How to Measure ROOM CO2 concentration with 20$ sensor "MH-Z19" and Raspberry Pi, 2nd edition.

MH-Z19 CO2 concentration SensorMH-Z19 is small, low-cost, weigh 15g CO2 sensor module product by 郑州炜盛电子科技.
You can buy it at online shop like eBay or aliexpress about 20$.

The electrical interface of this sensor is compatible with Raspberry Pi. So you can make your D.I.Y. CO2 Monitor with MH-Z19, Raspberry Pi .

Normal CO2 concentration is about 400ppm. On a global scale, this value is sensitive to the effect of the activities of the plants, seasonally it get lower in summer due to vigorous plants photosynthesis and getting higher in winter, and the long range trend is continue to rise linearly. The Japanese Meteorological Agency report CO2 concentration chart continuously as hire. It indicate clear trend of rising.

On your room scale, in a closed room with 2 person, CO2 concentration rise up to 1,200ppm soon, and keep falling slowly after 1 person go out.

In high CO2 concentration room as 1200ppm, somebody can get a headache or sleepiness.

But no need to concern about it. It fall dow…

Monitoring all over the world with 3G Network for not more than 10$ monthly payment

The MONITOR™ is a free web service which shows the latest posted picture and sensor data. With 2$ USB Camera and Raspberry Pi, you can get your D.I.Y. Monitoring for inexpensive cost.

You can get started MONITOR™ for Free at here!

Even at the place where no available network access all over the world, your Monitoring system still work well with 3G dongle & International Data SIM card.

I write from now how to setup inexpensive 3G network environment on your RaspberryPi easily. USB 3G dongle and Data SIM card utilities "gc_modem" In General, setting of USB 3G dongle and SIM Card is troublesome works with bizarre technical terms, like udev rule, apn, and so on.
The "gc_modem" is usefull utilities to change there troublesome works mentioned above to just select the name of dongle and SIM card which you'll use. 
gc_modem is consist of following parts: udev_rules : Definitions of each USB 3G dongles which will be mentioned.wvdial : Definitions of each DATA SIM ca…

How to send the data of room Temperature, Relative Humidity and Humidity Deficit which get by 3$ sensor "DHT22" and Raspberry Pi to AT&T M2X service, without any electronic works nor any programming.

If you would like to send DHT22 data to AT&T M2X, the UedaTakeyuki/dht22 mentioned before is also support to send data to M2X with following steps.

GOAL  Get DHT22 data and send it to M2X at 5 minits interval.

Create your DEVICE, API-KEY and STREAMs Create DEVICE, API-KEY and STREAMs on your M2X account. For API-KEY, necessary ACCESS for this purpose are only "GET" and "PUT".

Cabling and Mounting DHT22 sensor module on the Raspberry Pi. Please refer my previous post of blog. Install UedaTakeyuki/dht22 Install UedaTakeyuki/dht22  according to this step.  Then also install UedaTakeyuki/handler4m2x according to this step.
That it!

How to get Time Series Chart of the room Temperature, Relative Humidity and Humidity Deficit with 3$ sensor "DHT22" and Raspberry Pi without any electronic works nor any programming.

DHT22 (AM2302) CO2 Sensor Though DHT22 (another name AM2302) sensor is small and low-cost, but have decent quality of precision of measuring temp/humidity.
You can buy the ready to use breakout of DHT22 for 3 - 4$ from eBay.

Why measure the room humidity as well as temperature Not only to get comfortable air, to measure and control humidity has a lot of purpose, for example:
- In hight humidity room like summer or monsoon season on Japan, where I live in, It often grows the mold everywhere on the wall, clothes, food and so on. The mod can't be active under low relative humidity. I'm controlling my room to keep relative humidity under 60% to block to grows the mold. The filamentous fungi, which is many of the causes of plant disease, is in the same family of mold, so a lot of plant disease also can avoid by humidity control. 
- Some plant is known that they close there pore under hight Humidity Deficit (I'll explain this later) to block loosing there moist and dying. With c…

How to make shareable SD card by Raspberry Pi & PC.

Goal Make a Raspberry Pi OS SD card which can be used by both Raspberry Pi & PC (Windows & Mac), for using as:
Taking Camera Image or Sensor Data by Raspberry Pi & write on SD CARDPull out the SD CARD, read it by PC.

Problem Raspberry Pi OS SD Card consist of 2 partition, one is small size (about 44 MByte) FAT32 formatted partition for Linux Boot Loader, and the other is the EXT4 formatted partition for Linux OS.
As mentioned here, Raspberry Pi's First Stage BootLoader mount first FAT partition on the SD Card and start Second Stage BootLoader from this partition. Then, mount EXT4 partition for Linux OS.
The first 44 MByte FAT32 partition is too small to store Camera Images or Sensor Data. But, next EXT4 partitioncan't recognized by neither Windows PC nor Mac.
So, first conceived idea is that adding 3rd partition which is formatted as FAT32, and is enough big for storing data.

This idea is work well with Mac. Both Raspberry Pi & Mac can recognize the 3rd Partitio…

How to make Human Detection Security camera with under 1$ Human Detection Senser, 2$ USB Webam & Raspberry Pi

With under 1$ Human Detection Sensor,HC-SR501

With 2$ USB Webcam,

and Raspberry Pi connected to Internet,

You can make Web Base Security Camera System as followsing:

PIR Sensor There are many type of Human Detection Sensor, some of these watching infrared light ray and cache shutting out of this, or some these using Millimeter-wave radar. PIR(Passive Infrared Ray) Sensor is on of these Human Detection Sensor which watch the change of thermal infrared emitted from hot object like Humans, Birds, and Mammals.
The sensor consist of lens for thermal infrared (white plastic tip in the picture below) and detector device.
Both parts are inexpensive parts and detector is low current consumption parts. So, the advantage to use PIR sensor for Human Detection is:
- Inexpensive - Low current consumption How to setup Step 1. Get account of MONITOR™ and your view_id
On your Web browser, Sign up to MONITOR™, then you can seen following display.

Keep the "view_id" shown in the display, you a…