Month: December 2017

Crypto coins for the partner

Crypto coins for the partner

Bitcoins, Ethereum etc

Somehow you became the proud owner of Bitcoins, Litecoins, Ethereum or some other crypto coins or cryptocurrencies and you have no idea what to do with them or how to access them OR you bought some crypto coins and you want to make sure that your partner knows what to do, just in case.

Really, another article on Bitcoin?

Like others before me, I have recently invested in some cryptocurrencies. Nothing major but enough to pause and think about what happens to my crypto coins if for some reason I cannot access them myself and somebody else needs to do that. That is why I’ve decided to write these articles about crypto coins, nothing technical but more a manual on how to have access to them if for some reason somebody leaves you with some words on a piece of paper. I wil try to stay away from techno speak, this is solely written to get access if you don’t know what crypto coins are but for some reason you need to get to them.

The articles

I will write several articles and you will be able to find a list of all of them by clicking here. Each article will cover one aspect and you can read only the ones you want or read them sequentially. I am by no means an expert and I will not provide any advice on buying or selling coins, so don’t ask 🙂 but if you have questions, please do not hesitate to ask them below one of the articles.

If you want to document for your partner, read on. If you are the partner, you can continue to read the next article, crypto coin the basics.

Documenting for your partner

If you are like me and you want to make sure that your investement in cryptocurrencies does not get lost somehow, it is time to document how your partner (or someone else who needs to be able to get to your crypto coins) can get their hands on the crypto coins.

List your wallets and exchanges

Make a list of all your wallets and exchanges where you have cryptocurrency. In this list make sure you are clear on the name of the exchanges and wallets and, if you are creating a document on a computer, you could add download links or websites to the list. This list is not highly confidential, so it’s ok to create and keep this on a computer. It is also important to list which crypto coins you have per exchange and especially per wallet. Sometimes just knowing the credentials or the backup phrase might not be enough to find all coins. For example, your Bitcoin gold might not be directly visible in your main screen but only visible after you click on a tool (like it is on the Ledger Nano S). Having a list per exchange/wallet will ensure that everything can be found.

Access to wallets and exchanges

Next up, document how to get access to every wallet and exchange you have listed. IMPORTANT!!!! The password and the backup phrase you do NOT type on your computer but rather write out in your printed document. Below a (fake obviously) example of such a document:

password1Just to state the obvious, this information will allow the ‘finder’ of this piece of paper to access your exchanges and wallets which means your crypto coins. Remember, there is no such thing as cancelling an order in the land of cryptocurrencies. This piece of paper is worth money (and how much depends on you). On the other hand, if for some reason you lose access to your wallet and you do not have your backup phrase, your money is lost. What I have done is create two copies of this information except that the second copy is split into two; one part (half the password and half the backup phrase) is with trusted person one and the other half with trusted person two, both in a sealed signed envelope so if my house burns down there is another paper backup of my backup phrase. Neither one can access them (even though I trust them) but combined they can access your crypto coins. So you piece of paper might look something like this:



  • Have a list of all your exchanges and wallets which includes which crypto coins are in each
  • Have a list of how to access each exchange and wallet (maybe create 2 versions of this?)
  • Share the url to these articles (if you like them):


Hacking the SONOFF RF

Hacking the SONOFF RF

Some time ago I bought two SONOFF RF’s, the power switch with an ESP8266 inside. I wasn’t planning on using them out of the box, mostly because I don’t want another app on my phone. I have domotica and I want to control all with the same app. My domotica can control devices based on an http call, so this should work.

While digging around on the internet, I found several sites which explain how to hack the normal SONOFF, without the RF. I liked this page but there are many others. Unfortunately, I couldn’t find any page on how to hack the SONOFF RF so I decided to figure it out myself.

I couldn’t get the ESP in flash mode, no matter how hard I tried. When you’re hacking the SONOFF apparently you can use the button which is connected to GPIO0 to put it in flash mode but that did not work on the SONOFF RF. Finally I decided to connect the GPIO0 to ground straight from the chip and see what happens. That worked!

Let’s look at the chip layout:


The LNA (pin 2) should be easy to find since that is the antenna. I looked at the bottom of the print and found it. Forgive the lousy quality but you can see what I found:

antenna and gpio0

You can see C27 connected to the 2nd pin from the top on the left side. That aligns with the schematic above and this means that the 2nd pin from the right on the bottom side should be GPIO0. It runs to a resistor at which point I soldered a wire to it.

The rest of the connections are the same as with the normal SONOFF:


I soldered a strip to the board, from the button to the top the pins are:

  • 3.3V
  • TX
  • RX
  • GND
  • GPIO14

You connect the 3.3V to your FTDI module on the 3.3V, TX on SONOFF RF to RX on FTDI, RX on SONOFF RF to TX on FTDI and GND to GND. What I did is put a break switch on the line to the power because that way I can quickly reboot the SONOFF RF without unplugging the FTDI (reboot to put it in flash or take it out of flash):
(forgive the sloppy soldering 🙂


Almost there… Now I want to be able to put the SONOFF RF into flash mode whenever I want and apparently the button does not work. So I soldered a small push button (break if not pressed) between my wire on the bottom and GND but I made the button at the top so I can access it easily. I passed the wire to the front:


and connected it to the GND of the button of the SONOFF RF (which is the left side in the picture below) via a small push button:


Now if I want to put the ESP in flash mode, I push the button on the power cable (cutting the power to the ESP), push the small button (connecting GPIO0 to GND), release the power button (which boots the ESP) and after a short while release the small button because the ESP will now be in flash mode.

Now that I can program the ESP I can figure out why the regular push button does not work to connect GPIO0 to GND like in the normal SONOFFs.

In short, these are the connections:

  • The relay is connected to GPIO12
  • The led is connected to GPIO13
  • The button is connected to GPIO0

Even though the button is connected to GPIO0, pushing it however only brings GPIO0 to GND for a short while. Even if you keep the button pushed, it only briefly connects GPIO0 to ground which is why you cannot use the button to put the ESP in flash mode. The reason for that is that the RF module also does the same. Pushing the button on the remote actually causes GPIO0 to connect to GND which is probably why they did something different with the button than in the normal SONOFF.

Now that we know that we can build the program. We need to control the relay and the led and we need to watch the button/RF button through GPIO0.

I have created this simple program which should do the trick:

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>

// Replace with your network credentials
const char* ssid = "YourSSID";
const char* password = "YourPassword";

ESP8266WebServer server(80);

String pagePart1, pagePart2;

int sonoffLed = 13;
int sonoffRelay = 12;
int sonoffButton = 0;
bool buttonState = false;
bool powerState = false;

void powerOn (void) {
  powerState = true;

void powerOff (void) {
  powerState = false;

void switchPower (void) {
  if (powerState) {
  } else {

void setup(void){
  pagePart1 = "<h1>SONOFF Switch</h1><br><br>Your switch is ";
  pagePart2 = "</font>.<br><br><a href='on'><button>ON</button></a> ";
  pagePart2 = pagePart2+<a href=\"off\"><button>OFF</button></a></p>";  
  // preparing GPIOs


  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
  Serial.print("Connected to ");
  Serial.print("IP address: ");

    String tmp = pagePart1+"<font color=";
    if (powerState) {
      tmp = tmp+"green>on";
    } else {
      tmp = tmp+"red>off";
    tmp = tmp+pagePart2;
    String tmp = pagePart1+"now switched <font color=green>on"+pagePart2;
    String tmp = pagePart1+"now switched <font color=red>off"+pagePart2;
  Serial.println("HTTP server started");
void loop(void){
  bool currentState = digitalRead(sonoffButton);
  if (currentState!=buttonState) {
    buttonState = currentState;
    if (buttonState==LOW) {

The nice thing about the way the SONOFF RF is designed is that the RF part is completely separate from the ESP part so after reprogramming the ESP, the RF still works as originally designed. This means that you can still program the RF receiver as you would normally:


Press the button on the SONOFF RF twice quickly and than press a button on the remote. This button will than be linked to the RF and can be used, with the above program, to turn the switch on and off.