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By JOHN CLARKE Open doors with this Fingerprint Access Controller Uses a fingerprint scanner & an electric door strike Do you hate carrying keys? So do we! Would you like to open your front door, security gate or your garage door with your finger? Now you can! This project comprises a fingerprint scanner (FPS), a 2-row LCD and an electric door strike, all controlled by a PIC16F88 microcontroller. S OME LAPTOP PCs and smartphones have a fingerprint scanner to enable to you access them and now you can build a project which works along similar lines. It can store and recognise up to 20 fingerprints and can give access to your home or workplace at any time, day or night. There’s no need to fiddle around with keys – all you need is a finger! The fingerprint scanner (FPS) we have used is the GT-511C1R, manufactured by ADH-Tech in Taiwan and available from SparkFun Electronics in the USA and Little Bird Electronics in Australia. It isn’t cheap at around 26  Silicon Chip $56 including GST but getting copies of door keys for up to 20 people can cost a similar amount. The GT-511C1R FPS comprises an optical sensor (specifically a CCD camera) with an opaque screen (14 x 12.5mm) which you cover with your finger, to scan it. The camera records the fingerprint image which is compared with those stored in a database. If your print is in the database, the micro will unlatch the door, via the electric door strike. As can be imagined, there is a lot of processing required to compare one fingerprint with a database and the GT- 511C1R uses an ARM Cortex-M3 32-bit processor that’s specifically designed for real-time data processing; ideal for processing the 240 x 216 pixel image of a fingerprint. It breaks the photographed image down into a 504 byte template that becomes a digital representation of the fingerprint. All the fingerprint image capture, digital template data and fingerprint identification is done within the FPS but to make it work, it must be used in conjunction with a computer or microcontroller. Connection to the FPS is made via a JST-SH 4-way wired header plug which provides the DC siliconchip.com.au Main Features •  Identifies up to 20 separate fingerprints •  LCD module guides operation •  Drives an electric door strike (latch) to open a door •  Enrolments & deletions easily accomplished •  Errors shown on LCD •  Adjustable door strike activation period   Adjustable scan resolution •   Additional security features • power and serial lines to carry the commands and the data. These commands are for switching on internal LEDs for backlighting the FPS screen and for enrolling or validating a fingerprint against those stored in the database. The computer or microcontroller does not need to be high-powered; a simple 8-bit microcontroller will suffice. The data-sheet for the FPS is available at www.sparkfun.com/products/ 13007 There is an evaluation executable file that can be run on a computer using a serial port (or USB to serial converter) to connect to the FPS. The demonstration file is available at https://cdn.sparkfun.com/datasheets/Sensors/Biometric/GT-511C1R_ SDK_20140312.zip While the demonstration file shows what the FPS can do, it is not suitable for a practical fingerprint security access system that can release the door strike of a door lock. For that we need a more dedicated circuit and custom software. Our system combines the GT-511CR FPS with a 2-line LCD module. This module is used when enrolling fingerprints and when selecting the various options using four pushbutton switches. These components, along with a PCB containing the PIC16F88 microcontroller, are mounted in a bulkhead case measuring 120 x 70 x 30mm. The whole works is powered using a 12V 1A DC plugpack and this provides the brief power pulses for the electric door strike as well. Features & operation Normally, the FPS would be mounted on a wall-plate just outside the locked door while the control box is siliconchip.com.au mounted on the other side of the door. The electric door strike is a door latch and when it is powered, the latch becomes free so that the door can be pushed open. In normal operation, the FPS flashes its blue back-lighting LEDs once a second and each time checks whether a finger is pressed on the screen. If so, the LEDs stay lit and the fingerprint is compared with those in the database. The door-strike will then be briefly pulsed to open the door, if the fingerprint is valid. If the fingerprint is not matched in the database or there are no current enrolments or there is a fingerprint reading error, the LEDs will flash rapidly at four times a second, for 2.5 seconds. At the same time, the error will be displayed on the LCD screen. Other errors are related to security breaches as discussed later. These will cause the FPS blue LED back-lighting to stay off until the fault is acknowledged, using the Enter button on the control panel. To make it work, you need to enrol one or more fingerprints so there is a database. Enrolment and other functions are done using the four pushbutton switches on the control panel. The four buttons are, from left to right: Menu, Enter, Down and Up. Once powered up, the default homescreen on the LCD shows Fingerprint Security Access. Repeatedly pressing the Menu button lets you cycle through five menus, the first of which is for enrolling a new identity (ID). The ID numbers can be scrolled up or down using the buttons and only the unused ID numbers will be shown. Pressing the Enter button then starts the enrolment procedure, during which you will be instructed to place your finger on the FPS. The next menu is for deleting an enrolled ID. Only enrolled IDs will be shown, by scrolling up or down. Pressing the Enter button deletes the selected ID. The third Menu deletes all enrolled IDs; useful if you want to clear everything and start again. It is much faster than deleting enrolments one by one. The fourth and fifth menus let you adjust the scan resolution and the door-strike energising period. The door-strike operating period is adjustable from 1s up to 255s. The Up and Down buttons are used to make the changes. The FPS (fingerprint scanner) can be mounted on a blank wall-plate adjacent to the locked door, while the control box is mounted inside the room. Shown here slightly larger than actual size, the GT-511C1R FPS can enrol up to 20 fingerprints. The module measures just 37 x 17 x 9.5mm (L x W x D). The scan resolution essentially sets the resolution of the captured fingerprint during access. It does not change the enrolment resolution of the fingerprints; that’s always at the highest resolution. A low resolution selection makes the database search faster compared to using the high resolution selection. The next press of the Menu button takes the system back to the home screen. Alternatively, the system will automatically return to the homescreen after 25 seconds if a menu item is selected and no further buttons are pressed. Note that the LCD module lights up when any switch is pressed. It also November 2015  27 FINGERPRINT SCAN MODULE OUT K IN A – 100 µF GND 10 µF 12 34 16V CON1 100nF 10 µF 6 14 RA5/MCLR Vdd 2 RA6 RB0 RA7 10 RB4 S4 9 ^ UP RB3 TO FPS MODULE Tx Rx GND +5V SERIAL No. LOAD 13 8 560Ω 2 3 4 11 16 6 RA3 RB6 RB5(Tx) 15 RS LCD MODULE EN RA4 8 GND 7 BACKLIGHT – 1 16 18 1 17 C 1k 2 Q1 BC337 B 12 Q2 IRF540 10Ω G S Vss 5 1N4004 K FINGERPRINT ACCESS CONTROLLER B E G C 7805 IRF540 BC 33 7 SC D E 3 A 20 1 5 CONTRAST VR1 10k 3 CONTRAST R/W 14 13 12 11 10 9 RA2 RB2(Rx) CON2 BACKLIGHT + Vdd D7 D6 D5 D4 D3 D2 D1 D0 RA1 RB7 1k 4 5 RA0 1 15 IC1 PIC1 6F88 6F8 8– – I/P S5 A +5V RB1 S3 DOWN ^ D2 1N4004 0.5W S2 ENTER 10 µF 390Ω 4 7 MENU TO DOOR STRIKE K 1k S1 DC INPUT 12V/1A + D1 1N4004 REG1 7805 +5V D D GND IN S GND OUT Fig.1: the circuit is based on a GT-511C1R FPS, PIC microcontroller IC1 and a 2-line 16-character LCD module. IC1 sends and receives data to and from the FPS module via its serial port (pins 8 & 11), monitors pushbutton switches S1-S5 and drives the LCD. It also drives Mosfet Q2 to activate the electric door strike when a valid fingerprint is scanned by the FPS. Transistor Q1 is driven by IC1’s RB6 output and controls the LCD’s backlight. lights when the LCD screen changes to indicate the type of access (whether allowed, denied or security errors). The backlight automatically turns off after 10 seconds, except for security breach errors in which case the backlight will stay on. Foiling security breaches Since the FPS is likely to be located in an unsecured area, there is a risk of attempted security breaches. However, we have incorporated some features to make unauthorised tampering ineffective. First, if the FPS is swapped with another one, access will be denied because each FPS has its own unique serial number. Second, if the original FPS is temporarily disconnected and connected to another Fingerprint Security Access controller to set up a new enrolment (eg, with the intruder’s fingerprint), this too will be foiled. Access will be denied even though the correct FPS is 28  Silicon Chip reconnected with the matching serial number. When the FPS is reconnected and a finger is subsequently detected on the screen, the Fingerprint Access Controller will detect that the enrolments have changed. A tamper message will then be displayed on the LCD screen and all access will be denied. Two other security measures are also incorporated to counteract any “hot wiring” exchanges of the FPS. If the FPS is disconnected and reconnected while power is applied, the Fingerprint Access Controller will immediately halt operation, preventing any access. Similarly, if the FPS is quickly hotswapped from one control unit to another using a switched lead, operation will halt. During this halt, the FPS will have its blue back-lighting off to indicate a fault. No indication will be issued on the LCD screen and the switches will not have any effect. The Fingerprint Access Controller will then need to be powered down and powered up again to restore operation. Circuit description Fig.1 shows the circuit for the Fingerprint Access Controller. It comprises the fingerprint scanner (FPS), a microcontroller (IC1) and a 2-line 16-character LCD module. Each of these is complex in itself but they make the rest of the circuit quite simple. The LCD is driven by IC1 via its four most-significant data lines (D4-D7), while lines D0-D3 are tied to ground. When driving the LCD, data is sent in two 4-bit portions to make up the full 8-bit data. Driving the display in this way saves having to dedicate an extra four connections to IC1. The EN (Enable) and RS (register select) lines are driven via IC1’s RA7 and RA6 ports to control the clocking and data flow to the LCD. The LCD module’s contrast control is trimpot VR1 which is adjusted to siliconchip.com.au Specifications Finger Print Scanner (FPS) Scope 1: the top trace of this scope grab shows the commands sent to the FPS during a scanning routine. First, the FPS backlight is switched on, then a check is made to detect if a finger is placed on the FPS screen. In this case, there is no finger present and so the backlighting is switched off. The lower trace shows the acknowledgement from the FPS. give the best screen contrast. Transistor Q1 controls the LCD module’s backlighting and its base is driven with a PWM signal from IC1’s RB6 output. The backlight LEDs are supplied via a 390Ω 0.5W resistor connected to the 12V supply (following diode D1). The FPS module is driven by IC1’s serial port. As shown, IC1’s receive input (Rx) at pin 8 connects to the transmit (Tx) pin of the FPS module. Similarly, IC1’s transmit (Tx) pin (pin 11) connects to the receive (Rx) pin of the FPS. A resistive divider reduces the 5V transmit signal from IC1 down to a nominal 0-3.3V to make it suitable for the FPS’s Rx input. The FPS uses an 8-bit data and one stop bit format and the default baud rate is 9600 baud. However, faster rates such as 19,200, 38,400, 57,600 and 115,200 baud can be selected by sending a command and baud rate parameter and IC1 actually does this, depending on its mode. Data sent to the FPS begins with four header bytes (55, AA, 01, 00) for the start bits and device ID, then a 4-byte parameter value followed by a 2-byte command value and 2-byte checksum. Acknowledgement from the FPS follows a similar format. When reading the serial number, an extra 30 bytes of data is sent. This incorporates the 16-byte serial number, with the remainder being start bytes (this time it’s 5A and A5), device ID, firmware version, size of captured image, serial number and a 2-byte checksum at the end. All data is sent and received with the least significant bytes first (“Little Endian”, as the data sheet describes it). siliconchip.com.au CPU: ARM Cortex-M3 core (32-bit) Sensor area: 14 x 12.5mm Image size: 240 x 216 pixels Resolution: 420dpi Maximum number of fingerprints stored: 20 Template size: 504 bytes Communication: 9600 baud (default) to 115,200 baud, (eg, 19,200, 38,400, 57,600) False acceptance rate: <0.001% False rejection rate: < 0.1% Identification time: minimum of 1.5s but usually longer depending on number of fingerprints stored Operating Voltage: 3.3-6V Current: 130mA with sensor LEDs on Operating temperature range: -20°C to +60°C Control Unit Power supply: 12V DC <at> 1A FPS connection: JST-SH 4-way wired header plug lead (tested up to 1.2m long) Current consumption: scanning, 150mA; FPS blue LEDs on, 200mA; doorstrike on 700mA LCD backlight: turns on when a switch is pressed and during fingerprint detection; automatically turns off after ~25s Fingerprint scanning: detect once per second with FPS LED flashing at 1Hz Home screen: appears during scanning; automatically returns after 25s if no switches are pressed during this time Door strike activation period: adjustable from 1-255s Fingerprint scan resolution: selectable low or high Enrolment control: add a new enrolment ID, delete an enrolment ID and delete all enrolments Additional security: FPS unique serial number check; check for correct number of enrolments plus two more undisclosed security techniques The accompanying scope grabs illustrate the circuit operation. Scope1 shows the normal scanning routine where the FPS backlight is switched on, then a check is made to detect if a finger is placed on the FPS screen. In this case, no finger is present and so the backlighting is switched off. The data sent to the FPS is the top trace and is shown in the above order, ie, backlight on, check for a pressed finger, then backlighting off. The acknowledgement from the FPS is shown in the lower trace and occurs immediately after the serial data is sent for backlighting on and off, but with a delay of around 125ms for the response while the FPS checks if a finger is present. The received serial data response length is about 7.5ms long in each case. Scope2 shows the data sent to re- trieve the serial number of the FPS. Note how much more data is returned, taking some 26.5ms compared to the normal response of around 7.5ms. Scope3 shows the complete code sent to switch the FPS backlight off, expanded out to 1ms per division. Pushbuttons IC1 also monitors pushbutton switch­es S1-S5 which are connected to inputs with internal pull-ups. These hold each input high (5V) unless a switch is pressed, which pulls the respective input low (0V). The electric door strike solenoid is driven via Mosfet Q2 and its gate is driven by IC1’s RA4 output via a 10Ω resistor. One side of the door-strike is connected to 0V when the Mosfet is switched on. The other terminal of the door-strike connects to the 12V rail November 2015  29 15190130 ALTRONICS YTIRU CES T NIRPRE G NIF Z-7013 (B/L) 16X2 LCD MODULE VR1 10k S5 1k 1k 10 µF 100 µF 1 3 4 2 1 1 2 3 4 TO FPS SCANNER D1 CON1 4004 10Ω 4004 D2 PIC16F88 390Ω 1k IC1 10 µF 10 µF Q2 IRF540 BC337 * 100nF CON2 TO DOOR STRIKE REG1 7805 14 13 12 11 10 9 8 7 6 5 4 3 2 1 16 15 560Ω 03109151 C 2015 rev.1 Q1 FINGERPRINT SECURITY 03109152 S1 03109152 FOUR PIN SIL HEADER MOUNTED ON UNDERSIDE OF THIS PCB rev.0 THREE PIN SIL HEADER MOUNTED ON UNDERSIDE OF THIS PCB FINGERPRINT SECURITY SWITCHES S2 S3 S4 * NOTE: 16-WAY SIL SOCKET ON MAIN PCB, 16-WAY SIL HEADER ON UNDERSIDE OF LCD MODULE Fig.2: follow this parts layout diagram to build the two PCBs. Use a socket for microcontroller IC1 and make sure that all polarised parts (including switches S1-S4) are correctly orientated. The photo below shows the completed PCB assemblies, together with the LCD module. via reverse polarity protection diode D1. Diode D2 quenches the back-EMF pulse produced by the door-strike solenoid when it is switched off. Garage door opener The FPS does not have to be used 30  Silicon Chip with an electric door strike. For example, it could instead be used with a garage door opener which is triggered by shorting two contacts; shorting the contacts operates the door, either to open or close it. In that case, the source and drain of the Mosfet need to be brought out to a 2-pin connector and then connected via a figure-8 cable to the switch contacts on the garage door opener. Alternatively, a 12V relay could be wired to CON2 in place of the door strike to do the switching operation. The supply for IC1, the LCD and the FPS is derived via REG1, a 5V 3-terminal regulator. A 100nF capacitor decouples the supply to IC1 close to its supply pins, while the supply for the LCD module is decoupled using a 10µF capacitor. Power is applied from a 12V DC plugpack to REG1 via reverse polarity protection diode D1. A 100µF capacitor decouples the supply to REG1 while its output includes a 10µF supply bypass capacitor. Construction All the parts for the Fingerprint Access Controller are installed on two PCBs: (1) a main board coded 03109151 (114 x 53.5mm) which accommodates most of the parts, including the LCD module; and (2) a switch board coded 03108152 (62 x 14mm) which accommodates the four pushbutton switches (plus two pin headers) and which plugs into the main PCB. The completed assembly is housed in a 120 x 70 x 30mm bulkhead style case with a transparent lid. Fig.2 shows the parts layout on the two PCBs. The main board can be assembled first. Begin by fitting the resistors, taking care to install each one in its correct location. Table 1 shows the resistor colour codes but you should also use a digital multimeter to check each resistor before soldering it to the PCB. Diodes D1 & D2 go in next (take care with their orientation), followed by an 18-pin DIL socket for IC1. The 4-way and 3-way SIL (single in-line) sockets, used to later mount the switch PCB, can then be installed. These socket strips are obtained by cutting down a DIL IC socket using a sharp knife or side-cutters. It’s a good idea to smooth the cut edges with a file before installing the socket strips on the PCB. Similarly, the LCD module is mounted via a 16-pin SIL socket strip and this can also now be installed. The capacitors are next on the list. Note that the electrolytic types must be orientated as shown. Follow with REG1 and Mosfet Q2. These devices are mounted with their siliconchip.com.au Parts List Scope 2: this scope grab shows the data sent to retrieve the serial number of the FPS. Note how much data is returned, taking some 26.5ms compared to the normal response of around 7.5ms. Scope 3: the complete code sent to switch the FPS’s back-light off is shown here, expanded out to 1ms per division. metal tabs flat against the PCB (ie, their leads must be bent down through 90° to pass through their respective holes). Secure each device to the PCB using an M3 x 6mm screw before soldering its leads. Don’t solder the device leads first; if you do, the PCB tracks could crack as the tab screws are tightened down. Be careful not to get Q2 & REG1 mixed up – they look much the same. Transistor Q1 (BC337), trimpot VR1, the DC socket (CON1), the 2-way screw terminal block (CON2) and pushbutton switch S5 can then go in. Check that CON1 & CON2 sit flush against the PCB before soldering their terminals. Switch PCB Attention can now be turned to the Semiconductors 1 PIC16F88-I/P microcontroller programmed with 0310915A. hex (IC1) 1 7805 5V 3-terminal regulator (REG1) 2 1N4004 1A diodes (D1,D2) 1 BC337 NPN transistor (Q1) 1 IRF540 N-channel Mosfet (Q2) 1 double-sided PCB, code 03109151, 114 x 53.5mm 1 double-sided PCB, code 03109152, 62 x 14mm 1 GT-511C1R fingerprint scanner (Littlebird Electronics SF-SEN13007) 1 JST-SH 4-way wired header plug, 200mm lead length (Littlebird Electronics PRT10359) 1 12VDC 1A plugpack 1 bulkhead case, 120 x 70 x 30mm (Jaycar HB-6082) 1 blank wall-plate (to mount fingerprint scanner) 1 12V electric door strike (failsecure) (Jaycar LA-5077, Altronics S 5385, S 5387A) 1 16 x 2 LCD module with backlighting (Jaycar QP-5512, Altronics Z 7013) 4 click-action pushbutton switches, PCB-mount, white (Jaycar SP0723, Altronics S 1099) (S1-S4) 1 SPST PCB-mount tactile switch (Jaycar SP-0600, Altronics S 1120) (S5) 1 18-pin IC socket 1 40-pin IC socket cut into 16-way, 4-way & 3-way SIL header strips 1 23-way SIL header strip cut to 16, 4 & 3-way lengths 1 PCB-mount DC socket (Jaycar PS-0520, Altronics P 0620, P0621A) (CON1) 1 2-way screw terminal block, 5.08mm pin spacing (CON2) 2 M3 x 6.3mm tapped spacers 6 M3 x 6mm screws 2 M3 nuts 4 No.4 self-tapping screws switch PCB. The 3-way and 4-way pin headers go in first. These are installed on the underside of the board and must be fitted with their shorter pin lengths going into the PCB holes. The header pins are then soldered on Capacitors 1 100µF 16V PC electrolytic 3 10µF 16V PC electrolytic 1 100nF MKT polyester Resistors (0.25W, 1%) 3 1kΩ 1 560Ω 1 390Ω 0.5W 1 10Ω 1 10kΩ miniature trimpot, horizontal mount (VR1) (code 103) Miscellaneous 1 1m length of 4-way rainbow or telephone cable (length to suit installation) 1 short length of 2mm-diameter heatshrink tubing 1 length of figure-8 wire to connect door strike 1 12V bezel indicator lamp (LED or filament type) (optional to show door-strike operation) Where to buy a kit A complete kit of parts for the Fingerprint Access Controller will be available from Altronics for $99.95, Cat. K 9350. This kit will include the GT-511C1R module and a punched wall plate but not the door strike. the top (switch side) of the PCB. Once the headers are in place, the four pushbutton switches (S1-S4) can then be fitted. Install them with the flat side of each switch orientated as shown and make sure that they sit Table 1: Resistor Colour Codes   o o o o o siliconchip.com.au No.   3   1   1   1 Value 1kΩ 560Ω 390Ω 10Ω 4-Band Code (1%) brown black red brown green blue brown brown orange white brown brown brown black black brown 5-Band Code (1%) brown black black brown brown green blue black black brown orange white black black brown brown black black gold brown November 2015  31 reading, switch off and install IC1. The two M3 x 6.3mm standoff mounts for the LCD module can now be secured to the main PCB using M3 x 6mm screws. That done, plug the LCD into its header socket and secure it to the standoffs at either end using another two M3 x 6mm screws. Preparing the case This view shows the completed PCB assembly, with the LCD module and the switch board installed. Note that the cable that runs to the FPS is soldered to the main PCB before the switch board is fitted (see text). flush against the PCB before soldering their pins. The assembled switch PCB can then be plugged into the main PCB but note that there is a right way and wrong way to install it – the 4-way pin header must be plugged into the 4-way socket, while the 3-way header goes into the 3-way socket. Once the header is in place, cut a short strip of thick cardboard exactly 7mm wide. This cardboard strip is then used as a gauge while the header pins are trimmed using side-cutters – ie, the header pins are trimmed so that their ends are 7mm below the underside of the LCD module’s PCB. Installing the LCD Before applying power for the first time, make sure that microcontroller IC1 is out of its socket and that the LCD is unplugged. Check the assembly carefully, then apply power and check that there is 5V between pins 14 & 5 of IC1’s socket. If there’s no reading, check REG1 and the orientation of diode D1. Assuming you do get the correct Before installing the LCD, a 16-way SIL pin header must first be fitted to its bottom edge. This is installed from the underside of the PCB with the short pin lengths going through the holes. Check that the header is seated correctly before soldering its pins on the top of the board. Applying power The completed PCB assemblies can now be placed to one side while you prepare the case. The first step is to drill a 10mm-diameter hole for the DC socket. Fig.3 shows the drilling template and this can either be copied or downloaded in PDF format from the SILICON CHIP website (www.siliconchip.com.au) and printed out. Use a small pilot drill to start the hole, then carefully enlarge it to size using larger drills and a taper­ ed reamer. Fig.4 shows the front-panel artwork (also available from our website). This can be used as a drilling template for the four front-panel switches. The holes should all be drilled and enlarged with a tapered reamer to a dia­ meter of 10mm. Finally, you will have to drill two holes in the base of the case – one to feed through the wiring from GT511C1R fingerprint scanner (FPS) and another to accept the wiring that runs from the electric door-strike to CON2. Note that the wiring to CON2 is fed through the PCB via a hole immediately in front of this terminal block. The positions of the two holes in the base are not particularly critical. The hole for the FPS wiring can be drilled so that it will be roughly in-line with the FPS pads on the PCB. The doorstrike wiring hole can be positioned in-line with this first hole, so that it will sit more or less behind Q2. Note that the wiring connector for the FPS is fitted with a JST-SH plug (see parts list). This means that the FPS wiring hole will need to be large enough for the JST-SH plug to pass through. Extending the leads The completed PCB assembly is secured inside the case using four self-tapping screws that go into integral stand-offs. The case comes with a transparent lid so there’s no need to make a cut-out for the display, although it is necessary to drill holes for pushbutton switches S1-S4. 32  Silicon Chip As supplied, the lead fitted to the JST-SH plug is just 200mm long. It will therefore probably be necessary to extend this lead, depending on the relative positions of the FPS and the control box. We tested the unit with a lead length of 1.2m without any problems. To extend the cable, you can solsiliconchip.com.au   Dataflex/Datapol Labels (1) For Dataflex labels, go to: www.blanklabels.com.au/index. php?main_page=product_info& cPath=49_60&products_id=335 (2) For Datapol labels go to: www. blanklabels.com.au/index.php? main_page=product_info&cPath =49_55&products_id=326 must be connected in the correct order to pins 2, 3 & 4 on the main PCB. Double-check this if using an extension cable, to ensure that the connections are still correct. This label can then be attached to the inside of the lid using clear silicone sealant and the holes for the switches cut out with a sharp hobby knife (note: you will be able to see some of the “workings” inside the case with this panel). Alternatively, you can print onto a synthetic Dataflex or Datapol sticky label (see panel) and attach that to the lid after cutting out the LCD hole. The switch holes can then be cut out. Place the lid to one side after affixing the labels. It’s attached to the case later, after the test and adjustment procedure has been completed. Final assembly Mounting the FPS Now for the final assembly. It’s basically a matter of feeding the JST-SH plug and its lead through the corresponding case hole, then sitting the PCB in position inside the case so that it rests on the four integral standoffs at the corners. The PCB is then secured to these standoffs using No.4 self-tapping screws. The next step is to produce and fit a front-panel label to the case lid. There are a couple of options here, the first being to print the downloaded PDF file onto clear overhead projector film (use film that’s suitable for your printer). In most cases, you will want to mount the FPS module on a standard blank wall switch-plate (see photos). You will need to cut a 16 x 20mm hole to accept the scanning lens and this should be carefully filed to size so that the module is a tight fit. Once it’s in position, the FPS module can be secured in place using silicone sealant. If the FPS isn’t going to be wallmounted, then it can be mounted in a zippy box. The GT-511C1R FPS is mounted on the rear of a blank wall-plate. You will need to cut a 16 x 20mm hole to accept the scanning lens. Once it’s in place, the module can be secured to the rear of the wall-plate using silicone. der a 4-way rainbow cable or 4-way telephone cable to the FPS pads on the main PCB. The individual wires are simply pushed through the holes from the underside of the PCB and soldered on top side (ie, to the left of D1). The extension cable can then be connected to the JST-SH lead by first sliding short lengths of 2mm-diameter heatshrink tubing over the wires, then soldering the individual leads together. The heatshrink tubing is then slid over the solder joints and shrunk down with a hot-air gun. Finally, the joins can be secured by sliding a length of 5mm-diameter heatshrink over the whole lot and shrinking it down. Make sure that the JST-SH cabling is connected with the correct polarity. The black lead on the JST-SH plug is pin 1. The remaining white wires Testing Now for the test procedure. First, SIDE PANEL DRILLING TEMPLATE + 10MM-DIA HOLE FOR DC SOCKET SILICON CHIP www.siliconchip.com.au MOUNTING FLANGE + < + + + 12V DC <at>1A . siliconchip.com.au Menu < Fig.4 (right): the full-size front-panel artwork. It can be copied or downloaded as a PDF file from the SILICON CHIP website and used as a drilling template for the switches. The PDF file can also be used to print a sticky label – see box panel. Fingerprint Access Controller + Fig.3 (above): the drilling template for the righthand end panel of the case. A 10mm hole is required to provide access to the DC socket on the PCB. November 2015  33 Dealing With Security Errors If the display shows Serial No. Error, this means that the FPS has been changed, either by a prospective intruder hoping to defeat the system or by someone authorised to replace the unit. In the latter case, the security number of the FPS will need to be reloaded in order to get the Fingerprint Access Controller working again. That’s done by pressing and holding down switch S5 inside the control unit. This will load the new FPS security number and the switch can be released when the LCD screen shows Loading FPS Serial No. Alternatively, if the FPS has been replaced by an unauthorised person, then it would be wise to delete all enrolments after reloading the FPS serial number and start again. An Enrolment Tamper indication on the display indicates that an enrolment has been made to the FPS using a different controller. Once again, it would be wise to delete all enrolments and start again. Table 2 summarises the security errors. If the FPS back-lighting doesn’t flash and the switches have no effect, the unit has probably halted due to some form of FPS tampering, as detailed in the main article. In that case, the control unit should first be powered down and then powered up again. It’s then just a matter of checking if the unit is operating again and that access is possible when a valid fingerprint is scanned. Table 2: Security Errors Security Error On LCD What It Means Serial No. Error Press Enter (Enter returns to the home screen, FPS blue LEDs are off) The serial number of the connected FPS doesn’t match the serial number stored in the control unit. If the FPS swap is legitimate, press S5 in the control unit to read and store the new serial number. If not, delete all enrolments in the new FPS and press S5, then re-enrol valid fingerprints. Enrolment Tamper Press Enter (Enter returns to the home screen, FPS blue LEDs are off) One or more enrolments have been made to the FPS using a different controller. Delete all enrolments and start again. check that the FPS module is unplugged, then apply power and adjust trimpot VR1 for optimum contrast on the LCD. That done, switch off, connect the FPS module and apply power again. When the complete unit is powered up, it will automatically read and store the FPS module’s unique serial number in the PIC microcontroller IC1’s EEPROM (non-volatile memory). At the same time, the LCD module will display Loading FPS Serial No. for a short period before showing the normal home screen which displays Fingerprint Security Access. Once the serial number has been loaded, the FPS should briefly flash its blue back-lighting LEDs once every second. If you then place a finger on the FPS sensor, the blue back-lighting LEDs should light continuously, indicating that a finger has been detected. At this stage, no fingerprints will be stored in the database and so you 34  Silicon Chip will be greeted by an Access Denied No Enrolments message. The next step is to check the switch functions on the switch PCB. As mentioned previously, these four switches (designated Menu, Return, Down and Up) allow for enrolments and other changes. Each time the Menu button is press­ ed, the display should cycle between the NewEnrol ID, Enrolled ID, Delete All IDs, Scan Resolution and Door Strike Time menus. Check that this switch functions correctly, then check the operation of the Enter, Down and Up switches. Note that these latter three switches are only effective when menus are opened. Once you have confirmed that everything is working correctly, fasten the lid in place using the four self-tapping screws supplied with the case. Entering enrolments This unit is simple to set up and use. The first step is to enrol fingerprints into the FPS unit and that’s done as follows: •  Press the Menu button to bring up NewEnrol ID menu – see Fig.5. The controller then checks the enrolments list and the first lowest ID number available will be shown. If the database is full, the LCD will display an Enrolments Full message. In that case, you would first need to delete an enrolled ID. •  Press the Up and Down buttons if you wish to select a different enrolment number to that shown. Note that any previously enrolled ID numbers will not be displayed. •  Press the Enter button to start the Enrolment process for the displayed ID. This involves taking three separate fingerprint scans which are then merged into the scanner’s database. During this process, you are first prompted to place your finger on the scanner (Press Finger) so that the first fingerprint “capture” can be made. You are then asked to remove the finger (Remove Finger) before being instructed to press the finger on the scanner again. This is then repeated once more, after which Enrolled will be displayed on the LCD to acknowledge the enrolment. Note that the Enrolled message is only displayed for about one second, after which the unit returns to the Fingerprint Security Access message. •  Any errors during enrolment are shown on the LCD as Enrolment Fail, Poor Fingerprint or Finger Off Error. If that happens, the unit returns to the start of the enrolment and the process must be started all over again. It’s not unusual to have to make more than one attempt to achieve a successful enrolment. Note that a dry finger is not always readily recognised and it may be necessary to slightly moisten your finger before placing it on the scanner. In addition, try to place your finger in a similar position on the scanner each time during the enrolment process. Deleting enrolments Deleting enrolments is straightforward. All you have to do is press the Menu button to bring up the Enrolled ID menu or the Delete All IDs menu and press the Enter button. If the Enrolled ID menu is selected, only the displayed enrolment ID will be deleted when the Enter button is pressed siliconchip.com.au When the home screen is shown, the FPS backlight flashes at a 1Hz rate and the unit is ready to scan fingerprints for access control. Scan Fingerprint HOME SCREEN Match Found FIRST MENU BUTTON PRESS SECOND MENU BUTTON PRESS The first press of the Menu button allows new enrolments to be entered. The Up & Down buttons set the enrolment number (1-20). The second menu allows previous enrol­ments to be deleted on an individual basis, as selected by the Up & Down buttons. No Match Found Fig.5: these screen shots show the menus that are brought up by pressing the Menu button on the controller. These menus let you add and delete fingerprint enrolments from the FPS database, set the scan resolution and set the door strike activation period. Other LCD readouts (not shown here) guide the enrolment procedure and indicate scanning and security errors (see panel). and this can be selected using the Up & Down buttons. Resolution & strike time The remaining two menus, for Scan Resolution and Door Strike Time are just as easy to use. Just select the menu and press the Up and Down buttons to change the settings. As mentioned previously, you can set the scan resolution to either high or low, while the strike time can be set from 1-255s. Fingerprint access Once the enrolments have been made, the unit is ready for use. When a finger is placed on the scanner and access is allowed, the LCD shows an “in brackets” guide listing how many times the user’s fingerprint has been compared against the enrolments in the database (this is shown following the ID number). A [1x] display means that the fingerprint was successfully compared with the database on the first attempt. Up to six complete fingerprint captures and comparisons with the database are allowed before it displays a No ID Match reading. When that happens, the user can remove and replace his finger on the scanner and try again. Note that the low-resolution setting may give more reliable matches than the high-resolution setting. Note also that the FPS will identify a fingerprint that’s rotated compared to the original enrolled version. In fact, the finsiliconchip.com.au gerprint can be rotated by up to 360° (Editor’s note: we are not to sure why you would want to rotate your finger by up to 360° though). THIRD MENU BUTTON PRESS The third Menu button press brings up this display. Pressing the Enter button then deletes all enrolments FOURTH MENU BUTTON PRESS The fourth menu lets you set the scan resolution to either low or high. FIFTH MENU BUTTON PRESS Installation The electric door-strike is designed to replace the normal door catch of a standard door lock. It can be installed by chiselling out the door jamb to accommodate the solenoid and then securing it in place using countersink screws. The wiring is then run from the door-strike to CON2 in the control box. The wiring polarity to the door strike is not important. As stated previously, the FPS module would normally be fitted to a blank switch-plate. This assembly would then be mounted on the access side of the door, close to the door handle. Be sure to keep it well away from any 230VAC mains cabling or wall switches etc. Be sure to waterproof the scanner if the unit is to be located outdoors. That can be done by mounting the switch-plate on a covered switch box and running a thin bead of silicone around the outside edge of the scanning lens. Don’t get any silicone on the lens though, otherwise it won’t work. The control box can be mounted adjacent to the door-strike on a wall inside the secured area. Alternatively, if you want to be able to see the LCD when using the scanner, you could arrange to have the control unit mounted The fifth menu button press brings up the Door Strike Time setting. The default is 5s but it can be set anywhere from 1-255s. behind a smash-proof glass window, with the LCD facing outside. On the other hand, if security isn’t vital, the control box could be located with the scanner. However, it would be a good idea to remove the switch PCB to prevent the unauthorised addition of fingerprint enrolments. Bezel lamp One option that you might like to consider is to mount a 12V bezel lamp on the wall-plate adjacent to the FPS module. This lamp can then be wired in parallel with the door-strike (ie, by connecting it to CON2), so that it lights whenever the door-strike is powered. The lamp bezel can use either a filament bulb or a LED. It must be wired via a 100mA fuse located in the control unit. That way, if someone pulls the lamp bezel out and tries to activate the door strike by feeding 12V back down the lamp wires, the fuse will blow and prevent access. SC November 2015  35