|Author:||Sébastien Lelong, The SirBot Project, 2005|
|Revision: 409||Initial creation|
|Revision: 441||Convert to REST|
|$Revision: 538 $||include 16F88: changed doc and diagrams|
The Main Board is the central electronic board of the SirBot Project. It contains a microcontroller which permits to control every SirBot Modules (external boards).
The version of this board has a integrated RS232 module for communication capabilities via the serial port.
Currently, two microcontrollers can be used, with minor modifications in the assembly: PIC 1F628 and PIC 16F88. This only difference is about connecting the UART module. PIC 16F88 is a better choice, as it has more memory, ADC (analog-to-digital) and mostly it can be programmed using a bootloader (such as TinyBootloader, fully tested, see python version pytbl.py in the 3rd party SirBot distrib).
The Main Board corresponds to the following diagram (here for a 16F628):
For the RS232 module, we have the following diagram:
The following pictures show pin diagrams for 16F628 and 16F88 microcontrollers, with differences about UART pins.
|R1, R2||Resistances 1|
|C3, C4||Condenser 22pF|
|C5, ..., C9||Condenser 1µF|
|D||Diode 1N4001 or 1N4004|
|Q||Quartz 20MHz (or 4/10 Mhz, preferably 20MHz)|
|REG||Voltage regulator 7805|
|CI1||Microchip PIC 16F628 or PIC 16F88|
|J||Power supply connector 2.5mm|
|K||26 pins connector|
|K2||RS232 connector (male)|
|Note:||This board needs a (at least) 9V/500mA power supply, not regulated (there is a voltage regulator on the board).|
The Main Board provides a bus connection (via connector K). Every external modules have this connector so they can be plugged-in and controlled by the Main Board. hus, this bus provides communication capabilities between every boards and must respect the following specifications:
- The connector has 26 pins.
- 18 pins are used to have access to every pin of the PIC 16F628
- 2 pins are used to provide power supply to other modules.
- So, 6 pins aren't used yet
The connection diagram is the following:
The following pictures show the implementation of the components on a board (with holes) and the reverse side of the board. Layout differences are shown in red whether 16F88 or 16F628 is used.
The reverse side is the same: