digital-adjustable portable PowersupplyUnit with Arduino-Heart

digital-adjustable portable PowersupplyUnit 

with Arduino-Heart

This is a project i´m thinking about for a couple of month now. There was a lot of reading work todo to get a breadboard prototype up and running. I wanted to keep everything as small as possible without loosing some of the planned features.

The main specifications are:

- fixed powersupply with 5V and 3.3V for most MCUs

- an adjustable Powersupply with min. 1A + adujstable current limiting

- an OLED Display (0.96")

- 3 Buttons for navigation & setting including voltage and current adjustment

- small enough to put in a notebook-bag

- log data via Serial (maybe also adjust some settings)

- Power via notebook PS

- build everything around an Atmega328P-PU with 8Mhz internal clock (Breadboard-Arduino)

At the moment i am able to provide the latest schematics of the electronics-setup.

Refereing to the schematic you will notice that i used linear voltage regulators (7805 for 5V, 78M33 for 3.3V and an LM317 for the adustable part). The second 7805 is used to provide power to the MCU (shortcircuiting the other 5V will not lead to a reset of the MCU). 

The voltage adjustment of the LM317 is done by PWM. The PWM signal runs over th R-C Filter (R3 and C9) which will make a nice analog Voltage out of it (if you encounter problems here, try a 1µF C). The Analog Voltage is than amplified by an OP-Amp and feeds the ADJ PIN of the LM317. 

The measurement of the Vout is done with one of the ADC-Pins via the voltagedivider R9 and R8. The Current measuring works nearly the same way this is done via R2 which will be in series to the load on the output. So the load an R2 will form a V-divider and the voltagedrop on R2 will refer to the currentflow (Ohms-LAW). The measured voltage (the v-drop is pretty small) is amplified by an OP-AMP and fed into on of the ADC-Pins. The current limiting itself will be done via software (not as fast as a hardware solution, but enough that you won´t fry evry LED). So If the measured current is higher than the Imax setting the voltage will be decreased by the software till I is in the Limits of Imax. Sounds easy? Well that was a hard nut to crack :-).

So if you are interested, stay tuned! I will provide the Arduino-sketch + some pictures & maybe a Video of the working PSU soon.

ATTINY-RAT, ATTINY85 powered mini lightfollower

ATTINY-RAT, ATTINY85 powered mini lightfollower

The last couple of weeks i´ve done some testing with the ATTINY85 chip. It was really fun to experiment with this little MCUs. Compared to their size they are pretty powerful and a cheap solution for smaller projects.

If you plan to tinker with those chips i can highly recommend to build a programmer-shield for Arduino. There are tons of articles in the Internet so just ask google. I build mine according to the schematics of avdweb.nl. (see picture). I also included pinout diagrams of the ATTINYx5 and x4 chips.

To get you started with ATTINY and Arduino i recommed to follow this Instructions.

The project itself was documented by me on Instructables. Just follow this LINK.
If you are not sure just check the pictures + schematics below.

ArduinoHomeAutomationProject: The Bridge-Processing-Software

The BridgeProcessing-Software

Overview in Processing

THE CODE

This is my approach to store serial-data into a SQL Database. I will describe the RPI Setup later.

import processing.serial.*;
import de.bezier.data.sql.*;
import java.util.*; 

MySQL db;
Serial myPort;  // Create object from Serial class

int myaddr = 1;

int addr;
int numeric;
int ldr;
int heat;
int light;
int node = 1;
int nodec = 1;
long setTimer = 120000;
int commandtimer = 10000;
int nrofnodes = 2;
int timerflag = 0;
int commandflag = 0;
int x = 1;
int i = 0;

int addrset;
int tempmin;
int hummin;
int lightsw;
int heatsw;
int setflag;

String TIME;
String TIMESTAMP;
String room;

float temp;  
float hum;
long oldmillis;
long newmillis;
long oldcommandmillis;
long oldutchour;
long newutchour;
int utcflag = 0;
long utc;

char c;
String inData;
String[] list = new String[32];
String inDatapl;
String[] listpl = new String [32]; 

char utch = '@';
char sof = '#';
char dof = '/';
char plm = 'P';
char eof = '|';
char rf = '0';
char wf = '1';
char ack = '2';
char set = '3';
int flag;

void setup()
{
   size(640, 360);
   smooth();
   String portName = Serial.list()[2];
   myPort = new Serial(this, portName, 19200);
   myPort.buffer(64);
   myPort.bufferUntil(eof);
 
   String user     = "youruser";
   String pass     = "yourpass";
   String database = "ahap"; //DBName
   db = new MySQL( this, "localhost", database, user, pass );
}

void draw()
{
  newmillis = millis();
  newutchour = hour();
  //serial.Event(myPort);

  readSerial();
  if (newmillis - oldmillis > setTimer/(nrofnodes-1) || timerflag == 0 || commandflag == 1) // || commandflag == 1
  {
    commandflag = 0;
    timerflag = 1;
    writeSerial();
    oldmillis = millis();
  }
  if (millis() - oldcommandmillis > commandtimer/(nrofnodes-1))
  {
   oldcommandmillis = millis();
   writeSerialCommand();
  }
   if (newutchour != oldutchour || utcflag == 0)
  {  
    oldutchour = hour();
    utcflag = 1;
    calculateutc();
  }
  background(0);
  textSize(20);
  //int y=x+1;
  text("Addresse: " + node , 50, 30);
  text("Raum: " + room , 350, 30);
  textSize(16);
  text("Daten von: data-DB", 50, 50);
  text("Daten von: data_set-DB", 350 , 50);
  textSize(14);
  text("Temperatur: " + temp/10, 50, 80);
  text("Feuchtigkeit: " + hum/10, 50, 100);
  text("Heizung: " + heat, 50, 120);
  text("LDR: " + 0.1*ldr, 50, 140);
  text("Licht: " + light, 50, 160);
  text("letzter Kontakt: " + TIME, 50, 180);

  text("Msg OUT: " + sof + addrset + dof + myaddr + dof + wf + dof + tempmin + dof + hummin + dof + lightsw + dof + heatsw + eof, 50, 240);
  text("TIMEstamp: " + utch + hour() + dof + minute() + dof + second() + dof + day() + dof + month() + dof + year() + eof, 50, 280);
  text("Durchlauf " + i , 50, 220);
  text("Msg IN: #" + list[0] + dof + list[1] + dof + list[2] + dof + list[3] + dof + list[4] + dof + eof, 50, 260);
  text("Anzahl Nodes " + nrofnodes , 50, 300);
  text("Node " + node , 50, 320);

  text("soll Temperatur: " + tempmin, 350, 80);
  text("soll Feuchtigkeit: " + hummin, 350, 100);
  text("Heizung ein/aus: " + heatsw, 350, 120);
  text("Licht ein/aus: " + lightsw, 350, 140);
  text("eingestellt am: " + TIMESTAMP, 350, 180);
  //calculateutc();
  }

 void readSerial()
 {
   if (myPort.available() >0)
   {  delay(50);
      c = myPort.readChar();
      if ( c == sof )
      {
        inData = myPort.readStringUntil(eof);
        if(inData != null){
        list = split(inData, "/");
        print("Empfänger: ");
        println(list[0]);
        print("Sender: ");
        addr = int(list[1]);
        println(list[1]);
        print("Flag: ");
        println(list[2]);
        flag = int(list[2]);
        int listcount = list.length;
        print("Listenfelder: ");
        println(listcount);
     
        if (listcount > 8){
          //println("FLAG ACK ERKANNT");
          print("Temperatur: ");
          temp = int(list[3]);
          println(temp/10);
          print("Feuchtigkeit: ");
          hum = int(list[4]);
          println(hum/10);
          print("Heizung: ");
          heat = int(list[5]);
          println(heat);
          print("LDR: ");
          ldr = int(list[6]);
          println(0.1*ldr);
          print("Licht: ");
          light = int(list[7]);
          println(light);
          println(" ");
          sqlset();
          inData = null;
          }
                     
         if (listcount < 8){
             //println("FLAG SET ERKANNT");
             //inData = myPort.readStringUntil(eof);
             //if(inData != null){
             //list = split(inData, "/");
             print("Heizung: ");
             heat = int(list[3]);
             println(heat);
             print("Licht: ");
             light = int(list[4]);
             println(light);
             commandflag = 1;
             sqlupdate();
             inData = null;
           
             }
               
         }
        }
      }
   
 
    else {
      myPort.clear();
    }
    //delay(1);
    //myPort.clear();
 }

 void writeSerial()
 { println("write Serial");
   i= i+1;
    if (node <= nrofnodes)
   {
     node++;
   }
  if (node == nrofnodes + 1 || node == 0)
  {
     node = 2;
   }
   db.connect();
 if(db.connect() == true)
  {    
   db.query( "SELECT COUNT(*) FROM room_set" );
   db.next();
 
   nrofnodes = db.getInt(1);


   db.query( "SELECT  `TIME` FROM `data` WHERE addr=('%s') ORDER BY ID DESC LIMIT 1", node);
   db.next();
   TIME = db.getString("TIME");
 
   db.query( "SELECT  `room` FROM `room_set` WHERE addr=('%s')", node);
   db.next();
   room = db.getString("room");
 
   db.query( "SELECT  `addr`, `tempmin`, `hummin`, `lightsw`, `heatsw`, `TIME` FROM `data_set` WHERE addr=('%s') ORDER BY TIME DESC LIMIT 1", node);
   db.next();
   addrset = db.getInt("addr");
   tempmin = db.getInt("tempmin");
   hummin = db.getInt("hummin");
   lightsw = db.getInt("lightsw");
   heatsw = db.getInt("heatsw");
   TIMESTAMP = db.getString("TIME");

   myPort.write(char(sof));
   myPort.write(str(addrset));
   myPort.write(char(dof));
   myPort.write(str(myaddr));
   myPort.write(char(dof));
   myPort.write(str(rf));
   myPort.write(char(dof));
   myPort.write(str(tempmin));
   myPort.write(char(dof));
   myPort.write(str(hummin));
   myPort.write(char(dof));
   myPort.write(str(lightsw));
   myPort.write(char(dof));
   myPort.write(str(heatsw));
   myPort.write(char(eof));

  }
 db.close();
 
 }

 void writeSerialCommand()
 {
    println("write Serial Command");
  if (nodec <= nrofnodes)
   {
     nodec++;
   }
  if (nodec == nrofnodes + 1 || nodec == 0)
  {
     nodec = 2;
   }
  db.connect();
  if(db.connect() == true)
    {    
     db.query( "SELECT COUNT(*) FROM room_set" );
     db.next();
     nrofnodes = db.getInt(1);
   
     db.query( "SELECT  `addr`, `tempmin`, `hummin`, `lightsw`, `heatsw`, 'setflag', `TIME` FROM `data_set` WHERE addr=('%s') ORDER BY TIME DESC LIMIT 1", nodec);
     db.next();
     
       addrset = db.getInt("addr");
       tempmin = db.getInt("tempmin");
       hummin = db.getInt("hummin");
       lightsw = db.getInt("lightsw");
       heatsw = db.getInt("heatsw");
       //setflag = db.getInt("setflag");
       TIMESTAMP = db.getString("TIME");
     
     // if (setflag == 1){
       myPort.write(char(sof));
       myPort.write(str(addrset));
       myPort.write(char(dof));
       myPort.write(str(myaddr));
       myPort.write(char(dof));
       myPort.write(str(wf));
       myPort.write(char(dof));
       myPort.write(str(tempmin));
       myPort.write(char(dof));
       myPort.write(str(hummin));
       myPort.write(char(dof));
       myPort.write(str(lightsw));
       myPort.write(char(dof));
       myPort.write(str(heatsw));
       myPort.write(char(eof));
      // setflag = 0;
      //}
   
     db.close();
     if (x == nrofnodes)
       {
       x=1;
       }  
   }
 }  

 void sqlset()

 {
   db.connect();
   if(db.connect() == true)
  {
    db.query("INSERT INTO data (addr, temp, hum, ldr, heater, light) VALUES ('%s', '%s', '%s', '%s', '%s', '%s')",addr, temp/10, hum/10, ldr*0.1, heat, light);
    db.close();
  }
 }

void sqlupdate()

 {
   db.connect();
   if(db.connect() == true)
  {
    db.query("UPDATE data_set SET heatsw =%s, lightsw =%s, setflag = %s WHERE addr='%s' ", heat, light, setflag, addr);
    db.close();
  }
 }

 void calculateutc()
 {
   println("calculateUTC");
   delay(500);
   myPort.write(char(utch));
   myPort.write(str(hour()));
   myPort.write(char(dof));
   myPort.write(str(minute()));
   myPort.write(char(dof));
   myPort.write(str(second()));
   myPort.write(char(dof));
   myPort.write(str(day()));
   myPort.write(char(dof));
   myPort.write(str(month()));
   myPort.write(char(dof));
   myPort.write(str(year()));
   myPort.write(char(eof));
   delay(10);
   println("TimeSET");
   //myPort.clear();
 }

ArduinoHomeAutomationProject: The BridgeNode: PROTOTYPE & SKETCH (USE AT OWN RISK!!!)

The BridgeNode: PROTOTYPE & SKETCH (USE AT OWN RISK!!!)

The bridge is handling the data from the RaspberryPI SerialPort. I decided to take the USB Serial because there is no need to add a voltage divider (RPI 3,3V Logic, Arduino 5V Logic). The Incoming data is forwarded over the SoftwareSerial (RS485) while setting the DE Pin of the MAX485 high.

This is working for both directions. It is working at the moment, but i have to test it with more nodes to check for timing mismatches.

The Setup is an ArduinoNano + MAX485. 

THE CODE

#include <SoftwareSerial.h>
SoftwareSerial mySerial(2, 3); // RX, TX
void setup()
{
  Serial.begin(19200);
  mySerial.begin(19200);
}
void loop()
{  mySerial.listen();
  if (mySerial.available())
    Serial.write(mySerial.read());
    //delay(1);
  if (Serial.available())
    mySerial.write(Serial.read());
    delay(2);
}

TheSUN; Arduino powered wall clock; synced by AHAP

THESun; Arduino powered wall clock

Hi folks! A few days ago i decided to release my second Instructable about building an Arduino powered wall clock made of acrylic glass. Personally I am very satisfied with the result.
I attached some fotos here. The description itself can be found on Instructables.com just follow this LINK.

Startsequence

TheSUN in action

Fritzing

ArduinoHomeAutomationProject: The SensorNode; PART 2: PROTOTYPE THE HARDWARE

The SensorNode; PART 2: PROTOTYPE THE HARDWARE

In "The SenorNode; PART 1" we made a brief plan of our node and should be able to proceed by prototyping our hardware.

Let´s have a look at how I did it:

You will need the following parts to setup the Prototype:

• 1x Arduino nano or Arduino UNO
• 1x breadboard + wires
• 1x DHT22 + 4.7k pullup resistor
• 1x LDR + 10k resistor
• 2x LED + 2x 220Ohm resistor
• 2x pushbutton
• 1x I2C LCD (I´m using a I2C 16x2 LCD) + dupont wires (male - female)

You don´t need the Max485 chip + its 120Ohm resistor yet.

All you have to do is wiring everything to get a working prototype.

If you want to, you can try to make your own sketch for the prototype.

I will present and explain you my (already working) Arduino-sketch in PART 3.

Stay tuned!

ArduinoHomeAutomationProject: The SensorNode; PART 1: HARDWARE CONSIDERATIONS

THE SENSORNODE; PART 1: HARDWARE CONSIDERATIONS

Well, it´s time to get a little more concrete what the sensor node should do.

It should definitely measure the temperature, shouldn´t it?

In my case I also wanted to get some data about humidity and luminous intensity.

Further it should be possible to display the sensor readings and the time (if you want) to the user.

Now we defined what data we want to get from the environment, but we also want to interact with it.

My plan is to switch lights and electric radiators on and off.

The above mentioned things are enough to setup a prototype.

THE HARDWARE

We are going to use Arduino for our project, so we will prefer those sensors where an Arduino compatible library exists. We also should be aware of the sensor tolerance and its accuracy.

e.g.

•  a Sensor with a temperature range from 0 - 50°C and an accuracy of +/- 0,5°C will not make much sense for a wheaterstation. 
• a Sensor with a range from -40 - 90°C and an accuracy of +/- 2°C will not fit our needs.

I found those nice little DHT22 Sensors which have a temperature-range of -40 - 80°C with +/- 0,5°C and a humidity measuring range of 0 - 100% (accuracy +/-2%). You can get them for a few bucks on Aliexpress. We also need some 4.7k pull-up resistors for those sensors. There is a Arduinolibrary available on https://github.com/adafruit/DHT-sensor-library.

For measuring the luminous intensity we can take a LDR and a 10k Resistor for  the voltage divider.

We don´t need a library for that, because the sensor-reading with Arduino will be pretty much like "analogRead(PIN)" + some calculation for the interpretation of the data.

Further we will implement some switches or buttons which we are going to connect with a 10k resistor to the Arduino. These switches can be used to manually switch lights on and off.

Now let´s have a look at how we present the data to the user. Take a display which is already tested with Arduino and be aware that it has enough space to display all the data.

With a 16x2 LCD you possibly run out of space and have to switch the display modes, but you can give it a shot, it is well tested and there are library’s around.

In my opinion a good choice would be an 0,96" I2C OLED. They are small, they are cheap, and you have a really good resolution to display the data.

You can get the library’s here:

• LCD https://github.com/adafruit/LiquidCrystal
• OLED https://github.com/adafruit/Adafruit_SSD1306

Last but not least we should consider which type of transmission we will use. For easier code implementation I recommend something that supports the Serial UART bus of Arduino. 

I´m going to test the whole thing with MAX RS485 chips to build a long range RS485 bus-network (max. about 1000m via 2wire connection). If I can get some RF transceivers like "433Mhz Wireless Serial CC1101 Module" or "RF1100-232-TTL" I´m going to test them.