Design a universal PCB for Arduino uno

For starters, the heart of this design will be an Arduino nano. It's a fairly small, powerful, and low-power microcontroller, which is important for a battery-powered system. It is also very inexpensive. It will be surrounded by a maximum of 4 peripherals connected in I2C, a micro-SD card reader, and will be powered by a 9v battery. The design was created on EasyEDA.

Design a universal PCB for Arduino uno

The SD card reader will be used to save the data collected on the 4 sensors.

This printed circuit can be used for all kinds of autonomous projects, thanks to its I2C ports which will adapt to all the desired modules (BMP280 pressure sensor, GY-521 accelerometer, OLED screen, etc.)

We will start with the schematic part. We therefore place the Arduino nano, the pins for the 4 I2C devices, as well as the location for the SD card reader and the screw terminal for the battery.

Then, we connect the different pins for the desired connections:

SCL to A4

SDA to A5

CS to D10

MOSI to D11

MISO to D12

CLK to D13

Then, once the schematic part is finished, we can start editing the PCB. Be careful to check the orientation of your components so they don't jam together when soldering.

So we start by placing the Arduino Nano, then the 4 I2C ports around it.

For the size of the PCB, we will adapt in order to minimize the space, once all the components are placed.

We can now place the SD card reader, as well as the battery connector.

Once all the components are in place, we can start optimizing the space to reduce the size of the PCB.

To do this, bring the components as close as possible using their outlines, and being careful to keep a slight space to overcome measurement problems. At the same time, you can move the pin names around so they don't interfere with the pins.

Now is the time to draw the connections (the ones we made in the schematic step). Currently, these connections are only represented by lines between the components, but we will use the AutoRouter built into EasyEDA, which will automatically trace and optimize the connections. So we come up with a 2-layer design.

Next, we will ask the software to add a GND zone between and around each copper route, to facilitate routing, and avoid creating an additional connection for the GND (it will therefore be accessible everywhere).

So we're done. We can use the 3D tool to visualize our PCB and notice any errors on our circuit.

This design has been thought to fit in a bag, in a box, or in any small compartment. 

The presence of the 4 I2C ports makes its uses unlimited, automotive, gardening, model aircraft, smart-home, etc. They can accommodate sensors of all kinds: voltage, current, pressure, luminosity, accelerometer, humidity, temperature, etc.

The design can also be adapted to accommodate a connected microcontroller such as an ESP8266, a WEMOS D1 MINI, an ESP01, to create connected autonomous systems and integrate it into a complete ecosystem.

hope you all will like this board!

happy designing!

you can get your pcb done from here

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