Arduino enclosure, LCD shield, keypad launched on kickstarter - Page 1
Forum section: electronics / general

author: tim48v
author_rank: Newbie
timestamp: March 05, 2015, 07:58:03 pm
content: Everyone,Here's the link to our kickstarter project.https://www.kickstarter.com/projects/638976489/enclosure-lcd-keypad-elk-expansion-shield-for-ardiPlease forward to every geek you know.

author: Kean
author_rank: Unknown
timestamp: March 06, 2015, 06:52:26 am
content: I sent a comment to Tim via Kickstarter, but thought I'd copy it hereQuoteNow I think about it, they're probably using a "bare glass" LCD which needs specific drive signals, and the STM8 variant they've used probably has an LCD driver. Not sure if there is an Arduino compatible micro that has an LCD driver built in, but a small text or graphical LCD would be much more flexible (although also more expensive). My other comments are specific to my typical small quantity project build requirements, which I imagine arent' unique.

author: tim48v
author_rank: Newbie
timestamp: March 06, 2015, 08:11:28 pm
content: You are correct, we needed an LCD driver for the bare glass LCD and the STM8 is much cheaper than the Atmega169. It is flash programmable and someone could reflash it if desired (the pins will be on the board.)That's a good idea regarding the 4 extra keys: layout the board so they could be added to the matrix. That would take only 1 more pin and the co-processor could handle it.We plan to have some prototype room available on the board, you could add the LTC2950 there.Thanks for the feedback.Tim

author: SL4P
author_rank: Super Contributor
timestamp: March 06, 2015, 08:48:15 pm
content: I'd forego the decicated BACKLIGHT button...Leave it as an unlabelled or 'FUNC' button.Backlight should time out after nn secs of inactivity (configurable in SW to stay on or delayed fade)First keypress from 'idle' state turns on the backlight until another timeout or other event.I've done this s a lot, and it looks and feels natural.If you put this keypad / display functionality in a pre-packaged library - you might also put a 'dim' PWM level in there - so the backlight is not completely 'off' in the dark! Then user can find the unit on his wall or desk - and it wakes up when they press any button!Cheers - nice idea.P.S - to take it a step further. (...also done in the past)Mylar keypads are too expensive for small-runs, and the multi-layer (seven- if I recall) with switches and overlay / window masks etc ... all require artwork and fabrication...Provide an option for low-profile mechanical SMT buttons.The proto and low-volume market will be appreciative.Make the button board with as many positions as possible in the available space, and the plastic case half-way punched forallof them. Then a simple 2-layer mylar label defines the actual legends needed by the end-user application - and you rarely run out of buttons! (navigation diamonds etc)Good luck! It can be done!

author: tim48v
author_rank: Newbie
timestamp: March 07, 2015, 03:14:48 am
content: Cost of a graphical LCD was the first concern. Second, even a 128x64 lcd has 8K pixels. That can put a load on memory and the processor.For many applications, the old fashioned 7 segment display is the easiest to read and by far the simplest to write code for.

author: tim48v
author_rank: Newbie
timestamp: March 07, 2015, 03:20:38 am
content: Regarding the backlight for the LCD: it's controlled by a pwm under software control. The "backlight" button you see in the example photos are on a custom keypad we did for a specific project.The production version won't have a dedicated backlight key; see attached pdf.

author: sleemanj
author_rank: Super Contributor
timestamp: March 07, 2015, 03:55:16 am
content: Quote from: tim48v on March 07, 2015, 03:20:38 amSo who thought it was a good idea to make the big first image on the page be of NOT the product you are making? This campaign is a bit confused I think.It seems too specialised to me - for general purpose prototyping which is what you are trying to aim at - especially given the LCD segment display.Really would be much better with either a pixel display, or a good old character LCD, a small-size one you can probably get 4x16 in there, then you can dispense with the co-pro, just have an I2C bus expander.The pre-printed button labels would annoy me, I don't want my "start" and "stop" buttons labelled "F1" and "F2" etc..Many moons ago there was a games "console" called a Tunix (in NZ, in the US it's the Emerson Arcadia), it had controllers with a membrane numeric keypad built into it and the games came with printed plastic overlays that clipped into the controller over the keyboard. You might want to consider including some sort of keypad overlay feature into your enclosure - you've gone part the way there with your label insert.