maemo.org - Talk - Producing Qwerty OtherHalf --order counter: 75/75 --ordering closed

maemo.org - Talk (https://talk.maemo.org/index.php)

- The Other Half (https://talk.maemo.org/forumdisplay.php?f=59)

- - Producing Qwerty OtherHalf --order counter: 75/75 --ordering closed (https://talk.maemo.org/showthread.php?t=91535)

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Nokia is full of patents. Combination of N950 and E90. This is just an idea never seen. Possibility to choose:
- Keyboard out for use, typing position
- At the backside when not needed and the screen is clear.
- covering the screen just like E90, when not using the phone.

I've never seen anything like it. Could it also keep camera clear in any position? Think about it...

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Quote:

Originally Posted by kimmoli (Post 1407256)

Looks nice. Should give a test-print for this..

Two things did came to my mind;

Check center of gravity if it is intended to stand up on a desk, so it won't tip over. All weight is now on the phone side.
In sliding mechanisms, there should be suitable 'ratio' between two lengths (green/blue) to prevent it from getting stuck.

It is stable from 31 degrees and up

The mechanism is from the bluetooth keyboard, so I am sure that will work like a charm :)

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

The PCB in the bottom layer:

(a piece of art if I may say so!)
http://oi44.tinypic.com/2ezqjhj.jpg

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Nice... route e.g. GND between I2C SDA and SCL to minimize crosstalk. (same with INT...)

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Quote:

Originally Posted by kimmoli (Post 1407322)

Nice... route e.g. GND between I2C SDA and SCL to minimize crosstalk. (same with INT...)

Good tip! Had not thought of that!

Changed it to:

SDA - GND - SCL - GND - INT - V3.3

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

also add some bypass capacitors...

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Quote:

Originally Posted by kimmoli (Post 1407331)

also add some bypass capacitors...

Ha! Too late! Chines holiday's starting, so had to order fast! Fedex shipping this time :)

http://oi43.tinypic.com/2r46a6c.jpg
http://oi41.tinypic.com/2iutkis.jpg

-made possible by all the awesome people who donated!-

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Quote:

Originally Posted by Redfizh (Post 1407258)

Feel free to make as sketch to convince me, I am focusing on the current design! :)

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Even though you already ordered the PCBs, I'll give you some comments:

- I2C lines need pull-up resistors. They most likely exist on the Jolla side so it should work without them.

- Ground plane on the bottom layer underneath I2C lines would have been a good idea.

- In general, fill the pcb with ground planes (where there isn't anything else)

- Test pin (pin 37) should be grounded.

- Thermal pad should usually be connected to GND. Datasheet does not mention anything about its electrical connection so most likely it can be left unconnected. That circuit is so low power that heat shouldn't be an issue.

Re: [WIP] Building OtherHalf keyboard prototype --fast times!

Quote:

Originally Posted by TemeV (Post 1407378)

The chip also has internal pull-ups so that should be fine! When/if I order a larger batch (lets say 100), I will post the files first so everyone interested can review them :)

Quote:

Originally Posted by TemeV (Post 1407378)

- Test pin (pin 37) should be grounded.

- Thermal pad should usually be connected to GND. Datasheet does not mention anything about its electrical connection so most likely it can be left unconnected. That circuit is so low power that heat shouldn't be an issue.

Totally missed the test pin :( hope it'll work, will change it for future designs!

No ground plane under thermal pad was on purpose, watched a lot of youtube clips on hand sondering (with solder-iron or heat gun) and all of the said that ground planes under these chip were not easy at all to solder!