Author Topic: EEVblog #1241 - Power Up Display Counter Project - Part 1  (Read 1875 times)

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Offline ipscell

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Re: EEVblog #1241 - Power Up Display Counter Project - Part 1
« Reply #25 on: August 31, 2019, 07:30:03 am »
Found this e-ink display on Taobao. Claimed to work down to 2.3V. I think this could be better compared to a segment because it allows smaller size and easier MCU interfacing.
https://item.taobao.com/item.htm?spm=a230r.1.14.130.56721a21xd94y2&id=588912154396&ns=1&abbucket=20#detail

Search query: 电子墨显示

Also what do you think about mechanical counters like this one? Just plug a motor into it and make it stop after 1 revolution. You can even 3D print these and get any size and digit number.
« Last Edit: August 31, 2019, 11:27:28 am by ipscell »
 

Online westfw

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Re: EEVblog #1241 - Power Up Display Counter Project - Part 1
« Reply #26 on: August 31, 2019, 10:10:00 pm »
Quote
Bistable ChLCD. Seems like a good alternative to e-ink and memory LCD.
Whatever happened to cholesteric liquid crystal displays, anyway?  (these will retain an image with zero power; exactly the sort of thing Dave is looking for.)  I remember "Kent Displays" showing up at trade shows touting the technology, and it's "low cost manufacturing on flexible substrates", but Kent seems to have become a consumer products company ("BoogieBoard"), and it doesn't look like the tech has passed on to anyone else (or at least, it hasn't shown up in the mass market) :-(IIRC, driving the chLCD was a bit problematic, but I didn't think it was worse than ePaper.  I recall several "simple" displays being sold (batter gauge with a couple of digits and a bar graph, etc.)
 

Online Fungus

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Re: EEVblog #1241 - Power Up Display Counter Project - Part 1
« Reply #27 on: September 01, 2019, 01:41:32 am »
Also what do you think about mechanical counters like this one? Just plug a motor into it and make it stop after 1 revolution. You can even 3D print these and get any size and digit number.

There's also those mechanical counters they put in arcade machines to count the coins:

Just send them a voltage pulse and they tick up by one. Zero power needed to maintain the display between pulses.
« Last Edit: September 01, 2019, 01:47:24 pm by Fungus »
 
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Offline Twoflower

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Re: EEVblog #1241 - Power Up Display Counter Project - Part 1
« Reply #28 on: September 01, 2019, 12:48:10 pm »
By the way the still active 6 digit e-ink display (SCB721001 at Digikey, Pinout) should not be soldered down, but use a connector (https://www.te.com/usa-en/product-5-1734592-0.html). The same goes probably for most of the flex ribbons that show up. I don't think they're supposed do be soldered at all.

Still there's little how to actually drive it. But probably like described in chapter 6 here from a different display.
 
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Offline RFZ

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Re: EEVblog #1241 - Power Up Display Counter Project - Part 1
« Reply #29 on: September 08, 2019, 03:31:52 pm »
Hey,
I accidentally came across a category of products that actually use very small low power 7 segment digits: OTP Security Cards
These are usually credit-card style or actual credit-cards that integrate a small ePaper display to show OTP or other access tokens.
Examples can be found here: https://www.smartdisplayer.com/products
These manufacturers also implement custom OTP algorithms and different form factors.

I also came across a video of someone who made his own ePaper display (not the one linked few posts before, but pretty similar). It's really just creating the electrodes on a PCB and bonding a ePaper display foil on top. So I guess making your own or ordering small quantities of custom displays from china is not that expensive.

Btw: Something that wasn't mentioned in the Video at all is the fact that ePaper Displays take a long time to update. Do you somehow want to make sure that the display always updates correctly? You may need a buffer cap to ensure the update finishes in case the product is powered up for a second or less...
 


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