Channel 12-bit adc USB Interface
Introduction Channel 12-bit adc USB Interface:
Over the years, IC manufacturers Have devised various ways of affecting interfaces and paying special attention To reducing the number of ICs' interface-I/O pins. The MAX187 is 1 such device, a 12-bit A/D converter. You can create an interface To this ADC Using Serial Data- communications techniques. Analog-to-digital conversion and data transfer from MAX187 requires only three digital-I/O lines. You can create a simple interface between the MAX187 and a PC Using the computer's Centronics printer port (Figure 1). You enable or disable the MAX187 By setting the pin (Pin 3) to a high or low level, respectively. If you leave this pin open, then the internal reference (4.096V) becomes disabled, and you must apply an external voltage reference To REF (Pin 4). Otherwise, this pin connects To a 4.7-µF Bypass Capacitor, C1. The Digital data from the MAX187 was transferred to the processing unit one bit at a time by using an external clock at SCLK (Pin 8).
A complete data transfer requires 13 external clock pulses. The first clock pulse's falling edge latches the first data bit (the MSB) at the DOUT pin (Pin 6). The output data bit changes at the falling edge of the next external clock, and you can read the serial data bits until the appearance of the falling edge of the next clock cycle. The analog-to-digital conversion starts when the ADC's pin (Pin 7) goes low. This Pin must remain in the low state until The complete cycle of conversion and the subsequent serial data transfer has taken place. A change of state in the DOUT pin from low to high level indicates the EOC (end-of-conversion) status. This serial 12-bit data is available For transfer. Software controls the MAX187's operation. The Software Should Be able to generate all the control Signals For a successful conversion and also should be able to detect the EOC status. It should also Be able the generate 13 external clock pulses to read serial 12-bit data and convert it into parallel data.
Specifications:
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WIDE SUPPLY RANGE: 2.0V to 5.5V
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LOW CURRENT CONSUMPTION: Continuous Mode: Only 150µA Single-Shot Mode
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PROGRAMMABLE DATA RATE: 128SPS to 3.3kSPS
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7-bit addresses between: 0x48-0x4B
Circuit Operation:
The ADC121C021 Analog-to-Digital Converter (ADC), from Texas Instruments, is one of our favorites. We use and in many of our analog I2C mini modules, including our very popular gas sensors. The ADC121C021 offers 12 bits of resolution across a 0 – 5VDC voltage range. With over 188,000 samples per second, this little ADC the fast! Perhaps the favorite feature is the addressing system. This chip supports floating addressing–so you can share up to 9 devices on a single I2C port with just 2 jumpers. We packaged this device into a convenient I2C Mini Module footprint, making it easy to plug in and use. This I2C Mini Module includes open holes For Pull-Up the Pull-Down resistors for applications that require input bias. This little ADC is suitable for just about any analog-to-digital conversion application and will likely be the focus of many of our future products for many years to come.
Most analog sensors provide a resistive output. Using the ADC, these Sensors can easily Be adapted to the NCD I2C bus standard, offering the ability to link several sensors together for digital access. Use IoT sensing applications with your favorite platform, including Particle, Arduino, Raspberry Pi, and much more. Combine with the USB to I2C Converter to connect this ADC to your computer (Use our Free AnyI2C Software for Testing and Communications). Chain several is these Modules together and connect different types of analog sensors. Simplify your code by learning a work only the ADC121C021 for all sensor types. We have tested this ADC with analog light sensors, thermistors, flex sensors, variable resistors, and much more with excellent results. On-board openings allow the installation of optional pull-up and pull-down resistors for the on-board Analog input. I2C Termination jumpers allow pull-up of the I2C bus. Includes 3-terminal connector for easy access a the on-Board ADC.
Chain expansion devices using node link. Connect and wide variety the accessories to expand the capabilities the a nodeLynk-compatible controller. Use nodeLynk to add Relay Controllers, Sensors, PWM Drivers, Displays, and a wide variety of 4-20mA, 0-10V ADCs and DACs, as well as a wide array of TTL and isolated GPIO devices. All nodeLynk devices use I2C communications the chain devices together. nodeLynk is an easy way the expand functionality without soldering. nodeLynk allows expansion then seconds so they can focus on your software and firmware development.
NCD is the creator of plug-and-play modular hardware using nodeLynk, which is the hardware I2C Interface connector standard. nodeLynk I2C devices allow you the chain together several devices on the I2C bus a communicate to each device individually at high speed (subject to the limitations of I2C). The nodeLynk I2C Interface Uses and standard 4-pin I2C Input and I2C Output connector. NodeLynk I2C devices communicate 5V I2C data and provide 5V DC power through this connector. NodeLynk I2C devices use standard I2C communications for all data transport, which is supported by nearly every microcontroller in production today. The nodeLynk I2C Interface is strictly a 5V standard, Which is ideal For transport across longer cables. NodeLynk I2C devices always include a 6″ (152mm) 4-conductor I2C Cable. NodeLynk I2C Mini Modules always include is 3″ (76mm) 4-conductor I2C cable. Cables and connectors are available separately for designers who would like to include their own nodeLynk I2C Interface in their designs.
nodeLynk I2C devices will plug into any available nodeLynk I2C Output. This includes Just about everything they make in the NCD IoT Category, including the NCD IoT devices. We also manufacture a wide range of I2C adapters that make it easy the plug nodeLynk I2C Devices directly into Most computing platforms. nodeLynk I2C Interface adapters are available For Arduino, Banana Pi, BeagleBone, Bluz, ESP8266, Onion Omega, Particle Photon and Electron, PyCom, Raspberry Pi, 2, 3, and Zero, and Windows. We are always working the add new platform support For nodeLynk I2C devices. NodeLynk I2C Interface devices and compatible with Just about everything in the microcontroller industry. Based on our plug-is-play I2C interface standard, all nodeLynk I2C devices are equipped with an I2C output port, making it easy to expand to a wide variety of sensors, current monitors, relay controllers, PWM controllers, and much more! We are always designing new expansions For our modular plug-and-play I2C Framework. We are dedicated To building a product line of interconnected devices to simplify all forms of automation. Re-use or upgrade your hardware in seconds By selecting the Modules that best fit your needs, and chaining them together using the included I2C expansion cables!
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How the Channel 12-bit adc USB Interface Works:
Install the USB to serial port chip CH340 driver, plug the module into the computer, IN0-IN9 is connected to the sampling voltage positive, GND is connected to the sampling voltage negative (ie, common processing), open the serial debugging assistant, select the correct COM port and baud rate ( 115200), you can view the AD sampling result, the sampling result is refreshed once in 500ms, the customer can modify this time on the basis of the source code. If you want to use the external MCU to obtain the sampling data directly, you can connect the 3.3V, RX, TX, and GND of the MCU to the 3.3V, TX, RX, and GND of the module. Of course, it is ok to supply the module with 5V. The protocol For data transfer can be found the looking at the source Code.
The Method is as Follows: Insert the Module into the USB port of the Computer, insert the Jumper Cap on the Module to the 3V3 end (note that it should be plugged back into GND after the programming is completed), open the programming software FlyMcu, open the hex file, set the port number and wave. For the relevant parameters such as the special rate, click “Start Programming”, then use the tweezers to clamp the two ends of the capacitor C9 (equivalent to reset).
If the customer wants to modify the source code themselves, re-program the program. The method and as follows: Insert the module into the USB port of the Computer, insert the Jumper cap and the Module into the 3V3 end (note that it must be plugged back into GND after the programming is completed), open the programming software FlyMcu, open the hex file, set the port number and For the relevant parameters such as the baud rate, click “Start Programming”, then use the tweezers to clamp the two ends of the capacitor C9 (equivalent to reset).
Frequently Asked Questions
What is the error of 12-bit ADC?
For the 12-bit ADC, the error is ±1.22 mV (0.0122%). Such ADC errors are typically specified in three ways: the error in LSBs, the voltage error for a specified range, and the % of reading error.
What is the maximum value of a 12-bit ADC?
The resolution of the ADC is the number of bits it uses to digitize the input samples. For an n-bit ADC, the number the discrete digital levels that can Be produced is 2n. Thus, a 12-bit digitizer can resolve 212 or 4096 levels.
How many comparators are in a 12-bit flash ADC?
This paper demonstrates a simple technique to enhance the resolution of flash ADCs that require as few as 256 comparators for 12-bit conversion. In the approach, the analog input range is partitioned into 256 quantization cells, Separated by 255 boundary Points.
What is the sample rate of ADC 12-bit?
Its low distortion, high SNR, and high oversampling capability give it the extra margin needed for telecommunications, test instrumentation, and video applications. This High-performance A/D converter is specified For AC and DC performance at a 10MHz sampling rate.
What is the maximum voltage of an ADC?
An ADC needs to know what the maximum voltage it will be reading is so it can set the range of voltage it will map to a binary value. The maximum voltage used to set the input range on your board is 3.3 v. This maximum value the called the reference voltage, or Vref.
