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Intel IoT Battlefield, DeKUT

Intelligent Transportation: Make Driving Safer and More Efficient

Internet of Everything

It’s not a Shabaab watch tower, it’s a Base Transceiver Station

Several people have been wondering about the white tower being erected in the university (Dedan Kimathi University of Technology). Due to current wave of terrorist attack, others think it’s a Shabaab watch tower. One school of though is for this: “The University have heightened security at all the gates, but they are not stopping at that, they have set this to help see the Shabaab from a long range”. Well that isn’t true. So what is it?

The cellular tower is a temporary telecommunication infrastructure that will facilitate (boost) wireless communication between a subscriber device/equipment or operator devices and a telecom operator network (Safaricom) during the beatification of Sister Irene Stefani. Thousands of people are expected to grace the event. User equipment are devices like mobile phones, wireless internet devices while operator devices are devices such as GSM(Global System for Mobile Communications), Code Division Multiple Access (CDMA) ,TDMA platform, Wi-Fi and WiMAX  (Worldwide Interoperability for Microwave Access)  among others.

The entire base station consist of a cellular tower and a BTS, also known as a base station (BS), radio base station (RBS) or node B (eNB). Most people confuse the tower and the entire base station to be the BTS.

This is the Base Transceiver Station (BTS)

The BTS comprises of a fix radio Transceiver (TRX) which handles transmission and reception of signals; sending and reception of signals to or from higher network entities, a Combiner which Combines feeds from several TRXs so that they could be sent out through a single antenna thus reducing the number of antennas that need be installed, a Power amplifier which aids in signal amplification from TRX for transmission through the antenna, a Duplexer which is used for separating, sending and receiving signals to or from the antenna and an Antenna which is an external part of the BTS

The temporary station receives a signal from a parent base station controller (BSC) at Kamakwa through the dish. A BTS is usually placed in the center of a cell serving as a single cell. It is assigned a Cell Identity. The cell identity is 16-bit number (double octet) that identifies that cell in a particular Location Area.

 In a typical structure, there are three sectors served by separate antennas. Each sector has a separate direction of tracking, typically of 120° sector of an area with respect to the adjacent ones .Usually a tower with 3 BTSs will accommodate all 360 degrees around the tower, however, depending on geography and user demand of an area, other orientations may be used including orienting the antennas to serving sectors of 180° separation to one another.

The BTS equipment are usually housed in a shelter which protects the telecoms equipment from external conditions such as dust, corrosion, rust or even theft.

On the cellular tower, we have remote radio unit (RRU), 2G, 3G and the Antenna. The RRU include a cyclic prefix (CP) module with a CP adder for downlink channel processing and a CP remover for uplink channel processing. The RRU can be configured to communicate with a base band unit (BBU) via a physical communication link and can communicate with a wireless mobile device via an air interface.

Sitting on the antenna and pointing at the RRU. All of them are lifted to the cellular tower .They will be  bolted to the H-frame.

On health risks, there is no substantial link between exposure to electromagnetic signals at the level of BTS and mobile telephone handsets transmission. 

MOBILE CONTROLLED 24-HRS DIGITAL CLOCK DESIGN FROM SCRATCH

In this project, we will help you design and build a digital clock with 24 hour count time which can be adjusted using a mobile app. The clock runs from 00:00 to 23:00 and then back to 00:00. Our display will have eight digits, two digits for the minute’s section and two for the hour section. The specialty of this clock is that it has very low power consumption and condensed layout.

We have used a simple 0-9 counter for the ones digit of minutes display and a 0-5 counter for the tens digit display of minutes. For the unit’s digit of hour, a resettable 0-9 counter has been used, and for the ten’s digit of hour a resettable JK-flip-flop has been used. In addition to these, a few NAND gates and OR gates have been used to ensure proper functioning of the clock.

There is only one input for the entire system: the clock input into the 0-9 counter used for the ones digit of minute display. The clock inputs for the other blocks are derived from the output of the previous blocks.

We have also designed a four 7-segment decoder which can be used for the actual display of digits as we see on a real digital clock. The outputs of the decoders would be connected to a seven segment common anode display.

HARDWARE DESIGN

In this part, you will implement your software/theoretical design on a breadboard for prototyping before finally implementing it on a strip board (electronics prototyping board).  In designing and simulating the clock, the following sections will be designed separately:

1.         Power Supply
2.        Pulse Generator
3.        Clock Circuit
4.        Display Circuit
5.        Integration

POWER SUPPLY DESIGN

Our electronics design will need a 5 - 7V supply. We will design a power supply that provides +5V output. The transformer steps down 220V to 12V and a bridge network of 4 diodes rectifies it. The 7805 regulator serves the purpose of regulating the power supply to produce a steady 5V DC.

Required Instruments:

A transformer (110/220V   50/60    AC 12 1A)

Capacitors: 470uF and 100uF

A 7805 regulator

4 diodes: (1N 4007)

Breadboards (approximately 5)

Connecting wires

Connect your circuit as follows:

PULSE/SIGNAL GENERATOR

The pulse generator is the heart of the clock - the time base. We will be using NE555N timer which in a stable mode configuration continuously produces pulses at its pin 3(output) .The pulses are square wave and using a fixed resistor will give you an exact frequency of 1Hz. To vary the frequency you will have to replace the resistor with a variable resistor.

For this, you may need: a 555-timer, a well regulated power supply, the power supply designed in the previous section and some passive components which are on the diagram.

We have already simulated the designed circuit and made adjustments where necessary.

Connect your circuit as follows:

 This circuit should produce a frequency of 1Hz (equivalent to a period of 1 second). This will be used as the time base for our clock.

CLOCK CIRCUIT, DISPLAY CIRCUIT & ALARM CLOCK

This will be the circuit for extracting time information from the time base. Our time will be extracted in the HH:MM:SS format.

Use the following schematic to design the clock, display and alarm circuit:

We have done the circuit design and calculations, I have also simulated the circuit and nearly made all the necessary changes and appropriate adjustments. During the design implementation, following IC data sheets will be very important. This is simple, all you need to know is to the number on the components and a good internet connection.

You may need: 4 counters (ICs)-74LS90, logic AND gates (ICs) 74LS08, Drivers IC 74LS47D and your power supply. You will also need 6 segment display (Common anode) and a resister (220 Ohms) before each of the displays.

For display circuit you will require the following components: display drivers and seven segment displays (make appropriate choice between common anode and common cathode), your power supply and some resistors.

On the last part is the alarm clock section, the kind of alarm clock designed here will be the type that goes off after every 4 hours. Here you will need comparators, a buzzer, a tone generator (most likely a 555 astable circuit), your power supply and some logic gates (ICs).

CLOCK SETTING

For manual time setting/resetting we need a manual switch .We will need two debouncing circuits to help us input a manual switch signal into a digital circuit; one for the hours and another for the minutes. With debouncing circuits, single press doesn't appear like multiple presses.

Requirements:

2-push-button

2-Schmitt trigger-74HC14

 2- 4.7K Resistors & 2-100K Resistor

2 diodes

2-10 uF capacitor

Here's the circuit:

 The basic idea is to use a capacitor to filter out any quick changes in the switch signal.

The first thing you'll notice is there's a diode in the circuit. That helps the capacitor to charge up quickly when the switch is opened after being closed.

The second thing you'll notice is R2. This resistor prevents the capacitor from dumping its charge into the switch contacts and burning or pitting them. The two extra components won't significantly affect the timing of the circuit when it's in use, so you don't have to recalculate all your values.

We have successfully designed the 24hr digital clock, in the next blog, we are going to enter into the world of IoT (Internet of Things) and control our clock using our mobile phones. Keep checking this blog to find more updates.

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