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jebem · (This post was last modified: 08-20-2015 05:46 PM by jebem.)

You may know this information from the 41 architecture here in the HP Journal, partially covering the display multiplexing system as well.
I put it here just in case.

Also, the quick start guide contains the full 7-bit char set here.

EdS2 · 08-20-2015, 03:00 PM

It would be good if a custom LCD turns out to be practical and reasonable cost.

But just in case it isn't, I was wondering if an e-ink display would work well. Here's one for $35 which is 46x22mm active area, 200x96 pixels. A bit small, perhaps?

Chris Chung · 08-20-2015, 03:41 PM

Thanks all, the architecture article pointed by Jebem is extremely valuable to me, it gave the viewing angle for the display and other useful information.

I will pursue a quotation assuming the glass is about 70mm wide for now. If someone can take a crude measure WxH for me it would be great.

@EdS2, never play w/ e-ink and it also looks pricy. I have a small sharp memory display which I will find time and make a demo to show you.

thanks.

rwiker · (This post was last modified: 08-23-2015 09:07 PM by rwiker.)

[attachment=2450]

(08-19-2015 05:19 PM)Chris Chung Wrote: I kind of verify that the MCU will be able to handle all the segment and can do 6-MUX (or 8-MUX).

Now I am working on the physicals for the custom glass so that I can send information and ask for an actual quote.

I need to ask the community for help.

1. locate a photo / drawing of the display w/ all the segments on, especially all the icons (PGM, USER, ALPHA, etc), I found one drawing on the digits and I noticed the very specific (non-coherent) segments.

2. exact dimension of an actual display, including thickness.

3. what will be the preference if we are to order the custom LCD
a. same size as original. (good geometry, more usability)
b. smaller than original. (will shrink the whole thing, nice for a little hand-away gift)
c. larger than original. (not likely, I think)
* not sure how it will impact cost, I would think not a lot.

Thanks.

Here's a photo that shows most of the annunciators; the only one missing (I think) is the "BAT" annunciator.

[Image: IMG_0137.JPG?raw=1]

Chris Chung · 08-21-2015, 12:32 PM

(08-20-2015 06:10 PM)rwiker Wrote: Here's a photo that shows most of the annunciators; the only one missing (I think) is the "BAT" annunciator.

Your link does not seem to work.

Anyway, one factory came back to me. Yes you can get the tooling for $900. But for the size of our glass, the MOQ is 2000. They didn't even bother to continue as I indicated that I need 100 for an initial batch. Anyway, I will try others. We might end up w/ a less desirable "option" of going dot matrix.

jebem · 08-21-2015, 02:52 PM

(08-21-2015 12:32 PM)Chris Chung Wrote: Anyway, one factory came back to me. Yes you can get the tooling for $900. But for the size of our glass, the MOQ is 2000. They didn't even bother to continue as I indicated that I need 100 for an initial batch. Anyway, I will try others. We might end up w/ a less desirable "option" of going dot matrix.

Yap, 2000 is way too much, at least for this forum members.
I hope to be wrong, but I even doubt that there are 100 interested members here from the start, considering the responses to this thread so far.
I know many people are in vacancies and others will only show interest when they see the actual product up and running.
So in the end, getting 100 interested members is a number that can be reached during the life span of this project.

Standard dot matrix lcd is just fine with me, but this will create a new challenge as one will need to design the 7-bit character set font bit maps from scratch replicating the original 41 symbols.

rwiker · 08-23-2015, 09:12 PM

(08-21-2015 12:32 PM)Chris Chung Wrote:
(08-20-2015 06:10 PM)rwiker Wrote: Here's a photo that shows most of the annunciators; the only one missing (I think) is the "BAT" annunciator.

Your link does not seem to work.

Sorry about that - link fixed (hopefully).

rtoi · 08-24-2015, 02:13 PM

I know it is a longshot, but I had to post: DIY LCD. https://www.youtube.com/watch?v=_zoeeR3geTA

jjohnson873 · 08-24-2015, 11:31 PM

I know this is a long shot, but anyone think of asking HP of who they used for the HP-41C LCD glass vendor? Perhaps the original vendor still can reproduce the same glass with the 14 segment digits along with the same annunciators. Just a thought. I always hate reinventing the wheel.

Chris Chung · 08-25-2015, 07:02 PM

(08-21-2015 02:52 PM)jebem Wrote:
(08-21-2015 12:32 PM)Chris Chung Wrote: Anyway, one factory came back to me. Yes you can get the tooling for $900. But for the size of our glass, the MOQ is 2000. They didn't even bother to continue as I indicated that I need 100 for an initial batch. Anyway, I will try others. We might end up w/ a less desirable "option" of going dot matrix.

Yap, 2000 is way too much, at least for this forum members.
I hope to be wrong, but I even doubt that there are 100 interested members here from the start, considering the responses to this thread so far.
I know many people are in vacancies and others will only show interest when they see the actual product up and running.
So in the end, getting 100 interested members is a number that can be reached during the life span of this project.

Standard dot matrix lcd is just fine with me, but this will create a new challenge as one will need to design the 7-bit character set font bit maps from scratch replicating the original 41 symbols.

Another factory did not reply after I stated that the 1st batch is only 100 units.
Does not look promising.

I am trying another route. I will continue to look for a cheap enough factory for custom glass. And I will start to build a standalone unit w/ 128x32ish COG types. The bitmaps shouldn't be to hard to do. I might use a lesser device as no LCD segment driving is needed.

@rtoi, @rwiker, @jjohnson873, thanks for links and input.

Sylvain Cote · 08-26-2015, 02:06 AM

Count me in for your first batch! 8-)
Sylvain

Chris Chung · 08-26-2015, 01:45 PM

(08-26-2015 02:06 AM)Sylvain Cote Wrote: Count me in for your first batch! 8-)
Sylvain

You mean the dot matrix version? It is many months away. Unlike NP-25, I am starting from scratch this time.

. ordered a COG glass for 1st prototype. 3-4 weeks
. create a "shield" w/ perfboard (buttons, display, battery). 1 week
. develop / test / migrate crude firmware on TI LaunchPad w/ shield. 1 week

* ready to design custom PCB, order more parts..... 5-6 weeks before standalone unit appears.

jch · 08-26-2015, 07:58 PM

(08-26-2015 01:45 PM)Chris Chung Wrote: . ordered a COG glass for 1st prototype. 3-4 weeks

Somethink like This ?

Jean-Christophe

Chris Chung · 08-27-2015, 12:47 AM

(08-26-2015 07:58 PM)jch Wrote:
(08-26-2015 01:45 PM)Chris Chung Wrote: . ordered a COG glass for 1st prototype. 3-4 weeks

Somethink like This ?

Jean-Christophe

Yes. I believe I got the OEM version though. Mine is coming from Aliexpress (<$10 shipped). It has the same pinout, dimensions, ST7565R controller. The DOGM is similarly priced, but when I get it from newark, mouser, digikey and the like, it will cost me +$20 Fedex shipping. So yeah, I will wait for 3 weeks.

The size is good as the width is 2mm less than the width of my LaunchPad. Will make a nice stackable shield for prototyping.

Benoit Maag · 08-29-2015, 12:23 AM

Chris,

just an idea: do you think one of the big component distributors (I guess I am not allowed to quote names here) might be interested in joining you for a 2,000 pc order of such displays? After all, they have access to a worldwide market and may be confident they can sell 2,000 HP-41C type displays. One of these distributors also has a project club - this may be a good platform to promote the display and projects made with it, possibly including your new HP-41C?

Benoit

d b · (This post was last modified: 08-29-2015 05:45 AM by d b.)

(08-29-2015 12:23 AM)Benoit Maag Wrote: Chris,

just an idea: do you think one of the big component distributors (I guess I am not allowed to quote names here) might be interested in joining you for a 2,000 pc order of such displays? After all, they have access to a worldwide market and may be confident they can sell 2,000 HP-41C type displays. One of these distributors also has a project club - this may be a good platform to promote the display and projects made with it, possibly including your new HP-41C?

Benoit

Ben;

Don't worry about naming names of any supply companies. You creative types need that info so you can make our favorite toys. There's no way that any one person can know all the sources, or even all the products.

The closest we here have come to a prohibition like that was a years-ago request on the old forum that anyone mentioning an ebay auction should admit that it's his, &/or give his ebay handle. Now days the classified section asks only that we keep the beating of our own drums within the bounds of good taste.

Your post was welcome information. That project club of their's is an intriguing idea.

Waon Shinyoe · (This post was last modified: 08-31-2015 02:19 AM by Waon Shinyoe.)

Hi Chris,

I'm so interested in your project. For the custom glass, I and Zweb did some research and found that it should not be that expensive! We made an inquiry on taobao and got to know that...

The set-up cost (with several samples) is only 600 RMB! (a little bit less than 100 USD)

We offered the following information:

The dimension: about 66.3 mm x 15 mm. (I did not open my 41C , so it is the size of the upper protective plastic. But it should be close.)

The graph:

Massimo Gnerucci · 08-31-2015, 05:37 AM

(08-31-2015 01:18 AM)Waon Shinyoe Wrote: The graph:

Excellent news Waon!

And thank you for the picture: I knew I had it somewhere, but wasn't able to find it.

Waon Shinyoe · 08-31-2015, 11:46 AM

Further info:

The 600 yuan set-up cost is from a company which requires a minimum order quantity of 5000.

According to another company, the set-up cost is 1200 yuan with a minimum order quantity of 500. Unit price is about 7 yuan. (The unit price is just an estimate since the company needs to do the design and drawing to see the actual cost... and you have to pay the set-up cost first to know the accurate unit price XD)

Chris Chung · 08-31-2015, 01:16 PM

(08-29-2015 12:23 AM)Benoit Maag Wrote: Chris,

just an idea: do you think one of the big component distributors (I guess I am not allowed to quote names here) might be interested in joining you for a 2,000 pc order of such displays? After all, they have access to a worldwide market and may be confident they can sell 2,000 HP-41C type displays. One of these distributors also has a project club - this may be a good platform to promote the display and projects made with it, possibly including your new HP-41C?

Benoit

I would doubt it be possible on such a specific glass. You won't even find the more generic glass that goes on evaluation boards (like the Launchpad I used in the mock-up video). And those distributors can't deal w/ a hobbyist like myself.

One thought will be to pair w/ the DIY shops, seeedstudio, elecrow that can works w/ designers to sell kits, etc. Not sure how much risk they can take on similar projects, but I shall try this as an option. Thanks.

(08-31-2015 11:46 AM)Waon Shinyoe Wrote: Further info:

The 600 yuan set-up cost is from a company which requires a minimum order quantity of 5000.

According to another company, the set-up cost is 1200 yuan with a minimum order quantity of 500. Unit price is about 7 yuan. (The unit price is just an estimate since the company needs to do the design and drawing to see the actual cost... and you have to pay the set-up cost first to know the accurate unit price XD)

Yes, I also saw offers from Taobao that boasts very low tooling cost, and lower MOQ. Taobao offers are way lower than Aliexpress offers and payment is an issue though. Most shops requires the chinese version of paypal (zhifubao or their bank alliance card / account) to do business.

In the end, for the handful I had contacted, the advertised offers are the "best case" scenario for a job. I.e. static or 4-mux (simple routes), "watch" size design (little ink, little glass), zebra contacts (no pin cost).

I am not ready to try Taobao sellers as they are mostly setup for local Chinese shoppers and I will need some kind of proxy which sounds trouble for custom projects.

I understand the process and related cost for a custom product and I won't imagine it could be done for a few hundred dollars. What I think I can afford is up to US$1k all around, tooling + whatever number of units (say 50+) that lands w/ it. I think it may be reasonable / doable for some smaller factories but not the larger ones (you can see their average transaction of $10,000+ in their alibaba profiles)

If anyone is in Shenzhen and be able to advise please do so. In the meantime I am continuing w/ the COG version while poking some more small LCD glass manufacturers and hope they are of the right setup for this.

Thanks and good to hear inputs from everyone.