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Eagle CAD: 1. Expansion Schematic
Resources Allocated
Eagle CAD: 2. Expansion
PCB
BOM
(Bill of Materials)
ATmega328P Main Board Top
ATmega328P Main Board Bottom
ATmega328P Expansion Board
 |
Weather Inside
Ok, so you've built the base Aduino board; now
what? How about building an expansion module that fits on top
of the base board? The one being designed here serves as a
sensor board for logging the current weather stats, and the
program/sketch that runs it is called "Weather Inside".
The uC Expansion Board
The expansion board fits on top of the base
ATmega328P uC board. All
digital, analog and power connections are passed from the base board
female headers to the expansion board.
Features
The
expansion board has the following features some of which are
individual electronic components while the others are small SMT-based
boards:
|
Feature |
Product ID |
Digital/Analog Pins |
I2C Address or Comments |
|
Banggood 1.3" OLED (128x64)
Other 1.3" OLED (128x64)
|
1067874
AliExpress
|
I2C (A5 SCL, A4 SDA) |
Banggood
Geekcreit 4-pin I2C 128 x 64 monocolour OLED display
- I2C address 0x3C or 0x3D
- No Reset pin
needed
- Uses SSD1306 display driver
- Pinout: GND, VCC, SCL, SDA
- Round mounting holes
Other Chinese 4-pin I2C 128 x 64 monochrome OLED
displays
- I2C address 0x3C or 0x3D
- No Reset pin
needed
- Uses SH1106 display driver
- Pinout: VCC, GND, SCL, SDA
- Oblong mounting holes |
|
Adafruit BME280 sensor |
2652 |
I2C (A5 SCL, A4
SDA) |
Temp, humidity, BP sensor. I2C address 0x77 or 0x76. |
|
Adafruit RGB LED |
159 |
A1, A2, A3 |
Diffused tri-colour 5mm, 20mA average current
draw for all 3 colours, Brightness: Red 500mcd, green
600mcd, blue 300 mcd. |
| Sparkfun Buzzer circuit |
7950 |
D4 |
Complete driver circuit for the
piezo buzzer/speaker. Can be used to play tones, melodies,
etc. |
| Tactile momentary
switches |
367 |
D5, D6, D7 |
3 switches are available, perhaps
for menu item selection in your software design? |
|
LDR: light dependent resistor |
SEN-09088 |
D3 |
An LDR is a resistor that changes
its resistive value (in ohms)
depending on much light is shining on its face.
You could use it to determine if it's night time to turn off
the display? |
| Banggood PIR motion
sensor |
1885169 |
D2 |
Motion sensor with a range of about
6 feet (2m). |
| Adafruit Micro SD Card module |
254 |
SPI (D10, D11, D12, D13) and A0 |
Due to lack of space on the
expansion board, this module
can be attached to the bottom of the ATmega328P base board |
| USB/FTDI connector |
FT232RL |
D0 RX, D1 TX |
Connect the USB/FTDI module to the
base board connector to program it via the Arduino IDE. |
| Free GPIO resources? |
|
D8, D9 |
|
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