UC Trainer Board Questions and Answers:

1) How to place a MCU into the ZIF socket?

The MCU should be placed against the top of the ZIF socket (the end closest to the moveable arm.
First, open the movable closure elements by lifting the ZIF socket arm.
Second, place the MCU into the socket with the notch against the top (pin 1 upper left corner). Do NOT add any pressure or hold a position of the chip.
Third, close the movable closure elements by lowering the ZIF socket arm.

2) How to use the uC Trainer to program different MCUs?

The PIC Trainer has the ability to program many different 18, 28, and 40 Pin DIP package Microchip MCUs. There are two DIP switches to select different MCU family members for the program and evaluation operations. See S1 & S4 Settings for more detail uses of the S1 and S4 DIP switch settings. If you are using the Rev3 trainer and want to use it with Arduino Module or TI Tiva C Series LaunchPad/ARM M4, then set all switches on S1, S4, S5, & S6 to the OFF positions.

3) What are the functions of the Package Selection S1 DIP settings?

The S1 DIP switch (10-position switch) is used to select different MCU package for the following:

• S1 DIP switch 1-5 should be OFF and 6-10 should be ON for 18-pin package MCU such as PIC16F84A or PIC16F88.
• S1 DIP switch 1-5 should be ON and 6-10 should be OFF for 28-pin or 40-pin package MCU such as PIC18F2550 or PIC16F877A.

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4) What are the functions of the Package Selection S4 DIP settings?

The S4 DIP switch (2-position switch) is used to connect power, ground, and programming clock and data signals to the appropriate MCU for programming purposes. The following are the setup settings for programming and operation/evaluation:

Programming:

• S4 DIP switch: 1 should be OFF and 2 should be ON for 18-pin package MCU such as PIC16F84A or PIC16F88.
• S4 DIP switch: 1 should be ON and 2 should be OFF for 28- or 40-pin package MCU such as PIC18F2550 or PIC16F877A.

5) What to do if PICKit2 does not recognize the MCU in the ZIF socket?

• Always provide the power to the trainer first, then plug in the USB for programming and PC to trainer board communication.
• Press and hold the RESET push button (S2 for 18-pin MCU, S3 for 28-pin or 40-pin MCU), click on Tools under the main menu, then select Check Communication.
• Never build or change the interface jumper wires with the power on. If there is a momentary direct short on the interface that may cause the erase memory of the on board PIC18F2550 MCU. If this happen contact ODU faculty or call 757-683-4606 immediately.

If the PICkit2 still cannot detect the MCU, there may be several possibilities:

1. The S1 and/or S4 switch settings were wrong.
• Solution: change the S1 and S4 switch settings.
2. The wall mount power supply was not providing 15V power.
• Solution: replace with a known good power supply.
3. There may be old source code in the MCU that was using RB6 and RB7 for designed I/O operation.
• Solution: press and hold the RESET switch (S2 for 18 Pin MCU, S3 for 28 Pin or 40 Pin MCU) and repeat the programming operation.

6) What to do if the heat sink on IC2: LM7805 or IC3: LM7812 becomes too hot?

It is most likely that there is a direct short or very low resistance on the trainer board or user's interface between +5V DC or +1 2V DC and Gnd.

Solution: Unplug the power immediately and have the issue resolved before using the trainer board.

7) How to use the breadboard to build additional interface circuitry?

The Red and Blue vertical stripes on both sides of the breadboard have no connection to anything by default. The user needs to install jumper wires from X27 connectors to the bread board to bring +5V and Gnd to the breadboard. There may be a discontinuity in the RED and BLUE connectors at the midpoint on the breadboard. If the gap is wider at the midpoint than elsewhere on row (it depends on the manufacture of the breadboard), the user must install jumper wires to link the two halves. It would be a good idea to perform a continuity check here even if there isn't a gap just to make sure. This is a common source of problems! The main area is just the same as a regular breadboard and is the area where the IC or other components may be placed for experimenting or evaluation activities.

8) What will be the right wall mount power supply to use with the PIC Trainer?

The wall mount power supply can be either AC or DC but it must provide at 15V (AC or DC) to be sufficient to be used for PC USB communications.

9) What are the appropriate jumper wires to use with the PIC Trainer?

Use the pre-manufactured jumper wires that come with the trainer board. The recommended jumper wire gauge is 26 or CAT 5 or CAT6 cable wire that is used for PC Ethernet communication. Note: Be sure to check on the continuity of all the pre-manufactured jumper wires for any defect.

10) What is the function of the Red LED2?

The LED2 (RED) is an indication to the +5V is available on the trainer board. This does not mean the +12V is there for PC USB communications. However, the LED will light with only a couple of volts from the +5V supply, so the supply should be checked with a voltmeter to be sure it is operating properly.

11) What is the function of the Yellow LED1?

The LED1 (YELLOW) is an indication of the communication activities between the PC USB and the trainer board.

12) Which USB (X1 or X3) is to be used for MCU programming?

Only X1 is used for PC USB communication for programming purposes.

13) What is the function/purpose of the X3 USB connector?

X3 is used for USB communication with an MCU that has a USB hardware block (such as PIC18F2550) for any USB exercises in MCU level designs. The user must have the designed codes in this target MCU for evaluation.

14) What is the function/purpose of the X2: DB9 connector?

The X2: DB9 is used for serial RS232 communications with a PC or other device. The interfaces are to be made on X5 that will convert between standard TTL and RS232 signals for in and out.

15) What is the function/purpose of the SV1:14-Pin IDC Socket?

The SV1 is used to connect a 14-pin LCD module interface. When connected to an LCD module via a ribbon cable, the LCD module pins are connected to the X29 connector posts and the interface can be made directly between MCU I/Os posts ports or via the breadboard connections.

Note: If the LCD module requires negative reference voltage on its Vo (Pin #3 on the LCD and Pin #12 on X29 Interface Connector). The negative reference voltage is available on Pin #2 on X44 Interface Connector.

16) What is the function/purpose of the SV2: 8-Pin Straight Socket?

The SV2 is used for interfacing with a 3*4 or 4*4 matrix keypad. When connected, every keypad pin is pulled up to +5V through the on-board 10KΩ resisters.

The Interface pins are brought to the X4 connector posts and the interface can be made directly between MCU I/O ports or via the breadboard connections.

17) What is the function/purpose of all the X Sockets surrounding the breadboard?

The X socket connector posts are meant for jumper wire Interface Connections to fit any experimentation or evaluation needs. Please see Item #9 for jumper wire recommendation.

18) What is the function/purpose of all the X Green Terminal Blocks on the side of the PIC Trainer?

The green terminal blocks on the side of the trainer board are used for high power connections for motor (DC or Stepper) drive exercises. The motor power and trainer board system power are isolated via optical isolators. Using the terminal blocks will prevent electrical noises generated by running of the motors from getting into the trainer board power supplies. The recommended power to the terminal blocks is 2A.