible to add some calibration features to the QuickStart board which would greatly increase its accuracy of the displayed data. The QuickStart could also provide nice graphs of the charge data.

    While I think it's possible to make a nice little charge meter by combining the cheap USB meter with a QuickStart and OLED display, I doubt I'll put the effort into doing this.

    Seeing the graphing feature on the USB meter did get me thinking about projects which could benefit from graphed data on a small OLED display. I'll need to figure out what kind of data I should graph with my aluminum wallet project.
  • TorTor Posts: 1,956
    edited January 2015 Vote Up0Vote Down
    It looks quite good. Lots of features. The only weak spot seems to be the USB connector at one end, as was pointed out in the video.

    However, I'm not sure I would need all of those features all the time.. in that sense $33 is a little bit too much. I'm thinking that what I would find nearly as useful would be a kind of (cheaper) breakout thingy which you could connect in-between USB ports the same way, and have access to a measure point for voltage and a jumper where you could insert your amp meter. I have lots of digital volt/amp meters..
  • ercoerco Posts: 19,295
    edited January 2015 Vote Up0Vote Down
    You did see the original post, Tor?
    "When you make a thing, a thing that is new, it is so complicated making it that it is bound to be ugly. But those that make it after you, they don’t have to worry about making it. And they can make it pretty, and so everybody can like it when others make it after you."

    - Pablo Picasso
  • TorTor Posts: 1,956
    edited January 2015 Vote Up0Vote Down
    You mean the first post, the $1.78 USB power monitor? If so, yes, and I even bought a few.. but I was thinking about the USB3.0 capable one (plug is different), which can handle much more current as well. The $33 device looks great, but isn't cheap. That's where a USB3.0 "breakout" adapter came to mind - just give me the harness, and I'll supply the metering. Must be cheaper I think.
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