Johan Larsbys guide to China.



So I’ve been to China and it was weird, weird and awesome. There are some things that are totally different in China, and some I knew about, and some I had no idea about and had to learn the cumbersome way. I’m collecting these wisdoms here for you dear reader to benefit from.

* Chinese language and english: Chinese is built in a way that is very different from English. No bending of words, so nothing like greener or bigger. In Chinese it would be more green or more big. When I understood this it was easier to understand stuff. “I know” does not mean the same thing in Chinese, it means “Thank you for explaining, I understand now.” Not what we might think as “Shut up, I know all this already.”

* Food. All I met wanted me to know a lot about China and Chinese foods. Sometimes though, they order “local delicacies” that they wont eat themselves. While this might make a fun story back home I’m not ashamed for skipping a few delicacies that no-one else ate. Always drink water from bottles. Bīng means cold, learn this word. Exercise in front of the mirror your best impression of being cold. Otherwise you will have to drink everything lukewarm.

* Medicin: I had packed several packs of Dimor, a Loperamide that stops with diarrhea. I always had one on my person. One in my backpack. One in my suitcase and one in my toiletry case. Yes I needed to use it. I also packed all other medication I thought I would ever need.

* Internet. Internet in China sucked where I was. Everything is blocked in all of China. Get a VPN service before (if you have gmail or files in dropbox). Then get a backup VPN Service as well, maybe on one of your home computers. And then get a web surfing proxy installed on a web server somewhere

* Taxi. Taxis are scary, get a Uber app (there are several) and get those cabs instead. Much safer. Also, apparently there is no law that requires seatbelt in the backseats of cars. And you get looked at funny if you ask for it in a regular cab.

* Electric outlets. You don’t need to worry about it. In the places I’ve been they have _all_ the standards. Worst case buy a power strip that extends to a lot of different devices. Everything I found was at around 220-230v.

* Toilets, you really need to know (at least in theory) how to use a squat toilet. I did not and apparently (after reading up on the internet) I now know that I used a very hilarious solution. HowTo Link


P.S. These advice are not everything you need. Normal stuff, like what is the difference in weather from where you are currently at and all that other stuff still applies.

Wifi enabled mailbox.

Yeah, I built one!


So I’ve been toying around with the ESP8266 wifi chip, and I also hate walking outside to check if the mail has arrived in my mailbox, also this one is old and does not look very nice.

Solution to this partly artificial problem?
Use a ESP8266 to connect to my wifi every time the mailbox is opened, get a php page that downloads sends an email to me with the exact time the mailbox was opened.




I ran into a few snags, battery wise I want it to last forever, and ever. So decided to make the ESP turn itself off, that turned out harder then I thought and I had to get both additional hardware and also help.

First things first though, the ESP8266 is running Arduino, so I thought that buying a I could get the esp to tell the pushbutton power switch to turn itself off.  And that worked to a degree. The boot time of EPS was to long and the pin had to be did not have time to change to a correct value so it immediately shut down. It’s a latching thing. That is when I got help, Jesper told me that I could make a ramp with a resistor and a capacitor and then he helped me calculate the values.
Long story short, I thought it would work, it didn’t, then I got help, and then it worked again.


Was the way to my “no dry run utopia” without fail? No. It was actually full of fail. First I made a new mailbox with the kids, in wood. And I used BTLE to communicate from the mailbox. The wooden mailbox did not turn out as stylish as I hoped it would, so I bought the red metal one. BTLE did not reach the house, so that was also useless. Anyways onwards to the pretty pictures and actual code.




And then transferred to vero board and inside the new mailbox




Arduino code:

#include <ESP8266WiFi.h> 
 const char* ssid = "LarsbyFiber";
 const char* password = "***********"; 
 const char* host = ""; 
 int outpin = 0; 
 void setup() {
 pinMode(outpin, OUTPUT);
 //Set digital pin 7 LOW. HIGH turns off the Pololu Pushbutton Power Switch
 // We start by connecting to a WiFi network 
 Serial.print("Connecting to ");
 WiFi.begin(ssid, password); 
 while (WiFi.status() != WL_CONNECTED) {
 Serial.println("WiFi connected");
 Serial.println("IP address: ");
 Serial.print("connecting to ");
 // Use WiFiClient class to create TCP connections
 WiFiClient client;
 const int httpPort = 80;
 if (!client.connect(host, httpPort)) {
  Serial.println("connection failed");
 // We now create a URI for the request
 String url = "/****.php";
 Serial.print("Requesting URL: ");
 // This will send the request to the server
 client.print(String("GET ") + url + " HTTP/1.1\r\n" +
 "Host: " + host + "\r\n" +
 "Connection: close\r\n\r\n");
 // Read all the lines of the reply from server and print them to Serial
 while (client.available()) {
 String line = client.readStringUntil('\r');

 Serial.println("closing connection");
 //Turning off
 Serial.println("Turning off.");
void loop() {
 //lol no!

PHP Code:


 $tz = 'Europe/Stockholm';
 $timestamp = time();
 $dt = new DateTime("now", new DateTimeZone($tz)); //first argument "must" be a string
 $dt->setTimestamp($timestamp); //adjust the object to correct timestamp

 $admin_email = "";
 $email = "";
 $subject = "redbox opened at: " . $dt->format('d.m.Y, H:i:s');
 $comment = "";

 echo $admin_email;
 echo "<br>";
 echo $subject;
 echo "<br>";
 echo $email;
 echo "<br>";

 mail($admin_email, $subject, $comment, "From:" . $email);

 echo print_r(error_get_last());


As an end I want to show you the wooden mailbox that we ended up converting to a very hipsterish backpack rather then using as a new mailbox. it’s available since I have all the backpacks I can use (holds a macbook pro 15″)