Ramsey Electronics CT255 manual Bit # Value 128

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128 times to get the most significant LED to change state just once.

Normally an 8 bit number has these significant values:

Bit #:

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Value:

128

64

32

16

8

4

2

1

 

 

 

 

 

 

 

 

 

Say bits 7, 3, and 0 are on, all others are off. The value would then be 128 + 8 + 1 or 137.

Say instead bits 6, 5, 4 and 1 are on, all others are off. Our value would then be 64 + 32 + 16 + 2 or 114.

Our display is set up to read from 0.0 degrees to 127.5 degrees in 1/2 degree steps. What we do is stick in an imaginary decimal point to the left of the LSB (least significant bit) and then divide all the numbers by 2.

Bit #:

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Value:

128/2

64/2

32/2

16/2

8/2

4/2

2/2

1/2

 

 

 

 

 

 

 

 

 

Say instead bits 6, 5, 4 and 1 are on, all others are off. Our value would then be 32 + 16 + 8 + 1 or 57, which is 1/2 of 114.0. This means that we have a temperature reading of 57 degrees!

Now since we have used 8 bits for our counter, this is considered a single byte of data. This value, with the decimal point in place, is now called a fixed-point number. This means that the decimal point can never move, even when we perform mathematical operations on it. This number is now considered a 7.1 format fixed point binary value, meaning there are seven binary digits to the left, one to the right of the decimal point.

You may have heard of fixed-point DSPs; these use the same principle, only a lot more bits, and the values never surpass 1 or –1 since they shift the decimal point all the way to the left of the MSB. If there were such a thing as an 8-bit fixed point DSP, the bit values would be as follows:

Essentially take our number from before and divide by 256, or 144/256 = 0.445. DSPs do this to prevent math from overflowing in value as you multiply and accumulate. DSPs handle this math very quickly.

Bit #:

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

Value:

128/256

26/256

32/256

16/256

8/256

4/256

2/256

1/256

 

 

 

 

 

 

 

 

 

CT255 • 11

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Contents Computemp 255 Binary Thermometer KIT Ramsey Transmitter Kits KIT Assembly Introduction CB B OA RD in CA SEBinary counter Circuit DescriptionScaling to Celsius DAC Digital to Analog ConverterADC Analog to Digital Converter? In a sense… Oh that extra count More on the ADCFor the complicated Fahrenheit design How the counter oscillator worksRestarting the conversion cycle CT255 Binary math Bit # Value 128 Some random parts, and what they do CT255 Schematic Diagram CT255 Parts Layout Diagram Semiconductors Parts Supplied with Your CT255 KITCapacitors ResistorsEnough of that ... let’s get started Ramsey LEARN-AS-YOU-BUILD KIT AssemblyCT255 Thermometer Assembly Instructions CT255 CT255 CT255 Front View LM35DZ Congratulations Assembly Instructions for Custom CaseUSE of Your Computemp Still Having TROUBLE? Troubleshooting GuideConclusion Ramsey Kit Warranty Fishers Station Drive Victor, New York Phone 585 Required ToolsAdditional Suggested Items Ramsey ELECTRONICS, INC

CT255 specifications

The Ramsey Electronics CT255 is a versatile and advanced communication tool designed for radio enthusiasts and professionals alike. As a 2-meter FM transceiver, it is known for its robust performance and extensive feature set, making it ideal for both casual users and serious operators.

One of the standout features of the CT255 is its compact design, allowing for easy integration into various environments such as home stations or portable setups. The unit is built with user-friendliness in mind, featuring an intuitive interface with a clear display and easily accessible controls. This ensures that users can quickly tune into their desired frequencies and modify settings without extensive technical knowledge.

The CT255 operates on a frequency range from 144 to 148 MHz, providing access to the popular 2-meter amateur radio band. This frequency capability is complemented by an impressive output power of up to 25 watts, ensuring robust communication over extended distances. It also includes a built-in automatic repeater shift, which simplifies contacts through repeaters, making it an excellent choice for those looking to enhance their communication range.

In terms of technology, the CT255 employs advanced digital signal processing (DSP), which significantly improves audio clarity and reduces background noise. This makes communication clearer, even in less-than-ideal conditions. Additionally, the transceiver features an array of scanning functions, including memory scan and priority scan, allowing users to monitor multiple channels effortlessly.

The CT255 comes equipped with multiple memory channels, enabling easy access to frequently used frequencies. This feature is particularly useful for users who participate in various nets or have multiple repeaters they commonly contact. Moreover, the unit supports CTCSS and DCS tones, which adds an extra layer of privacy and reduces interference from unwanted transmissions.

Safety and durability are also key characteristics of the CT255. The robust construction ensures it can withstand the rigors of regular use, making it suitable for field operations. It is designed with heat dissipation features to prevent overheating during prolonged use, ensuring reliability during critical communications.

In conclusion, the Ramsey Electronics CT255 is a well-rounded transceiver that brings together advanced technology, user-centric design, and excellent performance. Its range of features makes it an appealing choice for radio amateurs seeking a dependable and efficient communication solution. Whether for casual chatting or emergency communications, the CT255 stands out as a reliable tool that meets the demands of modern radio users.
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