Tag: Arduino
Physical Android Notifier
by Dushyant on Nov.30, 2013, under Electronics
I wanted to create a simple notifier for my Android phone. Something that would blink whenever I have a missed call, or sms or whatsapp notification.
The hardware part was easy:
- Funduino Mini Pro
- Common Anode RGB LED
- Switch
- Bluetooth Breakout Board
Digital Pin-Art – WIP
by Dushyant on Nov.13, 2013, under Electronics
I’m planning to create a digital “pin-art” board – something similar to the photo below.

Source: http://cdn.visualnews.com/wp-content/uploads/2011/05/Lulu-Guinness-11.jpg
Standalone Temperature and Humidity Control
by Dushyant on Nov.11, 2013, under Electronics
Continuing from Standalone Arduino and Thermometer and Humidity Control, created a standalone thermometer and humidity control. Added the following features:
- Added a push-button to allow controlling the setpoint temperature
- Used the EEPROM library to save the setpoint temperature
- Enclosed everything in an extension cord with a power supply
- Left a socket to update programming as required
Charlieplexed LEDs with Arduino (Induino)
by Dushyant on Oct.26, 2013, under Electronics
Using ideas from:
Standalone Arduino
by Dushyant on Oct.14, 2013, under Electronics
Now that the circuit for my Temperature and Humidity Control is working – its time to create a standalone micro-controller circuit so that I can free up my Induino.
References:
http://arduino.cc/en/Tutorial/ArduinoToBreadboard
http://arduino.cc/en/Hacking/PinMapping168
http://www.instructables.com/id/The-RRRRRRRRRRBA-or-What-They-Dont-Teach-You-in-/step5/Some-Caveats/
Shopping List:
- Atmega 328P-PU (without bootloader)
- 16 MHz Crystal
- 2 x 22 pf capacitors
- LM 7805
- 1 uF + 10uF Electrolytic capacitors
- 10k Resistor
- General purpose PCB
All-in ~250 bucks. Had a 9V 1A power supply at home – so that was free. Needed a 9V for the relays that I had – otherwise you can use a 5V USB adapter that comes with most mobiles and gadgets. I have 8-10 lying at home 🙂
Wiring the Components:
Wire up the components as per the diagram below:
Burning the Bootloader:
- Connect your arduino to your computer using the USB cable.
- Select your board type and port from the Tools Menu
- Open the Arduino ISP sketch from examples
- Upload to your Arduino (clone)
For the Induino – you can modify the LED numbers as follows: Lines 49-51 in the code. LED_HB 13; LED_ERR 12; LED_PMODE 11;Edit: Just realised – pins 11, 12, 13 are used for actual programming and should not have LEDs attached to them.- This would allow you to use the in-built LEDs to show the bootloading process (purely optional)
- Select Tools->Board->Arduino Uno (the sources say use either Nano or Duemilanove – but Uno works just fine; I selected Uno so that I don’t have to keep changing the board every time I program my standalone kit)
- Select Tools->Programmer->Arduino as ISP
- Select Tools->Burn Bootloader
- Congrats – you have a working standalone arduino (albeit with some limitations)
You can disconnect the cables from your Arduino to the standalone board
 Uploading Sketches
Since our clone doesn’t have a USB-TTL interface, we have to use our arduino to program it. (this is one of the limitations :-))
- Remove the micro-controller from your Arduino (I’m trying to skip this step – so if anyone knows a better way – I’m all ears)
- Connect Rx pin to Pin 2 on the micro-controller
- Connect Tx pin to Pin 3 on the micro-controller
- Connect RST pin to Pin 1 on the micro-controller
- Connect power to the board (either through arduino or separate)
- Connect your arduino to the computer
- Upload sketch as usual
Thermometer and Humidity Control
by Dushyant on Oct.14, 2013, under Electronics
The first thing that came to my mind when I started microcontroller programming was to set an automatic room heating cum humidifier system.
First off – bought a DHT11 sensor module. Then went about setting up the circuit. Added the LCD to boot – to show the temperature and humidity.
Set up the circuit as follows:
Code as follows:
#include #include #define DHT11PIN 13 #define RELAY1 2 // Connect humidifier to Relay1 #define RELAY2 3 // Connect heater to Relay2 #define TEMP_SET 20.0 #define HUM_SET 35.0 dht11 DHT11; LiquidCrystal lcd(7, 8, 9, 10, 11, 12); void setup() { lcd.begin(16, 2); pinMode(DHT11PIN, INPUT); pinMode(RELAY1, OUTPUT); pinMode(RELAY2, OUTPUT); } void loop() { // put your main code here, to run repeatedly: int chk = DHT11.read(DHT11PIN); // Serial.print("Read sensor: "); switch (chk) { case DHTLIB_OK: // Serial.println("OK"); break; case DHTLIB_ERROR_CHECKSUM: // Serial.println("Checksum error"); break; case DHTLIB_ERROR_TIMEOUT: // Serial.println("Time out error"); break; default: lcd.println("Unknown error"); break; } lcd.setCursor(0, 0); lcd.print("Humidity: "); lcd.print((float)DHT11.humidity, 2); lcd.setCursor(0, 1); lcd.print("Temp: "); lcd.print((float)DHT11.temperature, 2); if(DHT11.humidity < 50){ digitalWrite(RELAY1, HIGH); lcd.print("H1"); } else { digitalWrite(RELAY1,LOW); // lcd.print("H0"); } if(DHT11.temperature < 25){ digitalWrite(RELAY2, HIGH); // lcd.print("T1"); } else { digitalWrite(RELAY2,LOW); lcd.print("T0"); } delay(900000); }
Worked like a charm – next steps:
- Add two buttons to change the temperature presets – save preset in EEPROM
- Create a standalone arduino so that I don’t have to give up my Induino for this small project