PBM: Requirements and specifications

On this first chapter of Pic Bytes Micro, we will write down some specs and requirements to have an idea of how the final system will look like. This will also help us to select the components and divide the whole project into small tasks.

So with everything said and done, let's start:

Screen: The screen will be a handmade 16x10 LEDs matrix. With the final design in PCB, SMD LEDs with metric 0805 are going to be used, but for the prototyping stage, surface mount 3mm LEDs are the choice. Finally, to drive the screen, we will use 28 transistors that will withstand a maximum current of 200mA. We will see more details once it is done.

PIC18F45k50: 8-bit Microcontroller with tons of available information on the internet. It is available in 20, 40 and 44 pins package sizes. We also have different configurations: PDIP for the prototyping stage and TQFP package for the final PCB. Some features are: USB 2.0 compliant, 36 Input/Output pins, 32K bytes Flash memory, 2048 Bytes of SRAM and 256 bytes of EEPROM.

Sound: A buzzer driven by a transistor and a PWM signal from the PIC. Having into account that the chosen PIC is not able to create two PWM at a time with different frequency, the sound will be mono.

Games: The console should have several games loaded in memory. However, due to the screen limitations, the games are going to be very simple: Snake, Tetris, Arkanoid...

Battery: A rechargeable battery and at least one hour of a lifetime is expected. The battery will charge through a USB port (MicroUSB or type C). For this reason, power consumption is a critical aspect of the design.

Simple Parts: The console should be constructed with simple and cheap parts. There won't be external sound chips, LEDs drivers or any other fancy part. The only non-general part is the power charger IC used for the battery. 

Budget: This is a project intended to be as cheap as possible. The budget is set to 30€, including all the components and the PCB.