Manual - Microtronics Pakistan
Contents
1. Friendly PIC Lab PIC Microcontroller Development Board Amer Iqbal Qureshi 4 x A 4 nu Ieg 5 s 106 1 d 4 Le w 9 ay H d User Manual Friendly PIC Lab Congratulations on purchasing our friendly PIC Lab I development board As the name suggests this is not just a trainer board but a complete development system The board 15 friendly in the sense that it does not bind your project to its configu ration like many other boards do This board is 100 configurable to user needs Powered with 18 pin PIC microcontrollers the board has a host of commonly re quired devices on it Unlike many other boards these devices are not hard wired to the I O lines of microcontroller giving you the ability to connect them to lines of your choice Each device has its connections close to pre selected I O lines on which you just place a jumper and they are connected In case you want to connect the device line to any other I O just remove the jumper and use jumper cables to connect This has made the board configurable according to your choice Just connect the de vices required for the project and to whatever I O lines you want and enjoy the pro ject Board at a Glance Have a look at board and get comfortable with position of various devices The board has a host of commonly used devices w2. LCD_RSPin PORTB O LCD_ENPin PORTB 3 Input PORTA 4 lt Se 4522 Oo Dim x As Word Dim a 12 As Word Dim i As Byte Dim c As Byte Dim d As Byte Cls Print At 1 1 Sony Remote While 1 1 wait for the signal While PORTA 4 0 Wend let header pass While PORTA 4 1 Wend GoSub gap For i 0 To 11 x While PORTA 4 1 Inc x DelayUS 1 Wend alil x GoSub gap Next i SR For i 0 To 11 2 5 l Tf ali gt 300 Then 5 hdl Else dS EndIf Next i From i2 birt data excract Lower 7 bits chac contain Che Command amp 301111111 da x gt 7
3. circuit If so then place a cable from programmer to this header and send program ming commands You will not need to take the controller out Microtronics PIC PG Programmer A number of programmers exist in market to transfer the hex file into PIC microcontrol MICROTRINICS PAK ler We have developed this simple Serial ae i ISTAN port based programmer As you can see it ro oe f has In circuit programming header just like rz gt p the one on our board Using a flat cable you 8825 s s Da just connect this header with your board and 4 now you can program your controller Decoding SONY Remote Control using PROTON BASIC compiler 22 Pal Cal Tak Gal Pal Cal Tae ale Pall cal Pam Pal Pat Pal Pa Gal Tat AAAA NAAA Uae ar Pall Pah Tal Gal Pav Past Pal Gah erat tat Pat A alt tale fat ae This program will decode Ene sony Contre without using SONYIN command The program just skips the header and gaps Yano Counts she Lvand 0 lt e 0 e sans C10 lis 54 4444 4 Ogle 4 Device 16F819 Xtal 20 All Digital true LCD_DTPin PORTB 4
4. be connected to RAO which is ANO and AN3 Reference Volts You can read about reference volts in the proper manual about analog data I would only mention that most projects do not need an external reference as they use 5V supply as reference However PIC microcontrollers allow you to get external refer ence volts RA3 or AN3 pin has this capability That is why our second Analog mod ule has by default connection to RA3 using software configuration you can set this pin as analog channel or act an ANref In that case you can connect the signal sin to 5V and set the pot to desirable levels For example your analog data is going to be in the range of 0 to 2 5V So we want the upper limit of ADC module to be 2 5V instead of 5V This will be set by AN3 as VRef and setting the output of second module to 2 5V using POT l O Line Headers Although the board contains a lot of devices that you can use to learn and explore microcontrollers but a real project will need something more than that For example you may need to have exter nal memory in the form of Ai EEPROM a real time clock or drive a set of motors You will be using some T on board like LCD and switches but want to interface with your boards This can be done by connecting your pro ject with this board through I O line headers There are two headers one for PORTA and other for PORTB Each line is labeled and each header has GND and VDD supply in case you board
5. connected in Active Low configuration with a 10k pull up resistor on active end Thus the respective I O line will see a logic 1 when switch 15 open and logic 0 when it is pushed LED Indicators LEDs are commonly used to indicate various status of the application like to indicate that monitoring of port is ON or receiving of a signal etc many development boards provide a lot of LEDs truly speaking the purpose is not an LED show but to indicate a status In any given project at the most one or two status LEDs are used However for learning purpose you may need more to refine the programming skills Each LED is connected through a 220 to 330 ohms current limiting resistor so that microcontroller pin does not get damaged The LEDs are connected through a header block to RBO RB3 RB4 and RBS Notice the placement of resistors and header block is not close to the LEDs physically The anode of LEDs is connected to the I O line and cathode 15 permanently connected to ground Thus a logic High on J O line will make the LED glow and a logic O will turn it Off Note that the default connections of LEDs to RBO RB3 RB4 and 85 are also used by LCD module Therefore if you want to use both devices in a project you will need to redirect the connections to some other pins using jumper cables Heavy DC Load using TIP 122 Some applications may require driving a somewhat heavy DC load This can be a fan DC motor a solenoid or even a rel
6. needs 5V supply from this board Note the VDD header pin is directly connected 0 the main VDD 5V supply of the board In case your exter nal board has its own supply do not connect it to VDD of this board Connecting GND 15 OK indeed required This 15 to avoid an accidental higher volts to enter this board and damage it Note PORTA headers have RA6 and RA7 as well they are usually connected to os cillator and not used as I O lines however if you have disconnected the oscillator and using internal oscillator then these lines are available as digital I O Similarly the line labeled MCLR This line can be configured as RAS if MCLR function is disabled using software settings However note this pin has a 10K pull resistor on it In Circuit Serial Programming The traditional method for programming mi crocontrollers was to insert the controller into a specific device called programmer transfer the compiled hex file into the controller and then take the controller back into the development board This method requires removal of controller from the board again and again that can damage the legs and is cumbersome The standard method today is to use In Circuit Programming We have therefore pro vided a header called CSP for that In order to use this port for programming you will need to read the guidelines from microchip about in circuit programming Your programmer must have the capability to program microchip microcontrollers in
7. SART with MAX2372 level shifter has been pro vided on board for communication with PC and other devices if required by the project The interface of the USART device is an RX and TX line indicated at a header close to the de vice The RX pin will receive data from microcontroller and send to the host device your PC for example The TX line will transmit data sent by host device to your microcontrol ler Opposite to these pins are pins with labels B2 and B1 These are the RB2 and 81 lines from microcon troller Microcontrollers with USART module in them use RB2 to send data Tx and RBI to receive data Rx Thus if jumpers are placed on these lines the Rx of PC will get connected to Tx RB2 of microcontroller and TX of PC to RX of Microcontroller When jumpers are removed the pins are free and using jumper wires you can con nect the Tx and Rx of Pc to any other lines of microcontroller and use Software commands to produce serial data communication Similarly in applications that do not need serial communication and you want to use 882 and RB1 in your applica tion removing jumpers will free the I O lines HD44780 Character LCD Character LCD is most commonly used to display the results from microcontrollers HD44780 is the industry standard LCD type that is easy to use Most of the popular compilers provide pre compiled libraries to communicate with this LCD type A header has been provided on this board to eas ily pl
8. ay We have provided a TIP 122 Darlington pair for that The TIP122 will take its DC load directly from the one provided by DC adapter Although TIP122 can easily tolerate currents up to 5A We 1 suggest to remain within to 1 5A as the power will be supplied through 1N4007 diode which may not tolerate very heavy current load The DC load is inserted into the T Block and the TIP122 can be controlled from RB3 when jumper is connected Notice RB3 is also CCP1 which means hard ware PWM module So using PWM you can increase or decrease the power de YOD12 BO R RB3 livered to DC load Note a true PWM needs a properly setup low pass filter to give analog output 38 KHz Infra Red Remote Sensor Most of the commonly used remote controls use 38KHz modu lated infra red beams to send commands This board has a stan dard sensor that can detect only 38KHz modulated signals and will ignore all other type of IR signals The sensor by itself gives a logic low signal when the IR signals are received and high when there is no signal This is OK for re mote control applications and indeed some compilers like PRO TON Basic have built in command to decode the Sony remote controls However if you want to use it to communicate serial data using an IR LED then this becomes a problem as serial modules when send logic high they expect the logic high on other end We have rectified this problem by using a transisto
9. ith microcontroller projects Power Supply The board has to be given external power supply through a sta ble DC outlet It has its own 5V regulator therefore the supplied power can be anything from 6V to 12V We prefer a 9V supply The 5V regulator tends to get hot when given more than 12V to dissipate energy therefore it must be properly heat sinked The center of power supply pin should be positive the board has a protection diode to avoid reversed polarity feed to the cir cuit An On OFF switch has been pro vided to turn the power ON An LED close to power jack will show the power status Microcontroller Socket This board supports all 18 pin Microchip PIC mi crocontrollers Most of the Microchip PIC micro controllers are pin compatible however there can be an odd one with different layout The microcontroller does not need to be taken out of the board in most cases as it can be programmed right in the circuit In case you need to take it out and replace with another number if your project re VDO12 2 12 o 9 RAD ei RAQVAND gt RED RAI lt RATAN L gt REI RAZ ei RADIANDVREF gt REZ RAS lt RAWANSVREFs gt RBS At lt RAAANA TOCKI mmm Ellen MCLR ei RASMCLAIVPP gt REE RAG lt RABOSCAICLEO gt REG RAT lt q RATIOSC CLK gt RET HI DPI quires a different one then make sure it is inserted in correct direction We tend t
10. mple if you want to work with a 12V signal you will need to scale it down 3 times to make it 4V and then feed into the controller We have pro vided two variable resistors actually a variable voltage divider The input signal first gets into the variable resistor and from the center tape gets into PIC ADC lines Thus positioning the POT you can scale down the signal volts The Input header has pin for analog sig nal as well as 5V and GND pins This will facilitate connecting the sensors or devices that need 5V supply as well oth erwise use only signal and GND to ac quire data If a jumper is placed on signal and VDD line the POT will get 5V analog signal and you can experiment with ADC by rotating the POT to simulate various levels of O SV analog signals You can also use this arrangement to set the scale down position For example you want to work with 12V signal and want to scale it down 4 times Thus making 12V to 3V data To adjust the pot position to achieve this just place a jumper between sig nal and VDD and measure the volts using a voltmeter at center pin or output pin of the module You have to get 4 times reduced 5V thus 5 4 1 25 adjust the pot in such a way to get 1 25V at output Now remove the jumper and you can safely give 12V signal at input the output will be reduced by 4 times that will be compensated for in software by multiplying the value measured by 4 There are two such modules and by default they can
11. o supply the board with PIC16F819 microcontroller as it has built in ana log to digital converters as well that helps in acquiring external analog data Crystal Oscillator An oscillator is the heart of any microcontroller application Most microcontrollers run with an external crystal oscillator or another source Some microcontrollers now have built in oscillators as well Using those oscillators will reduce the circuit and allow you to use the pins dedicated for crystal connections as I O lines Since this is a development board it allows you to ex periment your project in any possible combination you like Notice there are two jumpers close to the crystal oscillator Placing these jumpers will connect the oscillator to the OSC1 and OSC2 lines of the chip If you take these jumpers off the oscillator 1s discon nected and now you will have to enable the internal oscillator using software commands A Quick look at the datasheet will reveal that in case of 16F819 these two lines are then available as RA6 and RA7 as general purpose digital I O lines Note these are available on I O headers of the board Do not use these lines on header if crystal oscillator is plugged in as these lines will have crystal signals then USART Serial Port Although serial port is vanishing rap idly from PCs yet it is an important device in the microcontroller world A large number of devices communi cate between themselves using UASRT protocols A U
12. r inverter on the IR sensor output Thus our board will give a logic high when 38KHz modulated signals are received and logic 0 when not If you combine it with a simple IR LED that can be easily plugged into I O lines you can easily make IR modem This arrangement however failed the SONY remote command with PROTON Basic as it assumes a logic low when there is signal We have provided a complete program to decode the Sony IR remotes at the end of this manual using this non inverted arrangement The output of IR sensor can be connected to RA4 through jumper located on the LCD jumpers block Using jumper wires you can relocate the sensor output to any other line of choice Analog Inputs PIC microcontrollers vary in built in Analog to digital converter modules Some controllers like 16F84 do not have ADC in them while 16F628 has only comparator modules 16F819 has 5 channels of analog data Details of these channels and the pins are given in datasheets of the concerned controller Acquiring analog data can be a daunting task First of all stray signals and sampling line capacitance tend to change the data shape Secondly analog data can be low voltages or high PIC ADC can handle voltages only up to 5V Therefore smaller volts are not a problem but a signal more than 5V can be problem The standard practice 15 to protect the I O lines with a 5 1V zener diode and secondly to use a voltage divider to scale down the incoming signals For exa
13. ug in LCD when required Also a jumper LCD header with LCD connections on one side and recommended microcontroller connections on other side has been provided Placing the jumpers will connect the LCD to these 1 lines In case your project requires these lines and you want to relocate the LCD connec tions just unplug the jumper or jumpers and use jumper wires to connect the LCD lines to I O lines of your choice Most designs of LCD require a potentiometer to set the contrast we have permanently pro vided contrast through a 1 5K resistor You therefore can not set contrast of LCD in this board The value is optimum if your power is 5V with sufficient amperes to give the best contrast The backlight of LCD has been given power directly so in this board back light can not be controlled Note the same header block is also used to connect IR sensor which has no direct connection with LCD Push Switches Push switches or momentary switches as they are generally called are also commonly used to get user response or to simulate in a prototype the input from an on off type sensor Essentially you can call push switch a simple touch sensor There are three switches on board and their connections are again provided through jumpers to RB7 RA2 and RAI just like any other device if you want to relocate the connections unplug the jumpers and using jumper wires connect to lines of your choice These switches are
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