As I wrote a sketch for my stepper motor controlled by Blynk, I found the push button caused stepper motor did 2 revolutions for each push.

Using ESP8266-01 module as a shield to Arduino Uno is hard to establish. I took a week to google around to get and fix several issues for this arrangement.

In this article, Arduino Uno will use ESP8266 as a shield and communicate between this devices using SoftwareSerial at uncommon pin D2 and D3. Common serial communication pin D0 and D1 will be left as debugger or for console. I will use Blynk sketch as for the programming.


I subscribed Unifi in April 2018. In my house, it is more than 10 devices connected to my router including IoT devices.

One day, my sister told me that her smart phone and notebook not connected to internet. From her information, we might assume Unifi service is bad. However, HyppTV and other devices has connection to internet via wifi since it located near the router. My sister accessed internet from her room up stair.


I did some troubleshoot. I brought her device and notebook near the router also did not solve the problem. What I found, wifi connection was there but it unable to get IP address from router. It got IP address 169.*.*.*. This is not good.

I restarted all Unifi equipment didn't help either.

I have been wasting 3 week (until today) to figure out what wrong was with my image development. With the same Windows base i used since early this year, I kept updating it until I stuck whenever I launch DELL Image Assist to develop image.

Today, I found that the minimum requirement might not only rely on RAM and storage space. Also, the number of CPU core.