• The Motherboard

    by  • 21. Mai 2018 • Technik

    Motherboard description and “Eagle” files

    First download the “Eagle”-file (see below) and then read the description.

    • On the board there are two microcontrollers: PIC16F1517/9 and PIC16F876(A). The 1517 is the Master, who controls the motion of the robot. The 1517 has 4kB and the 1519 8kB programm space. If you want to use the board for „Maze“, you have to put the 1519 on the board, for creating a map. The main function of the 876 is to control the LCD display. But, if needed, you could use him as an I2C device with the address 0x20. Several pins are unused.
    • There are a lot of pads, you have to mount a male connector. For mounting them its easier to design pads than jumper. If you want to solder on jumper holes its difficult, because they are falling down if you turn the board. The pads are a little bit smaler, it isnt easy to mount them, but its very easy to solder them.
    • There are four sticks to put the supply to the board, +5V and GND and on both sides sticks to stabilise the female connector.
    • There are about 13 triple connectors for analog sensors or servos or encoder or others. They are builded all the same: near to the PIC16F1517/9 is the input or output, in the middle is +5V and at the outback there is the GND pin.
    • There are two four-pin-connectors to link two ultrasonic sensors, incl. power supply.
    • You could programm the two PICs over the 5-Pin-Connectors where VPP-pin is marked with a rectangular dot.
    • The output for the LCD is constructed to put the LCD right on. For to dimm the lights there is a potentiometer called „LCD light“ and one is for to turn on the contrast of the letters.
    • Three 4-pin-connectors and one 2-pin-connector are mounted near the 16F876A to connect I2C devices. The 4-pin-connectors have a power supply for the devices.
    • Two push buttons on the top of each PIC are to reset them. Two other are for giving the PICs a signal (S4 and S5). S4 is normally high, S5 n.l.
    • The schottky diodes may be for example „B130“. They are for disconnecting the board from the programmer, so that it wont supply the board.
    • There is a list for a possible pin configuration for both, „Maze“ and „Line“

    “Eagle” file:

    ICSP_16F1517a16F876A_1_ready

    Suggestion for the pins of PIC16F1517/9, “Line” and “Maze”:

    Pins_1517_9_Board

    The basic version of the source codes (Libraries for using the motherboard):

    The “Master” (PIC16F1517/9):

    1519_PGM.X

    The “Slave” (PIC16F876A):

    Slave.X