This is an old revision of the document!
Description: The project consists of an alarm clock that, on ringing, will diplay a series of math questions and the user will have to correcty answer three in a row for the alarm to stop. Alternatively, if math proves to be too difficult at the time, the user can stop the alarm by yelling at it with sufficient volume.
Purpose: The purpose of the device is to make sure that the user is actually awake when turning off the alarm.
Utility: It's inteded to be usefull for people who frequently turn off their morning alarm and imediately fall back asleep.
Normal state Device displays current time. The microcontroller reads the time from the RTC module and displays it on the LCD. From this state the user can press the 1 key to open settings.
Settings menu Time is replaces by settings menu. The LCD will show on the top row the name of a setting (ex: “set alarm”) and on the bottom row the options “1back 2ok 3next”. If the user presses 1 the clock goes back to normal state, if they press 2 the bottom row is replaced with input options for the setting in question” and if they press 3 the top row will display next setting. The possible settings are the following:
Alarm time When current time reaches the value set for the alarm, the microcontroller will send the alarm tone signal to the buzzer for it to ring. On the display, the current time will be replaced by a math question generated by the microcontroller. The user will be able to enter answer trough keypad and the microcontroller will keep track of the number of consecutive correct anwers. If this number reaches 3, the alarm will turn off and the clock will go back to normal state.
At the same time, if ragequit mode is enabled, the microcontroller will check the inputs from the noise sensor and turn the alarm off if a loud enough sound was detected.
| No | Component | Role |
|---|---|---|
| 1 | atmega328p-xPlained Mini | microcontroller |
| 2 | 16×2 LCD | displays time + math questions + settings menu |
| 3 | 4×4 Keypad | user input for settings and question answers |
| 4 | Noise Sensor | detects if sound exceeds a treshold (user yelled loud enough) |
| 5 | Passive Buzzer | produces alarm sound |
| 6 | RTC Module | keeps time |
| 7 | LED (x2) | display certain settings (1 for showing if an alarm time is set, 1 for showing if ragequiting mode is enabled) |
| 8 | 220ohmRezistors (x2) | creating the LED circuits |
| 9 | Breadboard | connecting other components |
| 10 | Dunport wires (various types) | connecting other components |
| No | Component | component pin | microcontroller pin |
|---|---|---|---|
| 1 | LCD | SDA | PC4 |
| SCL | PC5 | ||
| VCC | 5V | ||
| GND | GND | ||
| 2 | Keypad | SDO | PB0 |
| SCL | PB1 | ||
| VCC | 5V | ||
| GND | GND | ||
| 4 | Noise Sensor | OUT | PD4 |
| VCC | 5V | ||
| GND | GND | ||
| 5 | Passive Buzzer | + | PD5 |
| - | GND | ||
| 6 | RTC Module | SDA | PC4 |
| SCL | PC5 | ||
| VCC | 5V | ||
| GND | GND | ||
| 7 | LED1 | + | PD2 |
| - | GND | ||
| 8 | LED2 | + | PD3 |
| - | GND |
Electrical diagram - in red are VCC connections - in black are GND connections - in blue are I2C SCL connections - in orange are I2C SDA connections - in green are other types of input/output
I connected the I2C devices(RTC and LCD display) to the pins allocated to I2C communication, PC4 and PC5.
While the keypad has the pins named as for the I2C protocol, I found by reading its linked library that it actually doesn't use I2C exactly, but another way of outputing key presses trough only 2 pins so i didn't connect it to the I2C bus.
The passive buzzer is connected to a PWM pin in order to receive the square signals for the alarm tone.
The rest of the components are conencted to standard I/O ports.
Keypad input showcase In this picture is the circuit with only the keypad. Here, I pressed a few buttons on the keypad and this input was received by the microcontroller and printed on the computer screen using USART.
Fişierele se încarcă pe wiki folosind facilitatea Add Images or other files. Namespace-ul în care se încarcă fişierele este de tipul :pm:prj20??:c? sau :pm:prj20??:c?:nume_student (dacă este cazul). Exemplu: Dumitru Alin, 331CC → :pm:prj2009:cc:dumitru_alin.