Circuit Description and Stripboard Layout

The layout of the final design in stripboard form is shown below:

The function of each of the links is as follows:

Link A can be used to bridge power originating from the programming or console port so that it can be used to power the MCU during development. An additional link is also required in order to obtain power from the console connector on the Microbridge when plugged into the ICSP port of the MCU. (see picture below)

Link B can be used to select either 3.3V or 5V I2C bus power.

Link C is used to locally terminate the I2C bus, the termination is made to either 3.3V or 5V depending on the selection made by Link B.

All the connection points on the board are 0.1" strip pins with the exception of the RTC socket, this provides the facility to connect a clock module and also provide access to the I2C bus for further expansion.

As Built

The image below shows the GPC configured for programing via the ICSP port in order to burn the MicroMite operating system into the device.

Here the Micromite is connected to the Microbrige for development.

 Finally a RTC has been installed so that it can be used by the MicroMite device. The blue links are set to bridge power from the console port, set the I2C bus to 3.3V and include local bus termination.