Raspberry Pi - fully working computer at the cost of RM300++ (best for home use during and beyond MCO period)

During current Movement Control Order (MCO) period, there are quite a lot of schools have resorted into online teaching and learning mechanism. There are also quite a lot of companies practicing work-from-home (WFH) concept.

However, this raised a question: what if the family does not have a computer at home? And, what if the family only has one computer at home, but needs to be shared by parents who need to WFH and also multiple children who need to learn from home?

Well, you can buy a fully working computer online, including additional computers needed for all your family members, at the cost of RM300++ each, in the condition that you have a screen (either computer monitor or TV) at home, and Internet access (either phone's hotspot sharing or broadband Internet).

The full set Raspberry Pi (recommended for Version 4 model B with 2GB RAM) with all its required accessories, is a fully working computer at the cost of about RM300-RM360 only. Beside its low cost, it also consumes minimal amount of electricity and requires minimal storage space due to its small size.

It is good enough for normal online learning, doing assignments with office suite (word processor, spreadsheet, presentation slides, database, etc.), and some entertainment including games.

With about RM360, you can buy the following full set of computer:

• Raspberry Pi 4 Model B with Quad core CPU and 2GB RAM - RM174
• Casing for the Raspberry Pi 4 Model B - RM25  (*1)
• Official Raspberry 15W power adapter - RM35
• Micro-HDMI to HDMI cable - RM10
• Wired earphone - RM15 (*2)
• 16GB micro SD card preinstalled with NOOBS - RM36 (*3)
• Logitech MK220 wireless keyboard & mouse - RM65 (*4)

*1: The casing is an optional item. Without the casing, the Raspberry Pi will be a naked computer board as shown in the image above. With the casing, it will look like below:

*2: If you connect the Raspberry Pi to your TV using HDMI cable, you can make use of the audio output from your TV. You need an earphone or speaker, either wired or Bluetooth, to listen to the audio from Raspberry Pi if you are using a monitor without audio output.

*3: Raspberry Pi makes use of micro SD card as its "harddisk". You can also buy a blank micro SD card, which is much cheaper, and download NOOBS for free from Raspberry's website. That will require some basic computer knowledge to download and install NOOBS into the micro SD card. NOOBS is an installer that will prepare the SD card for Raspbian (including partitioning, etc.), and automatically download and install the operating system into it.

*4: Alternatively, you can also use cheaper USB wired keyboard & mouse to further reduce the cost.

The recommended operating system will be Raspbian, a scaled down version of Debian Linux. It has fully functioning Chromium or Vivaldi web browser, LibreOffice resembling the Microsoft Office, and tonnes of installable free softwares in Raspbian repository. This is good enough to access to Google suite of applications (Gmail, Google Drive, Google Docs, Hangout, ...), watch online & offline video, listen to online & offline music, access to learning portal and other websites, attending audio/video conferencing, etc.

There are also programming tools and graphic design software available in Raspbian for learning purpose.

In fact, you can install a full LAMP stack in Raspbian and turn your Raspberry Pi into a web application server as well.

The Raspberry Pi 4 Model B also supports webcam and voice input with additional module, which will need additional cost to buy and some technical skill to assemble.

Beside Raspbian, there are other choices of operating system that works with Raspberry Pi too, including Microsoft Windows 10 IoT Edition, which you can explore if you are enthusiastic with them.

Huawei Watch blood oxygen saturation (SpO2) measuring feature

Blood oxygen saturation (SpO2) is a feature in the latest Huawei and Honor smart watches.

Image from Huawei's website

This feature is available in the Huawei Watch GT2 sold in China, but had somehow been disabled in that model sold in the international market. Anyhow, this feature has now been enabled to Huawei Watch GT2 sold outside China as well, following its firmware update version 1.0.6.26 and above (latest firmware version as of now should be 1.0.6.32).

SpO2 represents an estimation of oxygen levels in a person’s bloodstream. According to description in Huawei's website, "blood oxygen saturation (SpO2) is one of the important vital signs that can reflect the oxygen supply of the body. Very low levels of SpO2 can result in serious symptoms such as lack of energy, fatigue and light-headedness."

Under normal conditions, a healthy person should have an SpO2 level between 90 and 100.

The heart of an average adult normally pumps about 5,000 ml of blood per minute to the tissues and organs of the body, delivering about 1,000 ml of oxygen per minute to the body. Body function will be affected if the oxygen is at low level, causing hypoxemia and even hypoxia problem.

There are 2 types of hypoxemia. Acute hypoxemia occurs over a relatively short period of time, while chronic hypoxemia is ongoing over a longer period.

Common symptoms of acute hypoxemia include: shortness of breath, rapid breathing, wheezing, cough, confusion, headache, fast heart rate, and bluish colour in skin, fingernails and/or lips.

Common symptoms of chronic hypoxemia include: pulmonary hypertension, cor pulmonale (enlargement of right-side of the heart), heart failure, and polycythemia.

People who are having a higher risk of hypoxemia should regularly check their SpO2 level. You are one of them if you are:

• always on a busy work schedule
• working or living in a stressful environment
• working in a situation that needs to use a lot of brain everyday
• located in a place of high-altitude (with low atmospheric pressure)
• elderly people (with decreased body function)
• snoring a lot or having sleep apnea problem (might cause respiratory obstruction)
• having heart defects
• having lung conditions, including asthma, emphysema, bronchitis, corona virus infection, etc.

Huawei SpO2 sensor technology makes it easy to measure SpO2 level, anytime, at any place. Clinically, SpO2 level is measured using arterial blood gas (ABG) test, pulse oximeter, etc.

To measure SpO2 with a Huawei / Honor watch or band that supports the feature, just keep your arm still, fasten the strap tightly, and make sure the screen is facing up. Then, swipe on the screen for the SpO2 function, and start your measurement. It will take about 1 minute to complete.

Using Android phone's camera as webcam for computer with DroidCam

You need a webcam in order to do video conferencing, or to do vlogging, or to perform online talks, ...

You might have a desktop computer with a monitor that without a camera (which is usually the case), or you need a better camera than the one on your laptop (which usually has a low resolution), or you need a replacement for your malfunctioned laptop camera, or for whatever reason that you need a webcam for your computer, wait a minute and read this before you go and purchase a physical webcam, because you can turn your Android phone into one.

DroidCam is a solution to let you make use of the camera on your Android phone to become the webcam of your computer running on either Windows or Linux operating system.

It has a pretty low hardware requirement, so you can easily turn your old Android phone with a functioning camera into your webcam. Of course, it is even better when you run it on Android phone with better specs.

All you need to do is download and install DroidCam Wireless Webcam by Dev47Apps from Google Play Store, and then download and install DroidCam client into your computer.

• Download webpage of DroidCam for Windows
• Download webpage of DroidCam for Linux

Beside video, DroidCam is also able to optionally stream audio from the microphone of your phone to your computer.

DroidCam can connect and stream to your computer either through WiFi, USB or HTTPS connection. WiFi is the preferred one, as it is the easiest to setup and use.

When you run the DroidCam app in your phone, you should be able to see its connection information, including the internal IP address of your handphone, and the DroidCam server port.

By default, DroidCam is using the back camera of your phone (which usually has a better spec than the front camera). You can switch it to the front camera in DroidCam setting.

If you run the DroidCam Client in your computer with the IP address and port number as shown on the DroidCam app in your phone, and click the Start button, you should be able to see the video captured by your phone's camera in DroidCam Client.

For example, before clicking the Start button in DroidCam Client, there is no webcam video shown in Skype. It will show a blue or green background.

After clicking the Start button, Skype will immediately captures the webcam video.

Note that Skype install through Microsoft Store is not working with DroidCam. If you encounter this problem, just uninstall Skype and install the Skype desktop version from the URL given below. It should work then:

• https://www.skype.com/en/get-skype/

On your DroidCam screen in your phone, you can also find 2 HTTPS links.

The first link is accessible from your web browser such as Google Chrome, and it will open up the DroidCam web client.

The second link is accessible with video streaming client, such as VLC Media Player. The setting for VLC Media Player is as below:

DroidCam has a feature to allow you to protect your HTTPS access with username and/or password.

DroidCam is free for use, with in-app ads support. You can also buy DroidCamX Wireless Webcam Pro in Google Play Store to remove the ads and to get more features.

You might probably also be interested to read about:

• Using Android phone's camera as webcam for PC and Mac with Iruin