ATMega328 I2C Base Board

In this planned to be a short post, I will quickly take a look at a scaled-down version of the ESP-12E I2C Base Board. This one in particular has only two slots, without the dedicated ESP-Card slot.

The main reason for this PCB is that the original version was designed for easy prototyping and projects where enclosure space will not be an issue. This is especially true in the case of the actual project that this will be used in, as there are quite a lot of other, very bulky components, that all need to be fitted into a relatively small enclosure.

What is on the Board?

The board contains two 2×20 Pin Male Header slots, providing 12v, 3v, Ground and access to the I2C bus, as well as additional GPIO’s as provided by the module plugged into the slot. I have also decided to provide breakout access to these IO’s on the actual PCB.

This is a feature that was not yet implemented on the original prototype.
Additional Ground connections, as well as an I2C expansion port, used to interconnect to other Base Card modules were also added.

It is also important to note that the I2C bus is powered by 3v. Interface modules should take this into consideration ( mine does ).

Power is provided by an MP1584 Buck converter module.

What has Atmega328p to do with it?

I called it ATMega I2C Base Module due to the fact that I plan to design a custom ATmega328P prototype card specifically for this unit, with all possible IOs broken out to header pins. I found that this style of prototyping suits my development cycle quite well, as I really dislike using breadboards and wires.

As I try to reuse a certain PCB or design it to be as general purpose as possible, having access to ready-made modules that can be slotted into a base and programmed, really saves a lot of time.



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