So for the next microcomputer with a keyboard, we will use a PCB to connect all the components. And it is the first step, to create a list of the components.

We will use esp32 as the microcontroller, we know it well and it is quite a computer powerful. And it has one great advance, it starts up in a few seconds. We don´t want to wait minutes for a computer to start up, and we prefer to shut down the device to save battery life.

The screen is a common screen with a good resolution, 320x240, colorful, and an SPI interface. We saw a module with a touchpad and SD card so we go that way. 

The buttons are normal switches. 

The other problem is the battery, we are not sure what is the right way, so we uses two ways, AAA batteries, and lipo. The first only needs a  boost-converter to go from 2.4-3 Volts to 3.3. The lipo uses a battery charger, and a buck-boost converter, because lipo go from 4.7 volts to 3.3.

And we used Kicad to develop the PCB, and in a few weeks we got the first prototype. The screen was placed in reverse, and we need 4 resistance to pull up 4 IO pins that do not have internal resistance.

This second prototype works great, and we mount the components in there.

And it works !!!!!!!!!

Next step the software.