2016年5月24日星期二

oximeter - HR monitor concept note - Chinese

光學式心跳量測簡介(PPG, Photoplethysmography)

http://urclazz.blogspot.tw/2015/09/ppg-photoplethysmography.html

基于反射式原理的腕式血氧饱和度采集装置 Wrist Reflection-type Blood Oxygen Detector
http://oaps.lib.sjtu.edu.cn:8000/oaps/bitstream/123456789/334/1/2013-029-071.pdf

2016年5月23日星期一

Install chromium on old PC

Chromium is open-source as like Chrome OS (closed).
We can't install Chrome OS now, could use Chromim to replace it.
1. Find old desktop or laptop and backup the files to avoid install erasing the files on your device.
2. Download ChromeOS build version, you could refer below link I found from Internet.
3. Download Win32diskimage tool, use this tool could select build Chromium image to write to USB disk.
4. Set up boot sequence to let USB disk priority high then plug in USB and reboot system.
5. After boot up, the system will go into Chromium mode. That could let you install Chromium OS on your device.

links:-
ChromeOs daily builds
http://chromium.arnoldthebat.co.uk/

Win32diskimager:
http://sourceforge.net/projects/win32...

Nordic nRF51 development tutorial

Setting up an example project on the nRF51 DK
https://devzone.nordicsemi.com/tutorials/2/
nRFgo Studio --> Program software device / program application

Testing and using a simple BLE application
https://devzone.nordicsemi.com/tutorials/4/

BLE Advertising, a beginner's tutorial
https://devzone.nordicsemi.com/tutorials/5

Debugging with Real Time Terminal
https://devzone.nordicsemi.com/tutorials/6/

Development with GCC and Eclipse
https://devzone.nordicsemi.com/tutorials/7/

BLE Services, a beginner's tutorial
https://devzone.nordicsemi.com/tutorials/8/

Setting up device firmware update(DFU) on the nRF51 DK
https://devzone.nordicsemi.com/tutorials/9/

The below information is from Nordic, good reference.
https://devzone.nordicsemi.com/tutorials/

Tutorials

Here you can find tutorials written by Nordic employees. If you have a question about or feedback on a tutorial, please ask a question in the questions section and link to the relevant tutorial.

We are regularly adding new tutorials and will try to cover as many areas as possible. Please give us feedback on which topics you are missing here.

Also have a look at the videos on our Youtube channel.

Getting Started

Covers topics on how to get started.

Bluetooth Low Energy

Covers different features of BLE, and how to implement these features with the SoftDevice.

Software Development Kit

Covers examples, libraries and hardware drivers in our SDK.

Hardware and layout

Covers hardware related topics and guidelines for layout.

Design Examples

Covers how to implement different use cases with the nRF52

Capacitive Touch on the nRF52

IPX - content (Chinese)

http://blog.xuite.net/kiwishih/bloglife/20649195-%E6%88%B6%E5%A4%96%E4%BC%91%E9%96%92%E6%96%B0%E7%9F%A5+-+IPX+%E9%98%B2%E6%B0%B4%E5%AE%9A%E7%BE%A9

2016年5月13日星期五

Google search tips

https://support.google.com/websearch/answer/2466433?hl=en
Every day I use Google to find information, research and study the new thing. Until now I found the good tips for improve your searching result. If you are like me using Google search every day, recommend you to read about this tip.
For me, I learn about $, -, * symbols, :site.

Symbol	How to use it
`+`	Search for Google+ pages or blood types Examples: `+Chrome` or `AB+`
`@`	Find social tags Example: `@agoogler`
`$`	Find prices Example: `nikon $400`
`#`	Find popular hashtags for trending topics Example: `#throwbackthursday`
`-`	When you use a dash before a word or site, it excludes sites with that info from your results. This is useful for words with multiple meanings, like Jaguar the car brand and jaguar the animal. Examples: `jaguar speed -car` or `pandas -site:wikipedia.org`
`"`	When you put a word or phrase in quotes, the results will only include pages with the same words in the same order as the ones inside the quotes. Only use this if you're looking for an exact word or phrase, otherwise you'll exclude many helpful results by mistake. Example: `"imagine all the people"`
`*`	Add an asterisk as a placeholder for any unknown or wildcard terms. . Example: `"a * saved is a * earned"`
`..`	Separate numbers by two periods without spaces to see results that contain numbers in a range. Example: camera `$50..$100`

Operator	How to use it
`site:`	Get results from certain sites or domains. Examples: `olympics site:nbc.com` and `olympics site:.gov`
`related:`	Find sites that are similar to a web address you already know. Example: `related:time.com`
`OR`	Find pages that might use one of several words. Example: `marathon OR race`
`info:`	Get information about a web address, including the cached version of the page, similar pages, and pages that link to the site. Example: `info:google.com`
`cache:`	See what a page looks like the last time Google visited the site. Example: `cache:washington.edu`

2016年5月11日星期三

CC2640 VS CC2540 VS CC2650

from https://e2e.ti.com/support/wireless_connectivity/bluetooth_low_energy/f/538/p/417820/1486886#1486886

cc2640 vs cc2541 differences

13885

kazola

Good afternoon!

I want to decide between the CC2640 and the cc2541. Because of this, I would like your opinion on several subjects :)

Where do the power savings in RF come from? In other words, why does cc2541 require so much power compared to cc2640?
How is it possible having 2 ARM in cc2640 consumes a similar value than 8051-based cc2541? I'm not an architecture guy so be kind here ;)
I guess the change to simpleLink came from the need for more memory to fulfill v4.1 and v4.2 features and requirements. I heard cc2640 handles most of v4.1 and it will be able to manage v4.2. What about cc2541 for these two versions?
How many BLE devices may handle the cc2640? There was a limit of.... 3 (AFAIR) in cc2541?
Does the RTOS in cc2640 provide a huge difference in application performance? :) I'm more interested in your subjective opinion here, the "feeling" you have when debugging and running your applications.
Which is the future of cc2541 at TI? In other words, should we discard this chip for new designs? I guess I will be able to extract this information from your previous answers but let me know them explicitly ;)
I'm also interested in any additional thought and/or opinion and/or interesting issue I have not asked about and you may tell me! :)

Well, have the nicest day! :)

1) Basically because the radio is totally redesigned.
2) This is just because the modern ARM processors are more efficient than the old 8051. Additionally we are using new production process, new technology, etc. Adding a built-in DCDC regulator also increases efficiency. Keep in mind though, that none of the numbers in the datasheet are for running both cores simultaneously.
3) You are correct on CC2640. CC2541 will not be able to fulfill all of 4.1 due to RAM limitations.
4) Our current number is 8
5) Everything is faster in the CC2640 compared to the CC2541. Really.
6) The CC2541 will still be supported by us. We also plan to update the BLE stack for CC254x to 1.4.1 this year. It you prefer a device that have been in the market for several years and is mature, and you can live with the current consumption and the 8051 core, the CC2541 is still a good part to use.
7) You can get the CC26xx SensorTag for $29 with a low cost debugger for just additional $15. Get a kit and check it out!

Cheers,
Fredrik

http://processors.wiki.ti.com/index.php/CC26xx_FAQ

The multi-standard CC2650 wireless MCU supports BLE as well as other wireless protocols, such as 802.15.4. The CC2640 supports Bluetooth Low Energy only.
The CC2640 & BLE-Stack v2.0.0 supports BT4.1. At this time, TI has not made any announcements regarding CC2640 support or capability of BT specifications beyond BT4.1.

2016年5月24日 星期二

2016年5月23日 星期一