This week we'll start talking about hardware, as promised.
To start our electronic design we think about what resources we have available, what we want to do and we can really do. First we analyze the main part of the project, the microcontroller. This line belongs to the low power of Texas Instruments, which is also the cheapest line, a thousand units of the computer cost U$ 1.35, being the economic line the number of these ports and functions are also scarce.
What we have in mind is to make maximum use of all features supported by only 14 micro-door, causing him to communicate with buttons, LCD display and analog signal devices. Based on these components you can use the ports I / O to send and receive data, the ability to use serial communication on the available ports, analog signal reception doors with A / D converter.
A characteristic that can be noted are the two main roads, instead of one.In these the CPU sends and receives data from the Flash memory and RAM, A / D Converter, Watchdog Timer, SPI interface, I / O ports and the unique JTAG Interface (essential mechanism for the "debug" of embedded systems) due to two-way protocol (Spy-Bi-Wire). It is also an internal clock associated with the CPU, in addition, there is a protection against "brownout" (undervoltage).
So we have the most resources available in project economically cheap to obtain a final product that can be the basis for production to the market. A product of high consumption, low cost and with a fair level of associated electronics would be a watch, it has buttons, LCD display, temperature sensor and external timer, so we have to build a viable device.
Thus, in the coming weeks we will be studying and designing our watch, bye.