Electronic Circuits and Tutorials
Course in PIC Microcontrollers Programming

Let's go online

Author: Prof. Dr. Marco Gottardo
Email:  ad.noctis@gmail.com

Prof. Dr. Marco Gottardo

This tutorial is dedicated to all the lucky owners of a copy of the PIC Micro-GT versatile IDEO to all those who want to assemble one.

You will be able to flash the PIC using the programmer and then a few minutes devoted to reading and led the execution of tests.

Good work and good luck to all.

Marco Gottardo.

Dedicated software or usable.

We are developing a platform that in analogy to the official home of Microchip 's MP-Lab, will be called MG-Lab. Pending released the first beta release we use the standard tools taking advantage of the compatibility of our project with the famous 8076. This program is using the PICPROG2009 easily found around.

click here

UserFiles / ad.noctis / Setup.zip

The MG-Lab platform integrates a compiler "ANSI C" that will allow the use of libraries "C16" totally compatible with the product of "Hitech" normally integrated in Mp-Lab

Serial cable connection

The Micro-IDE is versatile connected GT PIC to a PC via a serial cable to the RS232 port of a PC (where available), otherwise just get a USB-RS232 adapter, I personally use a mahnattan and I never found malfunction. In case of direct connection to the port is important for both IBM compatible and supports the 16550 UART, if you have doubts try it anyway, nothing will happen to your PC.

You must know that the circuitry placed immediately after the connector converts RS232 protocol in a emulated I2C mode handshake.

The UART (universal synchronous one transmitter receiver), operating with TTL logic level and delegates to the operations of parity checking, synchronization, timing data, etc., are within the PIC that you inserted into the ZIF socket, while the GT-PIC Micro residents are the two integrated dealing with the piloting of the transmission line and to the translation of the levels, given that on the external cables will be present in bipolar voltages well-12V.

The real driver is the classic MAX232. which has for example the important role to transform into unipolar serial signals that in RS232C is bipolar, as well as to carry it from one level of 12V to a level of 5V, vice versa when the signal arrives in the form TTL by PIC and wants to go toward the PCs.

The cable used is simply passing through, or configuarto pin to pin.

An important trick is to buy the Cannon Plug connector SUBD 9 pin miniature type compatible with what you have already mounted on Micro-GT, and bearing in mind that issues of standards, on the PC that is always of the "male". A small study, without going too off topic, saying that you can bring in transmission systems communicating you're ready to distinguish between DCE (data communication equipment) and DTE (data terminal equipment). standards for the DCE (PC side) is always male, we see that the pins appear, while in the driven device (DCE, such as were the old serial mouse) the cross connector is always female.

Even if you are not forced to do so, I recommend you install the connector on the Micro-GT Cannon SUBD 9 pin female, and then the cable will be connected to a female and a male PC side to connect to your programmer Micro-GT. If you follow this you will consiglo correctly set even if you're in a portable USB drive and use the USB/RS232 that I mentioned earlier.

Here is the diagram of how to wire the connector if you have not already available through cable (serial extension).

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Connecting and testing first
 

Before turning the system to make sure that nothing has been housed in TEXTOOL PIC, then connect the cable to the serial port of the computer or the converter USB/RS232 for example if we are working with a PC without this cross connector.
 

We feed the device bringing tension to terminal X1 (the left of the serial). To do this, you will have ample room for maneuver because it is designed to be fed either in continuous alternating. Invertirete If the DC voltage to 15 volts to terminal X1-course nothing happens, turn on properly. Ultimately, if you have a stark transformer secondary rms voltage measured at 12V, hold fast to X1 and everything works, everything works as well if you stick an old laptop power supply, voltage greater than or equal to 15 volts. Do not go down below this voltage because the PIC to be flashed, if no mode is enabled at low voltage via software, they need a voltage of 13.2 volts which we obtain placing in series to the ground pin of the voltage regulator two 1N4148 diode types. These diodes being placed in the PCB right behind the controller to the left (to 12V) are not visible in the original photos.

Connected to the power supply the POWER LED lights up, indicating that are present 12v and given that the second regulator is in cascade, if this is operative, even the 5Volt necessary for the feeding of the PIC.

In the top view can be seen better the position of the LED and the fact that being supplied is on.

At this point we are ready to launch the picprog2009, obviously after installing it on your PC, and bearing in mind that this is a makeshift, though fully functional, until they will release the first beta release of the integrated planning system MG- Lab

 

Roughly speaking, the circuit section that deals with the programming, unless the mode of connection that is specific to the supervisor of our Micro-GT, resembles that of the product for which it was written picprog2009, so that will give the impression of being interfaced to the system expects that, by rotating the same diagnostic routines.

We compare what he expects to see this software "alien" with what is actually in the field, so you also do a preliminary idea of how we will develop graphical interfaces of the MG-Lab.

Button click on the icon "on pcb" which brings us in diagnosis, after selecting the microcontroller of our interest, for the moment the 16F877A:

 

 

It is projected on a screen that represents the native system for this software, but in our version will show the layout of the PIC Micro-GT.

On this layout we see some things of interest, primarily the LED status indicator and data voltages.

 

These LEDs have a nearly direct correspondence with those in the GT PIC Micro-IDE versatile as you can see in the picture below.

 

Lying on the left side of the tab orientation does not coincide, are in fact arranged vertically. From top to bottom are DVPP (green), DPGC (red), DPGD (red).

The diagnostics can be run in two different ways:

  • Clicking the mouse on the LED monitor that you see drawn. Those in the field respond the same way.
  • Launching the routine cyclical automatic leds, which I must respond in real time on the Micro-GT. This routine is indicated on the button to click with the name "data line test", which head the flow of data to and from the PIC. This test but performed exclusively without the PIC into the socket, otherwise it might break.

Entered in the diagnostic, as mentioned see the board layout in our software will be that of Micro-GT, but now focus attention to the fact that, having set the controller of interest in the above screen, the program suggests where to place the loose wires of the connector ICSP (in circuit serial programming) letting us see the physical layout. Obviously if we change the new microcontroller is suggested proper disposition of same.

 

 

The information in this imagining is important from an operational standpoint because of three columns shows the pinout of the cross connector ICSP, ZIF socket, or TEXTOOL, and real-PIC, so we are led to the errors of connection. Everything suggests this picture is also valid for the Micro-GT, and will be reported the same in our software.

 

Some pictures below show the Coretta construction and ICSP cable Plug connector and its position in the "PIC Micro-GT," These are two connectors, shown in the photo above, a clear silk screen them out. Make sure the pin 1 is left and must match the brown wire.

ICSP cable dedicated to the Micro-GT, the other side and leave it free simply insert assiome to the processor pins in the socket. Again I urge you to respect the colors.

A clear indication of how to enter the co n t net hours ICSP1 ICSP connector in the card, there is also a second way ISCP2 that for the moment we do not use.

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Once launched, diagnostics, well if you have assembled the board, or at least the part about communicating with the PC, the automatic switch to video sequences go hand pa s so real with the LEDs in the field. You are now ready to program the PIC in a real way after you have tested the operation of your files. Hex using realpic simulator, as explained in the first part of this online course. Those who had not read it yet do it now.

Movie of the tests and data communication line

Nle movie possimo see the PIC Micro-GT connected to my netbook via a USB serial adapter. For the moment the software I use for testing is the picprog2009 can also be used for the PIC flash explained as above. For each specific PIC card is configured using colored threads to attach to the cross connector Plug connector ICSP, while on the side of free advice pinzandoli simply connect the wires together to the microcontroller when the housing TEXTOOL. It 's easier and effective, or use of the individual female and streem collegativi the correct pin for direct I / O which  I refer you back to the wiring diagram. If you see this error message means you did something wrong during assembly or that or the cables used are not suitable. could also mean that the PC port to which you linked does not work

Click on the link below to download the movie in "3gp" test of communication.

UserFiles / ad.noctis / File / Micro-GT 20Test%% 20com.zip

 

Proposed exercise

As the first full experience I invite you to upload files. Hex LED flashing done in the first half of the tutorial. Please remember that scent was a PIC 16F877A but you can safely use a 16F876.

Remember that the LED will light up only if i cathodes connected to ground by means of the dip switches S13, immediately above the trimmer analog signals. The three-way dip switches are, from left, RB, RC, RD.

Before each use with a new PIC would be this deep well that is always open so as to prevent a different pinouts for such a different pic to send to ground through an LED clock.

PCB of PIC Micro-GT versatile IDE

The printed circuit board, as well as electrical diagrams in Eagle format, are available on both grix that on my personal website and freely downloadable. The cost of construction could be out of reach for many users because the PCB has many CONNECTIONS metallic loops between the solder side and component side. The factory where I commissioned sampling is in china and they have already deposited gerber files, so if and only if you are interested in a hundred can it contact Sandy that will serve as interpreter at this factory. The e-mail address is: bonzisandy88@hotmail.com

If you are interested in a single specimen or a few specimens, that would be too expensive as ordering and shipping from china factory, we can draw from my own supply, or from samples that I mentioned above. Send me a private message and I am sending to the house along with another small PCB to drive the seven segment display will use as demo board during our online course schedule.

PCB of PIC Micro-GT versatile IDE, measuring 165mm x 155mm.

. Pictured below is the second PCB in the same envelope that you receive the Micro-GT, which is indeed part of the PCB microprocessor clock that I have presented here on grix. It houses a 18-pin PIC, so it is very compact. E 'can drive 4 displays connectable via flat cable connector 12-pin sees high, With this we will do exercises in counting, views levels, numerical data (eg the floor where the elevator is located), and why not the watch itself for which the PCB was born.
 

The measures are 57mm x 45mm of PCB, dual layer technology supporting FR4.

Download the file from the link below. Hex to be included in the pic 16F84A to build with quartz clock of 3.27 MHz (accepts 4 Mhz). Sources for the modification of some parameters can be downloaded by Article clock. As a useful exercise to invite users to program a clock radio alarm clock and turn it into C16. Let's see who can present this result.

UserFiles / ad.noctis / File / orologio.hex

Conclusions

Among ten days will be released the third part of the tutorial that will tell you a preview titled "Let's go PIC!, Digital I / O" in which we will have fun with the use of inputs and digital outputs, after having obviously learned hardware the internal registers and with which these are implemented.

Users who have not yet assembled the card should hurry, as also that he wanted a come forward because as I said, I give the two PCBs for the cost of reimbursement of expenses that I incurred to build them.


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