A Smart Sensor Interface for Industrial Monitoring using ARM 2014-15

A Smart Sensor Interface for Industrial Monitoring using ARM 2014-15

CHAPTER 1INTRODUCTION1.1 IntroductionIntelligent wireless sensor-based controls have drawn attention of the industry on account of reduced costs, better power management, ease in maintenance, and effortless deployment in remote and hard-to-reach areas. They have been successfully deployed in many industrial applications such as maintenance, monitoring, control, security, etc. In this research, the focus is on the issues of portability, reliability, flexibility and robustness while using wireless connectivity in industrial applications such as instrumentation and predictive maintenance, and to design a workable solution. This project expanding the scope of the applications, investigate design choices for the proposed system, and presents detailed experimental results of the implementations with their analysis. The proposed Smart Sensor Platform is an attempt to develop a generic platform with plug-and-play capability to support hardware interface, payload and communication needs of multiple sensors, and actuators. An RF link (ZigBee) facilitates communications in a point-to-point topology. The design also provides means to update operating, monitoring parameters, operational thresholds, and sensor and RF link specific firmware modules over-the-air. It is composed of two main components a sensor-wireless hardware interface and system integration framework, which facilitates the defining of interaction between sensors based on process needs. The intelligence necessary to process the sensor signals, monitor the functions against defined operational templates, and enable swapping of sensor and RF link, resides on the microcontroller of the hardware interface.A variety of industrial sensors (temperature, Gas detection, colour change and light etc.) have been interfaced and successfully tested with the platform. The organization of this project covers potential industrial applications to benefit by wireless connectivity, and the supply chain management.1.2 Literature surveyWireless technology is a constantly evolving area, especially for industrial users, which often makes wireless infrastructure deployments in industrial environments difficult. Before taking on such a project, facility operators need to be aware of the challenges from rapid prototyping of wireless sensors in an industrial environment and the best practices for radio frequency (RF) design in complex or harsh RF environments, such as manufacturing, industrial, or power generation facilities.The business drivers for this type of project can most often be associated with the transition from conditioned-based monitoring to performance-based monitoring. In addition, the data points are usually collected manually, and the lack of continuous data does not allow for complex analytics or modelling.Implementing wireless sensor sets create benefits across multiple areas. For instance, scarce engineering resources can focus on data analysis rather than data collection from disparate sources and can concentrate on few degrading trends rather than every trend. Maintenance workers can reduce or entirely eliminate selected data collection rounds through placement of wireless monitoring sensors. The need for deep technical capabilities on-site and concerns about inconsistent diagnostic results due to experience levels of individual employees can be greatly reduced.By leveraging wireless technologies, operators can acquire critical component monitoring data in significantly higher volumes, reduce staff impact of making collection rounds, and focus those resources on data analysis and prognostics of issues. By implementing a wireless infrastructure and using it for the rapid deployment of new sensor types, operators can create significant advances in critical component monitoring.1.3 Problem StatementIn any industrial process there may be one or more physical quantities are to be measured simultaneously. In such cases it is required to take reading of their values at regular interval and for that a person has to seat there and monitor it continuously. If there are so many such processes then they require more man power. This is really wastage of human power. Also the premises where the actual process runs may be hazardous or may be uncomfortable for mankind. To send these values using pair of wires and connections but in that case there will be a complex network of lots of wires that may lead to chaos.1.4 Scope of the ProjectTo monitor all these physical quantities from central control room where hardly two or three persons can easily monitor all the sensors, stores and update the records. All the physical quantities that are measured at one place, their values are sent wirelesslyto a remote location.The values are sent at regular intervals. Their values are displayed at both ends without change. Along with there are indication for changing in values. So this system is also useful in taking some decisions. So let us see how the concept is utilized.

CHAPTER 2A Smart Sensor Interface for Industrial Monitoring using ARMIntelligent wireless sensor-based controls have drawn attention of the industry on account of reduced costs, better power management, ease in maintenance, and effortless deployment in remote and hard-to-reach areas. They have been successfully deployed in many industrial applications such as maintenance, monitoring, control, security, etc. In this research, the focus is on the issues of portability, reliability, flexibility and robustness while using wireless connectivity in industrial applications such as instrumentation and predictive maintenance, and to design a workable solution.

NODE SECTION

Fig 2.1 Node sectionMONITORING SECTION

ZIGBEEPC

Fig 2.2 Monitoring SectionThe block diagram shows transmitter side of the system. As shown in the block diagram, system needs, ARM LPC2129 controller, 2x16 LCD, buzzer, ZigBee module, CO2 sensor and a colour sensor. LCD is used to display data, Buzzer is used to alert the user in case of high temperature, co2 sensor is used to detect excessive carbon element and colour sensor detects colours (only fundamental colours) finally ZigBee to transmit all measured values. Functional description of system is as follows:

Initially, to measure the temperature and light values, temperature sensor, LDR and is used. Temperature sensor will be connected to channel 0 of ADC and LDR will be connected to Channel 1 of ADC module which is built in in controller. Digital conversion of these two analog inputs will be done and result will collected and displayed on the LCD. Later, status of CO2 sensor as well as COLOUR sensor will be checked and displayed on the LCD. COLOUR sensor works in 3 different modes i.e., RED, GREEN and BLUE mode. In RED mode, red colour will be having higher frequency than any other colour, similarly in GREEN mode green colour will be having higher frequency and in BLUE mode blue colour will be having higher frequency, thus based on frequencies COLOUR sensor will detect the colours. If temperature goes higher than the specified value a buzzer will become on for sometimes to alert user. Finally, all the measured data, status of CO2 and colour will be transmitted through ZigBee using serial communication with the baud rate of 9600.

In Receiver side values will be received through ZigBee and displayed on the screen thus the system can be monitored.

2.1 LPC2129 MICROCONTROLLERThe LPC2129 are based on a 16 bit ARM7TDMI-SCPU with real-time emulation and embedded trace support, together with 128 kilobytes (kB) of embedded high speed flash memory. A 128-bit wide memory interface and unique accelerator architecture enable 32-bit code execution at maximum clock rate. For critical code size applications, the alternative 16-bit Thumb Mode reduces code by more than 30 % with minimal performance penalty.With their compact 64 pin package, low power consumption, various 32-bit timers, 4-channel 10-bit ADC, 2 advanced CAN channels, PWM channels and 46 GPIO lines with up to 9 external interrupt pins these microcontrollers are particularly suitable for automotive and industrial control applications as well as medical systems and fault-tolerant maintenance buses. With a wide range of additional serial communications interfaces, they are also suited for communication gateways and protocol converters as well as many other general-purpose applications. The features of the lpc2129 microcontroller is given below:

16/32-bit ARM7TDMI-S microcontroller in a tiny LQFP64 package. 16 kB on-chip Static RAM. 128/256 kB on-chip Flash Program Memory. 128-bit wide interface/accelerator enables high speed 60 MHz operation. In-System Programming (ISP) and In-Application Programming (IAP) via on-chip boot-loader software. Flash programming takes 1ms per 512 byte line. Single sector or full chip erase takes 400ms. Embedded ICE-RT interface enables breakpoints and watch points. Interrupt service routines can continue to execute while the foreground task is debugged with the on-chip Real Monitor software. Embedded Trace Macro cell enables non-intrusive high speed real-time tracing of instruction execution. Two interconnected CAN interfaces with advanced acceptance alters. Four channel 10-bit A/D converter with conversion time as low as 2.44ms. Multiple serial interfaces including two UARTs (16C550), Fast C (400 Kbits/s) and two SPIs 60 MHz maximum CPU clock available from programmable on-chip Phase-Locked Loop with settling time of 100ms. Vectored Interrupt Controller with configurable priorities and vector addresses. Two 32-bit timers (with four capture and four compare channels), PWM unit (six-outputs), Real Time Clock and Watchdog. Single-chip 16/32-bit microcontrollers Up to forty-six 5 V tolerant general purpose I/O pins. Up to nine edge or level sensitive external interrupt pins available. On-chip crystal oscillator with an operating range of 1 MHz to 30 MHz Two low power modes, Idle and Power-down. Processor wake-up from Power-down mode via external interrupt. Individual enable/disable of peripheral functions for power optimization.Architecture of LPC2129 is given below:

Fig 2.1.1 Block Diagram

The LPC2129 consists of an ARM7TDMI-S CPU with emulation support, the ARM7 Local Bus for interface to on-chip memory controllers, the AMBA Advanced High-performance Bus (AHB) for interface to the interrupt controller, and the VLSI Peripheral Bus (VPB, a compatible superset of ARMs AMBA Advanced Peripheral Bus) for connection to on-chip peripheral functions. The LPC2129 configures the ARM7TDMI-S processor in little-endian byte order.AHB peripherals are allocated a 2 megabyte range of addresses at the very top of the 4 gigabyte ARM memory space. Each AHB peripheral is allocated a 16 kilobyte address space within the AHB address space. LPC2129 peripheral functions (other than the interrupt controller) are connected to the VPB bus. The AHB to VPB bridge interfaces the VPB bus to the AHB bus. VPB peripherals are also allocated a 2 MB range of addresses, beginning at the 3.5 GB address point. Each VPB peripheral is allocated a 16 kilobyte address space within the VPB address space.The connection of on-chip peripherals to device pins is controlled by a Pin Connection Block. This must be configured by software to fit specific application requirements for the use of peripheral functions and pins.LPC2129

Fig 2.1.2 Pin Diagram of LPC2129.

The LPC2129 incorporate a 256 kB Flash memory system. This memory may be used for both code and data storage. Programming of the Flash memory may be accomplished in several ways: over the serial built-in JTAG interface, using In System Programming (ISP) and UART0, or by means of In Application Programming (IAP) capabilities. The application program, using the In Application Programming (IAP) functions, may also erase and/or program the Flash while the application is running, allowing a great degree of flexibility for data storage field firmware upgrades, etc.The LPC2129 provide a 16 kB static RAM memory that may be used for code and/or data storage. The SRAM supports 8-bit, 16-bit, and 32-bit accesses. The SRAM controller incorporates a write-back buffer in order to prevent CPU stalls during back-to-back writes. The write-back buffer always holds the last data sent by software to the SRAM. This data is only written to the SRAM when another write is requested by software (the data is only written to the SRAM when software does another write). If a chip reset occurs, actual SRAM contents will not reflect the most recent write request (i.e. after a "warm" chip reset, the SRAM does not reflect the last write operation). Any software that checks SRAM contents after reset must take this into account. Two identical writes to a location guarantee that the data will be present after a Reset. Alternatively, a dummy write operation before entering idle or power-down mode will similarly guarantee hat the last data written will be present in SRAM after a subsequent Reset.

2.2 LM35 Precision Centigrade Temperature Sensors

The LM35 series are precision integrated-circuit temperature sensors, with an output voltage linearly proportional to the Centigrade temperature. Thus the LM35 has an advantage over linear temperature sensors calibrated in Kelvin, as the user is not required to subtract a large constant voltage from the output to obtain convenient Centigrade scaling. The LM35 does not require any external calibration or trimming to provide typical accuracies of C at room temperature and C over a full 55C to +150C temperature range. Low cost is assured by trimming and calibration at the wafer level. The low output impedance, linear output, and precise inherent calibration of the LM35 make interfacing to readout or control circuitry especially easy. The device is used with single power supplies, or with plus and minus supplies. As the LM35 draws only 60 A from the supply, it has very low self-heating of less than 0.1C in still air. The LM35 is rated to operate over a 55C to +150C temperature range, while the LM35C is rated for a 40C to +110C range (10 with improved accuracy). The LM35 series is available packaged in hermetic TO transistor packages, while the LM35C, LM35CA, and LM35D are also available in the plastic TO-92 transistor package. The LM35D is also available in an 8-lead surface-mount small outline package and a plastic TO-220 package.

The FEATURES of LM35 is given below: Calibrated Directly in Celsius (Centigrade) Linear + 10 mV/C Scale Factor 0.5C Ensured Accuracy (at +25C) Rated for Full 55C to +150C Range Suitable for Remote Applications Low Cost Due to Wafer-Level Trimming Operates from 4 to 30 V Less than 60-A Current Drain Low Self-Heating, 0.08C in Still Air Nonlinearity Only C Typical Low Impedance Output, 0.1 for 1 mA Load

Fig 2.2.1 LM35 Temperature Sensor

The LM35 is applied easily in the same way as other integrated-circuit temperature sensors. Glue or cement the device to a surface and the temperature should be within about 0.01C of the surface temperature.This presumes that the ambient air temperature is almost the same as the surface temperature. If the air temperature were much higher or lower than the surface temperature, the actual temperature of the LM35 die would be at an intermediate temperature between the surface temperature and the air temperature, which is especially true for the TO-92 plastic package where the copper leads are the principal thermal path to carry heat into the device, so its temperature might be closer to the air temperature than to the surface temperature.To minimize this problem, ensure that the wiring to the LM35, as it leaves the device, is held at the same temperature as the surface of interest. The easiest way to do this is to cover up these wires with a bead of epoxy which will insure that the leads and wires are all at the same temperature as the surface, and that the temperature of the LM35 die is not affected by the air temperature.The Parameters of the LM35 is given by:

Table 2.1

2.3 LIGHT DEPENDENT RESISTOR (LDR Sensor)A Light-dependent resistor (LDR) or photocell is a light-controlled variable resistor. The resistance of a photo-resistor decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor can be applied in light-sensitive detector circuits, and light- and dark-activated switching circuits.A photo-resistor is made of a high resistance semiconductor. In the dark, a photo-resistor can have a resistance as high as a few meg-ohms (M), while in the light, a photo-resistor can have a resistance as low as a few hundred ohms. If incident light on a photo-resistor exceeds a certain frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electrons (and their whole partners) conduct electricity, thereby lowering resistance. The resistance range and sensitivity of a photo-resistor can substantially differ among dissimilar devices. Moreover, unique photo-resistors may react substantially differently to photons within certain wavelength bands.

Fig 2.3.1 LDR symbol and material used

A photoelectric device can be either intrinsic or extrinsic. An intrinsic semiconductor has its own charge carriers and is not an efficient semiconductor, for example, silicon. In intrinsic devices the only available electrons are in the valence band, and hence the photon must have enough energy to excite the electron across the entire bandgap. Extrinsic devices have impurities, also called dopants, added whose ground state energy is closer to the conduction band; since the electrons do not have as far to jump, lower energy photons (that is, longer wavelengths and lower frequencies) are sufficient to trigger the device. If a sample of silicon has some of its atoms replaced by phosphorus atoms (impurities), there will be extra electrons available for conduction. This is an example of an extrinsic semiconductor.Photo-resistors are less light-sensitive devices than photodiodes or phototransistors: the two latter components are true semiconductor devices, while a photo-resistor is a passive component and does not have a PN-junction. The photo-resistivity of any photo-resistor may vary widely depending on ambient temperature, making them unsuitable for applications requiring precise measurement of or sensitivity to light.Photo-resistors also exhibit a certain degree of latency between exposure to light and the subsequent decrease in resistance, usually around 10 milliseconds. The lag time when going from lit to dark environments is even greater than, often as long as one second. This property makes them unsuitable for sensing rapidly flashing lights, but is sometimes used to smooth the response of audio signal compression. The LDR characteristic curve is shown below:

Fig 2.3.2 resistance VS Illumination

The cell resistance increases with increasing light intensity Light dependent resisters have a particular property in that they remember the lighting conditions in which they have been stored. This memory effect can be minimised by storing LDRs in light prior to use. Light storage reduces equilibrium time to reach steady resistance values.

2.4 MQ-7 (CO2)A carbon dioxide sensor or CO2 sensor is an instrument for the measurement of carbon dioxide gas. The most common principles for CO2 sensors are infrared gas sensors (NDIR) and chemical gas sensors. Measuring carbon dioxide is important in monitoring indoor air quality, the function of the lungs in the form of a capnograph device, and many industrial processes.Chemical CO2 gas sensors with sensitive layers based on polymer- or heteropolysiloxane have the principal advantage of very low energy consumption, and can be reduced in size to fit into microelectronic-based systems. On the downside, short- and long term drift effects as well as a rather low overall lifetime are major obstacles when compared with the NDIR measurement principle. Most CO sensors are fully calibrated prior to shipping from the factory. Over time, the zero point of the sensor needs to be calibrated to maintain the long term stability of the sensor.

Fig 2.4.1 MQ-7 (CO2)The surface resistance of the sensor Rs is obtained through effected voltage signal output of the load resistance RL which series-wound. The relationship between them is described: Rs\RL = (Vc-VRL) / VRL

Fig 2.4.2 Graph of CO2 SensorFig. 2.4.2 shows alterable situation of RL signal output measured by using Fig 2.4.3 circuit output signal when the sensor is shifted from clean air to carbon Dioxide (CO2) output signal measurement is made within one or two complete heating period (2.5 minute from high voltage to low voltage).Sensitive layer of MQ-7 gas sensitive components is made of SnO2 with stability, so, it has excellent long term stability. Its service life can reach 5 years under using condition. The feature of the MQ-7 is given by:

High sensitivity to carbon dioxide. Stable and long life.

The STANDARD CIRCUIT OF MQ-7 as shown in below Fig 2.4.3

Fig 2.4.3 standard measuring circuit of MQ-7The sensitive components consist of 2 parts. One is heating circuit having time control function (the high voltage and the low voltage work circularly). The second is the signal output circuit; it can accurately respond changes of surface resistance of the sensor.

Resistance value of MQ-7 is difference to various kinds and various concentration gases. So, when using these components, sensitivity adjustment is very necessary. We recommend that you calibrate the detector for 200ppm CO in air and use value of Load resistance that (RL) about 10 K (5K to 47 K). When accurately measuring, the proper alarm point for the gas detector should be determined after considering the temperature and humidity influence. The sensitivity adjusting program: a. Connect the sensor to the application circuit. b. Turn on the power; keep preheating through electricity over 48 hours. c. Adjust the load resistance RL until you get a signal value which is respond to a certain carbon monoxide concentration at the end point of 90 seconds. d. Adjust the another load resistance RL until you get a signal value which is respond to a CO concentration at the end point of 60 seconds . The application of MQ-&: They are used in gas detecting equipment for carbon monoxide (CO) in family and industry or car.

2.5 COLOR LIGHT-TO-FREQUENCY CONVERTERThe TCS3200 programmable colour light-to-frequency converters that combine configurable silicon photodiodes and a current-to-frequency converter on a single monolithic CMOS integrated circuit. The output is a square wave (50% duty cycle) with frequency directly proportional to light intensity (irradiance). The full-scale output frequency can be scaled by one of three pre-set values via two control input pins. Digital inputs and digital output allow direct interface to a microcontroller or other logic circuitry. Output enable (OE) places the output in the high-impedance state for multiple-unit sharing of a microcontroller input line. In the TCS3200, the light-to-frequency converter reads an 8 x 8 array of photodiodes. Sixteen photodiodes have blue filters, 16 photodiodes have green filters, 16 photodiodes have red filters, and 16 photodiodes are clear with no filters.The four types (colours) of photodiodes are interdigitated to minimize the effect of non-uniformity of incident irradiance. All photodiodes of the same colour are connected in parallel. Pins S2 and S3 are used to select which group of photodiodes (red, green, blue, clear) are active. Photodiodes are 110m x 110m in size and are on 134m centres.

Fig 2.5.1 Colour sensorThe features of colour Sensor is given below: High-Resolution Conversion of Light Intensity to Frequency Programmable Colour and Full-Scale Output Frequency Communicates Directly With a Microcontroller Single-Supply Operation (2.7 V to 5.5 V) Power down Feature Nonlinearity Error Typically 0.2% at 50 kHz Stable 200 ppm/C Temperature Coefficient Low-Profile Lead (Pb) Free and RoHS Compliant Surface-Mount Package

Fig 2.5.2 Colour sensor functional block diagram.

The Application of Colour Sensor is given below: Power supply considerations Power-supply lines must be decoupled by a 0.01-F to 0.1-F capacitor with short leads mounted close to the device package. Input interface A low-impedance electrical connection between the device OE pin and the device GND pin is required for improved noise immunity. All input pins must be either driven by a logic signal or connected to VDD or GND they should not be left unconnected (floating). Output interface The output of the device is designed to drive a standard TTL or CMOS logic input over short distances. If lines greater than 12 inches are used on the output, a buffer or line driver is recommended. A high state on Output Enable (OE) places the output in a high-impedance state for multiple-unit sharing of a microcontroller input line. Power downPowering down the sensor using S0/S1 (L/L) will cause the output to be held in a high-impedance state. This is similar to the behaviour of the output enable pin, however powering down the sensor saves significantly more power than disabling the sensor with the output enable pin.

Photodiode type (colour) selection The type of photodiode (blue, green, red, or clear) used by the device is controlled by two logic inputs, S2 and S3.

Output frequency scaling Output-frequency scaling is controlled by two logic inputs, S0 and S1. The internal light-to-frequency converter generates a fixed-pulsewidth pulse train. Scaling is accomplished by internally connecting the pulse-train output of the converter to a series of frequency dividers. Divided outputs are 50%-duty cycle square waves with relative frequency values of 100%, 20%, and 2%. Because division of the output frequency is accomplished by counting pulses of the principal internal frequency, the final-output period represents an average of the multiple periods of the principle frequency. The output-scaling counter registers are cleared upon the next pulse of the principal frequency after any transition of the S0, S1, S2, S3, and OE lines. The output goes high upon the next subsequent pulse of the principal frequency, beginning a new valid period. This minimizes the time delay between a change on the input lines and the resulting new output period. The response time to an input programming change or to an irradiance step change is one period of new frequency plus 1 s. The scaled output changes both the full-scale frequency and the dark frequency by the selected scale factor. The frequency-scaling function allows the output range to be optimized for a variety of measurement techniques. The scaled-down outputs may be used where only a slower frequency counter is available, such as low-cost microcontroller, or where period measurement techniques are used. The choice of interface and measurement technique depends on the desired resolution and data acquisition rate. For maximum data-acquisition rate, period-measurement techniques are used. Pin diagram and description of colour sensor pin numbres is show in fig 2.15 and table 2.1 respectively.

Fig 2.5.3 Pin diagram of colour sensor.

Pin Function Descriptions PinPin name Pin Description

1GNDPower supply ground.

2OUT Output frequency

3S2Photodiode type selection inputs.

4S3Photodiode type selection inputs.

5VCCSupply Voltage.2.7-5v

6VCC Supply Voltage.2.7-5v

7S1Output frequency scaling selection inputs.

8S0Output frequency scaling selection inputs.

9LED LED CONTROL 1:ON,0:OFF

10GND Power supply ground

Table 2.2 Pin Function Descriptions

Output data can be collected at a rate of twice the output frequency or one data point every microsecond for full-scale output. Period measurement requires the use of a fast reference clock with available resolution directly related to reference clock rate. Output scaling can be used to increase the resolution for a given clock rate or to maximize resolution as the light input changes. Period measurement is used to measure rapidly varying light levels or to make a very fast measurement of a constant light source. Maximum resolution and accuracy may be obtained using frequency-measurement, pulse-accumulation, or integration techniques. Frequency measurements provide the added benefit of averaging out random- or high-frequency variations (jitter) resulting from noise in the light signal. Resolution is limited mainly by available counter registers and allowable measurement time. Frequency measurement is well suited for slowly varying or constant light levels and for reading average light levels over short periods of time. Integration (the accumulation of pulses over a very long period of time) can be used to measure exposure, the amount of light present in an area over a given time period.

2.6 ZIGBEEZigbee modules (Tarang modules) are designed with low to medium transmit power and for high reliability wireless networks. The modules require minimal power and provide reliable delivery of data between devices. The interfaces provided with the module help to directly fit into many industrial applications. The modules operate within the 2.4-2.4835 GHz frequency band with IEEE 802.15.4 baseband. A feature of Zigbee is as follows:

Range - Indoor/Urban: up to 300 mts. Range - Outdoor line of sight: up to 50kms with directional antenna. Transmit Power: up to 1 watt / 30 dBm nominal. Receiver Sensitivity: up to 107 dBm. RF data rate: 250 kbps. AT Command Modes for configuring Module Parameters Direct sequence spread spectrum technology. Analog to digital conversion and digital I/O line support. Tarang can be interfaced with a micro controller or a PC using serial port with the help of appropriate level conversion.

Fig2.6.1 Interfacing ZigBee Module

Specification of the Tarang is given in the following table 2.3:

General

Operating FrequencyISM 2.4 GHz

Indoor/Urban rangeUp to 100ml with 2db antennas

Transmit Power output19dbm Typical

RF data rate250 Kbps

Antenna OptionsMMCX Connector, Chip Antenna, Wire Antenna

Table2.4 Specification of the Tarang

Power

Supply Voltage (vcc)3.3 to 3.6v

Transmit Current120mA

Idle/receive Current65mA

Power-down