Added sonar example, fixed URL-s

Makefile

@@ -13,7 +13,3 @@ flash:
 console:
 	echo "Ctrl-A + Ctrl-Q to close Picocom"
 	picocom -b115200 /dev/ttyUSB0
-	
-dep:
-	sudo apt install python3-pip
-	sudo pip3 install adafruit-ampy

README.md

@@ -2,14 +2,23 @@
 
 ## Getting started
 
-MicroPython project skeleton
+This howto assumes Ubuntu 16.04 is used on the computer and several tools have been installed:
 
 ```
-git clone http://git.k-space.ee/lauri/micropython-skeleton
+sudo apt install picocom make python3-pip
+sudo pip3 install esptool.py adafruit-ampy
+```
+
+Clone the Git repository and run makefiles:
+
+```
+git clone https://github.com/k-space-ee/micropython-skeleton
 cd micropython-skeleton
 make
 ```
 
+## Blinking LED-s
+
 First let's some LED-s blinking.
 Press Ctrl-E for paste mode, otherwise spaces get mangled.
 Press Ctrl-Shift-V for pasting.
@@ -47,7 +56,7 @@ Tasks:
 
 
 
-# Button presses
+## Button presses
 
 On the board there is button labelled "Boot", this is hooked up to pin 2.
 By default there is a resistor which pulls the voltage on the pin to 3.3v, but when button is pressed the pin is shorted to ground so the voltage goes to 0v.
@@ -79,7 +88,7 @@ Tasks:
 
 
 
-# Driving OLED screens
+## Driving OLED screens
 
 Let's get some pixels on the screen.
 There's 128x64 pixels monochrome OLED screen connected via I2C bus on the pins 4 and 5.
@@ -107,6 +116,13 @@ Tasks:
 
 Next let's hook up DHT11 sensor to the board and measure the temperature.
 
+* Sensor's Vcc is connected to 3.3v on the board
+* Ground pins (GND) are connected
+* Sensor's data pin is connected to board pin 4
+
+Some code to get you going:
+
+
 ```
 from time import sleep
 from machine import Pin
@@ -129,6 +145,46 @@ Tasks:
 
 1. Get temperature and humidity displayed on the screen
 
+
+## Distance with sonar
+
+In this case HC-SR04 is hooked up:
+
+* Trigger is connected to pin 25
+* Echo is connected to pin 26
+* GND pins are connected
+* Sonar's Vcc is connected to 3.3V on the board
+
+Code to measure distance:
+
+```
+from time import sleep_us, sleep_ms
+from machine import Pin, time_pulse_us
+
+trigger = Pin(25, Pin.OUT)
+echo = Pin(26, Pin.IN)
+
+def measure():
+    trigger.value(0)
+    sleep_us(5)
+    trigger.value(1)
+    sleep_us(10)
+    trigger.value(0)
+
+    duration = time_pulse_us(echo, 1, 29000)
+    distance = (duration / 2.0) / 29
+    return distance
+
+while True:
+    print("Distance is: %s cm" % measure())
+    sleep_ms(200)
+```
+
+Tasks:
+
+1. Get distance shown on OLED display
+
+
 ## Connecting to internet
 
 Exit the serial console by pressing Ctrl-A and then Ctrl-Q.
@@ -176,9 +232,10 @@ Using web browser navigate [here](http://iot.koodur.com/demo2.html#living-room-o
 1. Move to another channel to prevent flipping lights in my living room
 2. Improve the code so the "Boot" button and button in the web interface both work simultaneously
 3. Download the HTML file and add buttons to select different colors, adjust Python code to handle new commands
+4. Add code to send sensor readings to the webserver
 
 
-# Summary
+## Summary
 
 ESP32 microcontroller with MicroPython is a really cheap way to get started with the IoT stuff. See more detailed information [here](https://lauri.xn--vsandi-pxa.com/2017/06/espressif.html).
 
@@ -191,3 +248,5 @@ Other interesting projects with ESP8266 and ESP32 microcontrollers:
 
 * [Nixie clock](https://github.com/k-space-ee/nixiesp12) with ESP8266
 * [Sumorobot](http://robot.itcollege.ee/sumorobot/2017/08/25/sumesp-prototype/) with ESP32
+
+Come and visit [k-space.ee](https://k-space.ee) on Wednesdays 18:00 for more of MicroPython