Digital Object Counter - Term Paper Example

Running Head: IR SENSOR DIGITAL COUNTER IR Sensor Digital Counter Name Institution Abstract This report covers an in-depth information on the design of object counter used in monitoring the counting operations in industrial applications. The counting mechanism in based on the IR interruption concept for products moving continuously on a conveyor belt. The output of the counter is displayed on a seven segment display incorporated in the design of the counter. The counter consists of a transmitters and a receiver placed at a predetermined distance from each other. The transmitter and the receiver are sensor based and operates in this combination always. The positions of the transmitter and the receiver are always opposite from each other for effective operation. Counting consists of transmitter emitting a modulated Infrared Radiation (IR) and transmitting to the receiver which receives the radiation and feeds it to an 8051 family microcontroller. An object e.g. bottle passing through the IR radiation transmitted from the transmitter to the receiver will cause an interruption that will be detected by the controller as an interruption signal. An interruptions is therefore programmed to cause an increment value on the 7 segment display and the value is equivalent to the number of objects that passes through the setup of IR sensors. Interruptions caused by objects moving in the opposite directions can also be detected by the IR sensors as well as the microcontroller and count down on the display initiated. Such a system can also be utilized in the transport industries such bus and train terminals for purposes of counting passengers and keeping the data for later use in monitoring purposes. A more advanced system can be developed by incorporating a warning capability to the system when a particular reading is or number of entities as counted by the counter is reached. For example, a warning sound or beep can be developed and programed to actuate when a maximum number of passengers is reached as recorded by the counter. Introduction Manual counting of objects especially in large scale industries is a tedious process with cases of erroneous counting cases occurring more often. Therefore, a digital object counter is a system that simplifies the entire object counting process and overcomes all the shortcomings associated with manual counting operations. Digital counting operations utilizes the properties of digital signals that can be used for further operations such as analysis. Such digital signals are always compatible with other digital devices thus enhancing its scope of usability. Digital counters automates the counting process and is fit for use even in hazardous environments where human presence is not possible as is the case in most manufacturing industries dealing with manufacture of hazardous products [1]. The mechanism of counting consists of a TSOP1738 sensor that basically detects presence of an object and subsequently send a signal to the microcontroller. The microcontroller processes the signal and feeds the output to the LCD display that bears the value of objects that have passed through the sensor. Thus the LCD displays the number of objects counted in the entire process. The purpose of TSOP1738 is to detect IR radiation and detects IR transmitted at a frequency of 38 kHz. In order the transmitter to transmit IR rays at 38 KHz, a stabilizing 555 IC is used as a multi vibrator mode. The 38 kHz output experiences minimized effects from the surroundings such as light and sound [2]. Objectives The main objectives of the experiment include; To design and object counting system. To develop the designed system at a low cost. Project description IR sensor based object counting In the past, big companies had to employ a large number of personnel to carry out object counting for the various products produced. More personal were needed to accomplish record keeping and updating ledgers regularly [3]. Human object counters were associated with errors due to the associated error loopholes associated with human labor. The most effective digital object counters are IR based digital counters incorporated with a seven segments LCD displays. The forward and reverse mode counters are the most preferred types of counters as they can increment as well as carry out count down based on the direction of flow of the objects along the conveyor. Such systems comprises of a pair of IR sensors with single or multiple microprocessors incorporated [4]. Twin IR sensors are meant to detect the direction of flow based on first signal to experience disruption between the pair of signals. Moreover, an increment of +1 or -1 based on direction of flow is only initiated when an object passes through the two rays. Indicators such as LEDs or Buzzers are incorporated to the counters in most design to indicate signal disruption or successful count by the entire counter. Reverse and forward based counters consists of IR sensors arranged as shown below. Figure 1: Arrangement of IR sensors in forward and reverse based counters Case 1 The object in case one moves from right to left and IR ray from transmitter 2 and receiver 2 setup is first disrupted and this is considered as forward movement. Forward movement results in an increment value of +1 in the counter. Case 2 In case 2, the object is moving from left to right and Ray from receiver 1 and transmitter 1 is disrupted first and this is considered as reverse movement. Reverse movement results in an count down on the counter display or an increment of -1 value. A simple arrangement of an IR based digital object counter is as shown below. Figure 2: A simple IR based object counter. Methodology Materials The following materials are required in the development of the IR based digital object counter. The requirements are categorized as hardware and software as shown below. Hardware requirements 8051 series microcontroller. 7-segment display. Diodes. Voltage regulator. Capacitors. Resistors. Transistor. LED. Push button. IR LED`s. IR sensors. Timer IC. Software requirements Keil Compiler. Languages: Embedded C or Assembly. Power supply The power output from the rectifier is a pulsating D.C voltage therefore, to stabilize this voltage, the output from the rectifier is fed to a filter. The filter will remove any alternating current properties in the output that may exist [1]. The rectified and stabilized D.C voltage is then fed to a voltage regulator to obtain a pure and constant D.C voltage. Figure 3: Power Supply Block Diagram Transformer Most of the components in the construction of the counter require an DC voltage power input and thus, a transformer is required to convert the 230V ac mains supply to either 5V,9V or 12V DC voltage inputs. A step up transformer is thus suited to perform this power reduction process [3]. Rectifier Power from transformer is converted into a pulsating DC by a rectifier. The rectifier is bridge based rectifier in this case. The choice of a full bridge rectifier is as a results of its ability to produce a stable power output. Filter The DC output from the rectifier is further cleaned by removing any AC ripples and helps in smoothening the DC output. A capacitive filter is used to accomplish this task with incorporation of a regulator [1]. A regulator in this case is used to ensure that the mains voltage as well as the load is kept constant. Voltage regulator The main function of a voltage regulator is basically to regulate the input voltage into any device. It regulates voltage by ensuring that there is a constant voltage level at all times. For the digital counter project under consideration, a constant power supplier of both 5V as well as 12V are required. Thus, to accomplish these requirements, 7805 and 7812 voltage are used to produce a regulated 5V and 12V respectively [4]. The numbering of the voltage regulators is conventional with the first two numbers 78 representing the positive supply for the regulator while the last two numbers represent the value of voltage output from the regulator. Variable voltage regulators are also in common use in design of various electrical systems due to the capability of the use to adjust the voltage output to their required magnitude at any time. The variable voltage regulator is commonly referred to as variable bench power supply and is especially used in testing of the designs [2]. Therefore, despite of the common use of the dedicated voltage regulator like the two mentioned above, variable voltage regulators are far much handy and comes with many more merits. Figure 4: Pins of a voltage regulator. Due to the fact that most digital logic based circuits utilize 5 volts DC source, it is common to start from unregulated mains supply to achieve such power input source. Properties of a voltage regulator Table 1: Properties of voltage regulator Aspect Description Operation Produces a regulated +5V output with a maximum 1A current output. Protection Inbuilt shutdown mechanism when the IC is overheated. Complexity The regulator is simple and easy to build. Performance The regulator produces a +5V output all the time. The device has a high reliability. Components availability The components are easily available in the market. Design Testing The testing of the circuit is based on datasheet circuit provided. Construction of the circuits The arrangement of the various components within the digital object counter in the circuitry is as in the block diagram below. The diagram shows a simplified logic of how processes happens as well as their relationships in the circuits. Figure 5: The block diagram showing the flow of processes in the various components of the circuit. The diagram below shows the actual arrangement of the components of the digital object counter on a board. Note that the controller is placed in the center of the board for convenience in interconnection as well space utilization of the board. Figure 6: Actual arrangements of various hardware components on the circuit board. The entire circuit diagram is shown by the schematic contained at the appendix section of this document. The interconnection between the various components are well indicated in the circuit diagrams. Program The microcontroller is coded with instructions on how to interpret input signals from the receiver and how to initiate the entire counting procedure. The program is written in the basic C programming language and is fed to the microcontroller. The software used in writing the program should have an incorporate Keil Compiler in its infrastructure. The code used in this case is incorporated in the document at the appendix section. Conclusion The construction of the entire system done by effective implementation of the circuit schematic shown in the appendix section. The IR sensors are considered as accurate sensors and thus the counter can operate at a very high speed and still carry out the counting process with high level of accuracy. The use of digital sensor based object counters has helped salvage a lot of time and is normally incorporated within the packaging or even the manufacturing process. The system is less costly as compared to the manual counting techniques employed initially in manufacturing industries. The device operates accurately, at a high speed and without fatigue. This technology is a game changer in the industrial output with regards to counting and records keeping. References 1. Balasubramanian, P., Boyer, J. H., Boyer, J., Jones, M., Mayes, C., Plesko, G., ... & Yee, A. (2015). U.S. Patent No. 9,072,652. Washington, DC: U.S. Patent and Trademark Office. 2. Chow, K. S., Zhao, Z., & Yeung, K. F. (2016). U.S. Patent No. 9,229,580. Washington, DC: U.S. Patent and Trademark Office. 3. Balasubramanian, P., Boyer, J. H., Boyer, J., Jones, M., Mayes, C., Plesko, G., ... & Yee, A. (2015). U.S. Patent No. 9,072,652. Washington, DC: U.S. Patent and Trademark Office. 4. Boso, G., Buttafava, M., Villa, F., & Tosi, A. (2015). Low-Cost and Compact Single-Photon Counter Based on a CMOS SPAD Smart Pixel. Photonics Technology Letters, IEEE, 27(23), 2504-2507. Appendix 1. Circuit diagram schematic. 2. Program The following code is used by the microcontroller to initiate counting. #include unsigned char SSD[] = {0xc0,0xf9,0xa4,0xb0,0x99,0x92,0x82,248,128,0x90,0xc0}; unsigned char d0, d1, d2, d3 , flag = 0; unsigned int a , d , s; sbit A0 = P0^0; sbit A1 = P0^1; sbit A2 = P0^2; sbit A3 = P0^3; sbit sw = P1^0; void delay(unsigned int d) { unsigned int x,s; for(s=0;s0) { goto j2; } else if(d1>0) { goto j1; } else { goto j0; } j3: A0 = 0; A1 = 0; A2 = 0; A3 = 1; P2 = SSD[d3]; for(s=0;s Read More

Indicators such as LEDs or Buzzers are incorporated to the counters in most design to indicate signal disruption or successful count by the entire counter. Reverse and forward based counters consists of IR sensors arranged as shown below. Figure 1: Arrangement of IR sensors in forward and reverse based counters Case 1 The object in case one moves from right to left and IR ray from transmitter 2 and receiver 2 setup is first disrupted and this is considered as forward movement. Forward movement results in an increment value of +1 in the counter.

Case 2 In case 2, the object is moving from left to right and Ray from receiver 1 and transmitter 1 is disrupted first and this is considered as reverse movement. Reverse movement results in an count down on the counter display or an increment of -1 value. A simple arrangement of an IR based digital object counter is as shown below. Figure 2: A simple IR based object counter. Methodology Materials The following materials are required in the development of the IR based digital object counter.

The requirements are categorized as hardware and software as shown below. Hardware requirements 8051 series microcontroller. 7-segment display. Diodes. Voltage regulator. Capacitors. Resistors. Transistor. LED. Push button. IR LED`s. IR sensors. Timer IC. Software requirements Keil Compiler. Languages: Embedded C or Assembly. Power supply The power output from the rectifier is a pulsating D.C voltage therefore, to stabilize this voltage, the output from the rectifier is fed to a filter. The filter will remove any alternating current properties in the output that may exist [1].

The rectified and stabilized D.C voltage is then fed to a voltage regulator to obtain a pure and constant D.C voltage. Figure 3: Power Supply Block Diagram Transformer Most of the components in the construction of the counter require an DC voltage power input and thus, a transformer is required to convert the 230V ac mains supply to either 5V,9V or 12V DC voltage inputs. A step up transformer is thus suited to perform this power reduction process [3]. Rectifier Power from transformer is converted into a pulsating DC by a rectifier.

The rectifier is bridge based rectifier in this case. The choice of a full bridge rectifier is as a results of its ability to produce a stable power output. Filter The DC output from the rectifier is further cleaned by removing any AC ripples and helps in smoothening the DC output. A capacitive filter is used to accomplish this task with incorporation of a regulator [1]. A regulator in this case is used to ensure that the mains voltage as well as the load is kept constant. Voltage regulator The main function of a voltage regulator is basically to regulate the input voltage into any device.

It regulates voltage by ensuring that there is a constant voltage level at all times. For the digital counter project under consideration, a constant power supplier of both 5V as well as 12V are required. Thus, to accomplish these requirements, 7805 and 7812 voltage are used to produce a regulated 5V and 12V respectively [4]. The numbering of the voltage regulators is conventional with the first two numbers 78 representing the positive supply for the regulator while the last two numbers represent the value of voltage output from the regulator.

Variable voltage regulators are also in common use in design of various electrical systems due to the capability of the use to adjust the voltage output to their required magnitude at any time. The variable voltage regulator is commonly referred to as variable bench power supply and is especially used in testing of the designs [2]. Therefore, despite of the common use of the dedicated voltage regulator like the two mentioned above, variable voltage regulators are far much handy and comes with many more merits.

Figure 4: Pins of a voltage regulator. Due to the fact that most digital logic based circuits utilize 5 volts DC source, it is common to start from unregulated mains supply to achieve such power input source.

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