liutyi.info – Page 2

D9 Air Quality Detector

This time OCRKJ D9-H. Which also can be found in some shops as unbranded LCD Digital Air Quality Monitor (AKA monllac, AgoHike, Robincure). Similar to OCRKJ K6-D from the previous review. It was bought for about 100$. Yet another portable device with 10 hours battery life and correct CO2 measurements.

Pros

3000 mAh battery ( 10 hours of battery life)
additional sensors (HCHO, VOC and PM2.5)
16 different screens including trends
Active airflow with the relatively quiet fan
quality design and schematic inside (no glues, connectors, replaceable sensors)
good CO2 sensor inside – SenseAir S8 LP

Cons

slow charging – 8 hours (in operation mode)
no connectivity (Bluetooth, wi-fi, USB mass storage)
no ambient light sensor
unconfigurable high CO2 limits (GOOD is up to 1000 ppm)
wrong temperature and RH measurements (+3C, -10%RH)

It looks like relatively cheap SHT20 temperature and humidity sensor inside make it sort of a lottery if you will get correct measurements or not.

See device insides: https://wiki.liutyi.info/display/CO2/D9+Inside

SALE Price was: 102$

Tags CO2, HCHO, PM2.5, VOC

air quality

K6 Air Quality Detector

I was not expecting much ordering KKMOON K6 (and receiving actually OCRKJ K6). Which also known as CAFU K6. Because most of the portable air quality monitors I got before have at least one major issue with measurements (AiRead M3 – all measurements wrong, HT-501 – wrong temperature, AirRadio A6 – issues with CO2 measurement after outdoor use and wrong humidity measurements). AirVisual Node was the only exception that both portable and show correct numbers. But it just too big to put it in your pocket. So there was a long history of portable CO2 monitors with issues. And it was kind of a surprise that the device I bought for 83$ is both portable and displays more or less correct numbers.

Pros

3000 mAh battery ( 10 hours of battery life)
additional sensors (VOC, PM2.5)
correct t, RH and CO2 measurements (not sure about other)
16 different screens including trends
Active airflow with the relatively quiet fan
quality design and schematic inside (no glues, connectors, replaceable sensors)
good CO2 sensor inside – SenseAir S8 LP

Cons

slow charging – 8 hours (in operation mode)
no connectivity (Bluetooth, wi-fi, USB mass storage) – nothing
no ambient light sensor
unconfigurable high CO2 limits (GOOD is up to 1000 ppm)

See device insides: https://wiki.liutyi.info/display/CO2/K6+Inside

Price: ~100$ (sale price was 83$)

Tags CO2, PM2.5, VOC

power bank

Tqka Power Bank 10000 mAh

Post author By liutyi
Post date 2019-01-10
No Comments on Tqka Power Bank 10000 mAh

In the future fast charging might get some common ports and protocols. And it seems it will be type-c with USB Power Delivery in use in most cases. But for the moment it is several standards that provide more power than a standard USB port. Those standards are mostly not part of USB specification. And it is kind of unusual to have charger or power bank that support multiple fast charge protocols for different devices. That cause slower charging of some phones using charger or power bank designed for another. For example, at the moment most Qualcomm and Mediatek based Android smartphones have different fast charging standards. It took some time for me to find MTK-PE+QC3.0+Apple2.4 charger and power bank.

So the power bank is Tqka BA058

List of supported protocols

Qualcomm Quick Charge 2.0 (QC2.0)
Qualcomm Quick Charge 3.0 (QC3.0)
Mediatek Pump Express 1.0 (MTK-PE)
Mediatek Pump Express 2.0 (MTK-PE2.0)
Huawei Fast Charge Protocol (FCP)
Samsung Adaptive Fast Charging (AFC)
USB Battery Charging 1.2 (BC2.1)
Apple 2.4A

air quality

Awair 2

Post author By liutyi
Post date 2018-12-13
No Comments on Awair 2

Awair 2-nd edition is a better version of Awair, that fix some known issues of first edition

Awair 2-nd edition

What was fixed and added

24h time format
USB Type-C standard 5v power connector
USB 5v 2A standard power supply
Better display (resolution, no backlight)
Ambient light sensor (display auto brightness)
Microphone (not sure if it is good to have it on IoT device)
Better PM2.5 sensor
New buttons to switch the display mode
Better wireless connectivity (new antennas)
Better (active) airflow

Tags CO2, PM2.5, VOC

apple Devices

SeekThermal CompactPro

SeekThermal CompactPro (300~500$ on Amazon) is an accessory that allows you to shot thermal photos or videos. Available for Android and iOS devices

Example video (time lapse done in an external application)

apple iphone

Umidigi Q1: iPhone X charging

Post author By liutyi
Post date 2018-07-06
No Comments on Umidigi Q1: iPhone X charging

Umidigi Q1. 15 Watt Qi charger for Umidigi Z2 Pro (that is not yet released). It should also charge iPhones with 7.5W max.

Apple iPhone X charging time:

	50%	80%	100%
PC Port USB 2.0	03:00:00	04:40:00	06:10:00
Umidigi Q1	01:28:00	02:28:00	03:34:00
Apple 5W charger	01:25:00	02:05:00	03:25:00
Umidigi Q1 + extra fan	00:55:00	01:48:00	02:40:00
Apple 12W charger	00:35:00	01:05:00	02:10:00
Apple 29W charger	00:30:00	00:55:00	01:55:00

Charge in case without extra cooling

Charge with no case and with additional external cooling

Tags Qi

air quality

XINTEST HT-501 CO2 Meter

Portable CO2 meter and data logger with battery and good CO2 sensor inside.

The only really wrong thing about this device is it always show temperature higher than it is for about 2°C (for example 28.0°C instead of 26.0°C) and it is not something related to wrong sensor placement.

Pros

Portable
20h work from a battery
LCD Color zoning
Datalogger
Setup time and alarms from PC
Sensair S8 CO2 sensor

Cons

Incorrect temperature measurements
No time and date on the screen
30 sec warmup time

Tags CO2

air quality

uHoo

Post author By liutyi
Post date 2018-03-28
No Comments on uHoo

uHoo – most advanced air quality monitor, at least if consider a number of sensors. Including advanced sensor like CO, CO2, PM2.5, VOC, O3, NO2. And also traditional like temperature, humidity, and air pressure. Measurements look accurate enough.

The device does not have any local indicators. Not a single color LED to show air quality status. The only way it communicates with the world is Wi-Fi and mobile application. The application (v 3.8) or backend infrastructure that makes it work is unfortunately unstable. Also, an interface is poorly adapted to iPhone X.

uHoo is not portable due to many reasons like no local indication, no battery, need Wi-Fi (and new connection setup will take time).

Tags CO, CO2, PM2.5, VOC

Android Devices

Samsung S8 AFC charging time

Post author By liutyi
Post date 2018-03-12
No Comments on Samsung S8 AFC charging time

Long time no Samsung. 🙂 Mostly because of the previous experience (read in Russian). But anyway did a test of Adaptive Fast Charging (AFC) from Samsung. Using Samsung S8 with AFC charger from the box.

What can I say?
I see some cheating with charging percentage displayed by the phone to get “Full Charge in 90 minutes” in reviews.

But the real numbers are more like 120 minutes.

Just to compare with a device that shows true percentage see image below

	50%	80%	Show 100%	Real 100%
Apple iPhone 8 5v 12W charger	00:28:00	00:51:00	01:41:00	01:41:00
Samsung Galaxy S8 AFC	00:44:00	01:08:00	01:28:00	01:56:00

air quality

Green Day CO2 Monitor

One of the oldest devices I got for CO2 monitoring is AZ-7788 GreenDay. It is 4 years old now. The device is still good and accurate.

Used as portable mostly because it has an LCD and not require setup.

Tags CO2