Basic Circuit

Honeywell SC8105-001 IR Photodarlington Transistor

Published:2013/10/24 20:12:00 Author:lynne | Keyword: Photodarlington Transistor

Honeywell SC8105-001 Features & Specs Low cost Popular T-1 plastic package Opaque black visible light filter to exclude visible light High sensitivity Acceptance angle: ±10o Wavelength: 935nm peak (Infrared spectrum) Light current: 500µA Min Dark current: 0.25µA Max   (View)

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GFI Ground Fault Interrupter Wall Wart

Published:2013/10/23 20:28:00 Author:lynne | Keyword: GFI Ground Fault Interrupter Wall Wart

I always wondered what was inside one of these clever devices, so I found one in my junk box and popped the lid—it was from a defunct blow hair dryer—never throw one of these away because the GFI unit long outlives the hair dryer and has many experimental uses. To get it apart, I had to make a special screw driver bit to remove the tamper resistant screws. Inside was something that resembles a relay, a circuit board and a tiny current transformer. This did not happen by itself—that is why I cannot accept the theory of evolution—there was a designer! The contacts resemble those of a relay, but are actuated manually via a button that protrudes through the cover, and released via a small solenoid operated plunger. There is a test pushbutton that operates a crude leaf contact on the small circuit board. I traced out the circuit carefully and drew up the schematic. The IC is probably a variant of the Fairchild RV4141A or RV4145A because the pin out does not exactly agree with either device. Regardless, there are numerous ways of applying IC’s and the schematic in the application note is merely a guide. The current transformer is very likely a 1:1000 turns ratio device. Ground Fault Interrupter Schematic How it works You will notice that the parallel power leads make a single turn through the primary of the current transformer (CT). The flux field of the source lead is cancelled by the flux field in the return lead so the net result is zero and the CT sees no primary current. Should these currents ever become unequal (as in a ground fault condition), the CT senses this difference and induces current into the 1000 turn secondary. The secondary current is low, but the load resistance is 1M, so it develops significant voltage. This voltage is sufficient to exceed the comparator threshold voltage of the IC and fire the SCR. When the SCR fires, it energizes the solenoid coil and jerks an iron slug toward the center of the coil. Attached to this iron slug is a stainless steel pin that actuates the mechanical release for the electrical contacts. When the contacts are open, the ground fault current is interrupted and the appliance is off-line. It remains off until the mechanical reset button is pressed. Note that this is for an unbalanced fault condition in which the current flows to ground. It cannot provide protection for a balanced fault such as holding both ends of a suicide cord in either hand. C1 prevents any DC bias current from flowing through the CT secondary. It does not take much primary current to saturate the core and degrade its performance. RV1 is a MOV transient suppressor—this is required to pass the 5000V UL/CSA/VDE transient voltage test. There is also a small red wire that also goes through the CT opening—this is the test turn and it connects to a 15K resistor. When the test pushbutton is pressed, it connects the 15K resistor across the line and forces a low unbalanced current (7mA) through the primary. This low current simulates a limited ground fault condition that is similar to a mild electrical shock. Actual sensitivity is 4.8mA—I measured it by substituting various resistors. UL/CSA/VDE standards assume that anything below 5mA is non-life threatening. Preventing nuisance trips is a requirement. This is what the 6.8uf gate to cathode capacitor is all about—it swamps out noise pulses, but charges up to the SCR gate voltage threshold when there is a real ground fault signal present. Components to save for future experimentation Current Transformer Solenoid SCR   (View)

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Variable Power Supply with UA78G/UA79G

Published:2013/10/21 20:31:00 Author:lynne | Keyword: Variable Power Supply

A stable variable power supply with an adjustable output voltage from 5 volts to 30 volts can be easily constructed with the regulator ICs UA78G or UA79G. These ICs differ from the common three-terminal regulator since their output voltages are adjustable by a voltage level at their control inputs. The maximum current delivered by these ICs is 1 ampere. The unregulated voltage must be at least 5 volts higher than the desired output level to maintain stability. The input voltage however must not exceed 40 volts. The maximum dissipation of the IC is 15 watts. The variable power supply circuit presented here is designed to give maximum voltage level of 28 volts. If P1 is replaced with 25K potentiometer, the regulator can deliver up to a maximum of 30 volts. Capacitors C1 and C2 stabilize the IC and they must be connected as close as possible to the IC terminals. UA78G/UA79G power supply circuit diagram   (View)

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USB DC Power Supply from Cigar Lighter Socket

Published:2013/10/20 20:14:00 Author:lynne | Keyword: USB DC Power Supply from Cigar Lighter Socket

The diagram shows the circuit of a versatile USB power socket that safely converts the 12V battery voltage into stable 5V. This circuit makes it possible to power/recharge any USB power-operated device, using in-dash board cigar lighter socket of your car. The DC supply available from the cigar lighter socket is fed to an adjustable, three-pin regulator LM317L (IC1). Capacitor C1 buffers any disorder in the input supply. Resistors R1 and R2 regulate the output of IC1 to steady 5V, which is available at the ‘A’ type female USB socket. Red LED1 indicates the output status and zener diode ZD1 acts as a protector against high voltage. USB Power Socket Circuit Diagram Assemble the circuit on a general-purpose PCB and enclose in a slim plastic cabinet along with the indicator and USB socket. While wiring the USB outlet, ensure correct polarity of the supply. For interconnection between the cigar plug pin and the device, use a long coil cord as shown in Fig. 2. Pin configuration of LM317L is shown in Fig. 3.   (View)

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Cheap DC Voltage Doubler Circuit

Published:2013/10/20 20:12:00 Author:lynne | Keyword: Cheap DC Voltage Doubler Circuit

This is a cheap DC Voltage Doubler Circuit diagram, which requires a few components and will deliver 10V from a 5V power supply. If the oscillator must be built from a non-functional gate then is required 2 more components: R1 and C3.The most important parameters of this voltage doubler circuit are given in the table below. Note that because of the IC tolerances these data may have some differences. Voltage doubler circuit diagram   (View)

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Adjustable Voltage Regulator with TDA2030

Published:2013/10/16 20:16:00 Author:lynne | Keyword: Adjustable Voltage Regulator with TDA2030

This Adjustable Voltage Regulator is made by combining a common 78L05 with an integrated audio amplifier of the type TDA2030, an adjustable voltage regulator can be constructed in a very simple manner that works very well. The output voltage is adjustable up to 20 V, with a maximum current of 3 A. Since the TDA2030 comes complete with a good thermal and short-circuit protection circuit, this adjustable regulator is also very robust. As illustrated by the schematic, the design of this circuit is characterized by simplicity that is hard to beat. In addition to the two ICs, the regulator contains actually only two potentiometers and a few capacitors. The adjustment is done by first turning potentiometer P1 to maximum (wiper to the side of the 78L05) and subsequently turning trimpot P2 until the desired maximum output voltage is reached. P1 is then used to provide a continuously adjustable voltage between this maximum and nearly zero volts. At relatively small output currents there are no specific requirements regarding the cooling. However, when the output current exceeds 1 A, or if the input to output voltage difference is quite large, the amplifier IC has to dissipate too much power and a small heatsink is certainly appropriate. Variable Voltage Regulator Circuit Diagram   (View)

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TDA7294 Datasheet

Published:2013/10/16 20:13:00 Author:lynne | Keyword: TDA7294 Datasheet

The TDA7294 is a monolithic integrated circuit in Multiwatt15 package, intended for use as audio class AB amplifier in Hi-Fi field applications (Home Stereo, self powered loudspeakers, Topclass TV). Thanks to the wide voltage range and to the high out current capability it is able to supply the highest power into both 4Ω and 8Ω loads even in presence of poor supply regulation, with high Supply Voltage Rejection. The built in muting function with turn on delay simplifies the remote operation avoiding switching on-off noises. TDA7294 Features DMOS power stage very high operating voltage range high output power (up to 100W music power) muting/stand-by functions no switch on/off noise no boucherot cells very low distortion very low noise short circuit protection thermal shutdown   (View)

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LM3886 Datasheet

Published:2013/10/15 20:36:00 Author:lynne | Keyword: LM3886 Datasheet

The LM3886 is a high-performance audio power amplifier capable of delivering 68W of continuous average power to a 4Ω load and 38W into 8Ω with 0.1% THD+N from 20Hz–20kHz. The performance of the LM3886, utilizing its Self Peak Instantaneous Temperature ( SPiKe™) protection circuitry, puts it in a class above discrete and hybrid amplifiers by providing an inherently, dynamically protected Safe Operating Area (SOA). SPiKe protection means that these parts are completely safeguarded at the output against overvoltage, undervoltage, overloads, including shorts to the supplies, thermal runaway, and instantaneous temperature peaks. LM3886 Applications component stereo compact stereo self-powered speakers surround-sound amplifiers high-end stereo TVs   (View)

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TDA2822 Datasheet

Published:2013/10/15 20:29:00 Author:lynne | Keyword: TDA2822 Datasheet

The TDA2822 is a monolithic integrated circuit in 12+2+2 powerdip, intended for use as dual audio power amplifier in portable radios and TV sets.TDA2822 features supply voltage down to 3V low crossover distorsion low quiescent current bridge or stereo configuration   (View)

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12V DC to 120V AC Inverter Circuit

Published:2013/10/15 20:21:00 Author:lynne | Keyword: 12V DC to 120V AC Inverter Circuit

Here is a simple 12 volts DC to AC inverter circuit. This 120V AC power source is built with a simple 120V:24V or 110V:24V center-tapped control transformer and four additional component. This circuit outputs a clean 200-V pk-pk square wave at 60 Hz and can supply up to 20W. The circuit is self-starting and free-running.If Q1 is faster and has a higher gain than Q2 is will turn on first when you apply the input power and will hold Q2 off. Load current and transformer magnetizing current then flows in the upper half of the primary winding, and auto transformer action supplies the base drive until the transformer saturates.When that action occurs, Q1 loses its base drive. As it turns off, the transformer voltage reverse, turning Q2 on and repeating the cycle. The output frequency depends on the transformer iron and input voltage but not on the load. The frequency range between 50 to 60 Hz with a 60-Hz transformer and car battery or equivalent source. The output voltage depends on turns ratio and the difference between input voltage and transistor saturation voltage. For higher power, use larger transformers and transistors. This type of 12V inverter normally is used in radios, phonographs, hand tools, shavers and small fluorescent lamps. It will not work with reactive loads (motors) or loads with inrush currents, such as coffee pots, frying pans and heaters.   (View)

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Wide Frequency Range 555 VCO

Published:2013/10/14 20:02:00 Author:lynne | Keyword: Wide Frequency Range 555 VCO

The 555 frequency can be varied via adjusting the voltage at pin 5. However, the range and linearity of frequency adjustment is very limited. This is a way to greatly improve performance using the inverted 555 timer circuit that was previously posted. 555 VCO Schematic Current source Q2 is connected in the common base configuration. In this mode of operation, the collector current is a function of emitter current regardless of the collector voltage. In this way, it can perform a linear charge function upon C1. The emitter must be driven from a negative supply voltage. Frequency is scaled to 10V = 10kHZ via R5. Frequency range in this set-up is 180 to 10kHZ. Bias transistor Q3 is wired as a self-biasing transistor by connecting the base to the collector and feeding it a bias current via R4. Voltage drop is 0.6V. Originally, I had a 1N4148 diode and its voltage drop was 0.45V that added too much offset to the emitter of Q1. Ideally, the voltage drop across Q3 should equal Vbe of Q2. This is a compromise because they are matched only under the condition of Ie = (9V – 0.6V) /R4 = 84uA. The emitter current varies from about 3 to 303uA. Lowest low end offset would occur with both transistors matched and R4 increased to 3M—in that case, the hFE @ 3uA must >100—this looks practical, but would require a different transistor selection—I did not experiment with this option.   (View)

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Greenhouse Heater Temperature Control

Published:2013/10/14 19:59:00 Author:lynne | Keyword: Greenhouse Heater Temperature Control

Standard resistance heaters used for space heaters sometimes have thermostats, but these are not adjustable to the low temperature settings required for winter greens. Instead of purchasing a high end programmable temperature controller, I fabricated this greenhouse heater temperature control project circuit. It cycles an electric heater. It has been operating for two winters now with good results, and I just added the LEDs so I could tell from a distance if it was functioning. Temperature Control Circuit Schematic Key components are documented on the schematic – there is no bill of materials. Power supply Basic transformer isolated full-wave center-tapped configuration with LM7812 voltage regulator Temperature probe This is simply (4) 1N4148 diodes connected in series with a thermal anticipation resistor (R1) heat shrunk together at the end of a (3) wire signal cable—it is visible on some of the photos. The use of a thermal anticipation resistor is an old HVAC thermostat technique that adds negative feedback to the system by immediately heating the temperature sensing device slightly. It forces short cycles and prevents temperature overshoot. Because the amount of power to apply to the thermal anticipation resistor was unknown, I incorporated a power level pot (R6). I later determined that it works quite well at the maximum setting, so the pot is not required. Although the temperature measurement can be accomplished via a single diode, four diodes in series are used to get the signal “out of the mud.” The inexpensive LM324 op amp has a maximum input offset voltage of 7mV, so the higher level voltage signal helps to improve performance. The diodes are biased at approx 4mA via R2. Comparator U1C is connected as a voltage comparator with positive feedback via R5. Positive feedback prevents relay chatter. C3 is an input noise filter capacitor. As the temperature cools, the voltage drop across the probe diodes increases. When it reaches the set point, the output changes states and the positive feedback through R5 further increases the non-inverting input by 5mV to assure that it remains latched until the temperature increases and the voltage drops below the set point. Calibration In a previous circuit http://www.electroschematics.com/409/diode-electronic-thermometer/ we see that the temperature coefficient of silicon diodes is approx. -2mV /°C. (4) in series boosts it to -8mV /°C. I dropped the probe in ice water and measured the voltage—2.773V in my case. Then I calculated what the voltage would be at 4.4°C (40°F). Then I adjusted the voltage at the calibration pot R8 to get 2.738V—this is the set point. Proper operation was subsequently determined by placing the probe in and out of ice water to observe cycling of the relay. Relay driver Q1 is a simple NPN relay driver. For more information check out this post: http://www.electroschematics.com/7123/relay-driver-2/Quencharc RC-1 is connected across the relay contacts to reduce arcing. These are unreasonably expensive, so I recommend using a discrete resistor and capacitor. Polypropylene is the capacitor of choice—just make sure that it has sufficient AC voltage rating; LED Driver U1A is another comparator that drives the LEDs. Red indicates power ON and Green indicates OFF. Greenhouse specifications For a guide for estimating your power requirements, compare your greenhouse with the following: Dimensions: 8ft wide x 12ft long x 7ft high. North side is insulated by high density foam to minimize heat loss East and West ends have a double layer of plastic sheeting South side and top are single layer greenhouse plastic—UV resistant—long life Latitude is 40oN.   (View)

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Single Pushbutton Run-Stop Circuit

Published:2013/10/13 20:37:00 Author:lynne | Keyword: Single Pushbutton Run-Stop Circuit

There are solutions to this problem—mechanical (push On/push Off switch), electromagnetic (latching relay) and electronic (CMOS logic), but few (if any) good discrete electronic solutions. I have scoured the web, looking for such and have not found any decent circuits. One recent job required such and I had to resort to CMOS logic — I will be posting that one in the future. As a result, I have been racking my brain for the last few months and have finally come up with a really neat circuit. It is a little busy, having 19 components, but they are small, inexpensive and commonly available. What are the benefits of such a circuit? Good question — one may wonder what use this could be. Besides being compatible with any normally open pushbutton, it is a great way to add multiple pushbuttons to a system—all normally open pushbuttons are simply wired in parallel — any can start or stop the device. Also note that push-on/push-off switches are quite special and have a limited offering in regard to size, mechanics and aesthetics—they also have an unpleasant feel, in my estimation. Single Pushbutton Run-Stop Schematic How it works When the pushbutton is initially closed, it directly turns on the gate of Q1 via D2. Q1 turns on after a brief delay determined by the charge time of C1. Q1 then biases Q2 on, and Q2 seals in the pushbutton signal and C2 charges up to 12V via R8 and D2. When the pushbutton is closed again, the top side of C2 is grounded via the pushbutton action through D1. The lower side of C2 goes negative and dumps half of its charge into C3. The negative voltage on C3 turns on Q3 that is connected in the common collector configuration (emitter follower). The emitter of Q3 shorts the bias voltage of Q2 to common thus turning off Q1 (as soon as the pushbutton is released).   (View)

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MAX232 Circuit

Published:2013/10/10 20:06:00 Author:lynne | Keyword: MAX232 Circuit

The MAX232 datasheet specifies that the IC is a dual driver/receiver that includes a capacitive voltage generator to supply TIA/EIA-232-F voltage levels from a single 5-V supply. Each receiver converts TIA/EIA-232-F inputs to 5-V TTL/CMOS levels. These receivers have a typical threshold of 1.3 V, a typical hysteresis of 0.5 V, and can accept ±30-V inputs. Each driver converts TTL/CMOS input levels into TIA/EIA-232-F levels. MAX232 Applications/Uses Battery-Powered RS-232 Systems Interface Translation Low-Power Modems Multidrop RS-232 Networks Portable Computing MAX232 Features Meets or Exceeds TIA/EIA-232-F and ITU Recommendation V.28
Operates From a Single 5-V Power Supply With 1.0-
F Charge-Pump Capacitors
Operates Up To 120 kbit/s
Two Drivers and Two Receivers
±30-V Input Levels
Low Supply Current… 8 mA Typical
ESD Protection Exceeds JESD 22 − 2000-V Human-Body Model (A114-A) Upgrade With Improved ESD (15-kV HBM) and 0.1-
F Charge-Pump Capacitors is Available With the MAX202   (View)

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7447 pin configuration

Published:2013/10/9 19:56:00 Author:lynne | Keyword: 7447 pin configuration

According to the 7447 datasheet the 7446A and 7447A ICs feature active-low outputs designed for driving common-anode LEDs or incandescent indicators directly. All of the circuits have full ripple-blanking input/output controls and a lamp test input. Segment identification and resultant displays are shown on a following page. Display patterns for BCD input counts above nine are unique symbols to authenticate input conditions. All of the circuits incorporate automatic leading and/or trailing-edge, zero-blanking control (RBI and RBO). Lamp test (LT) of these devices may be performed at any time when the BI/RBO node is at a high logic level. All types contain an overriding blanking input (BI) which can be used to control the lamp intensity (by pulsing) or to inhibit the outputs. 7447 Datasheet Features All circuit types feature lamp intensity modulation capability Open-collector outputs drive indicators directly Lamp-test provision Leading/trailing zero suppression   (View)

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24V to 36V Battery Charger

Published:2013/10/9 19:55:00 Author:lynne | Keyword: 24V to 36V Battery Charger

This 24V to 36V linear battery charger is long overdue. While this is an old circuit technique, it is optimized for charging higher voltage lead-acid battery packs, and could be used on other types of batteries as well. By proper transformer selection, it can be optimized for either 24 or 36V. Note that actual float charge voltage requires 2.4V /cell or 28.8 & 43.2V @ full charge respectively.   (View)

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Arduino Uno Pinout

Published:2013/10/7 22:12:00 Author:lynne | Keyword: Arduino Uno Pinout

Input and Output Each of the 14 digital pins on the Arduino Uno can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms.In addition, some pins have specialized functions:Serial: pins 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data. These pins are connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip. External Interrupts: pins 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. PWM: 3, 5, 6, 9, 10, and 11. Provide 8-bit PWM output with the analogWrite() function. SPI: 10 (SS), 11 (MOSI), 12 (MISO), 13 (SCK). These pins support SPI communication using the SPI library. LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it’s off. The Uno has 6 analog inputs, labeled A0 through A5, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and the analogReference() function. Additionally, some pins have specialized functionality: TWI: A4 or SDA pin and A5 or SCL pin. Support TWI communication using the Wire library. There are a couple of other pins on the board: AREF. Reference voltage for the analog inputs. Used with analogReference(). Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.   (View)

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Arduino Leonardo Pinout

Published:2013/10/7 22:05:00 Author:lynne | Keyword: Arduino Leonardo Pinout

Input and Output Each of the 20 digital i/o pins on the Arduino Leonardo can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms.In addition, some pins have specialized functions:Serial: 0 (RX) and 1 (TX). Used to receive (RX) and transmit (TX) TTL serial data using the ATmega32U4 hardware serial capability. Note that on the Leonardo, the Serial class refers to USB (CDC) communication; for TTL serial on pins 0 and 1, use the Serial1 class. TWI: 2 (SDA) and 3 (SCL). Support TWI communication using the Wire library.External Interrupts: 2 and 3. These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. PWM: 3, 5, 6, 9, 10, 11, and 13. Provide 8-bit PWM output with the analogWrite() function. SPI: on the ICSP header. These pins support SPI communication using the SPI library. Note that the SPI pins are not connected to any of the digital I/O pins as they are on the Uno, They are only available on the ICSP connector. This means that if you have a shield that uses SPI, but does NOT have a 6-pin ICSP connector that connects to the Leonardo’s 6-pin ICSP header, the shield will not work. LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it’s off. Analog Inputs: A0-A5, A6 – A11 (on digital pins 4, 6, 8, 9, 10, and 12). The Leonardo has 12 analog inputs, labeled A0 through A11, all of which can also be used as digital i/o. Pins A0-A5 appear in the same locations as on the Uno; inputs A6-A11 are on digital i/o pins 4, 6, 8, 9, 10, and 12 respectively. Each analog input provide 10 bits of resolution (i.e. 1024 different values). By default the analog inputs measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and the analogReference() function. There are a couple of other pins on the board: AREF. Reference voltage for the analog inputs. Used with analogReference().Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.   (View)

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Arduino Due Pinout

Published:2013/10/7 22:04:00 Author:lynne | Keyword: Arduino Due Pinout

Input and Output Digital I/O: pins from 0 to 53 Each of the 54 digital pins on the Due can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 3.3 volts. Each pin can provide (source) a current of 3 mA or 15 mA, depending on the pin, or receive (sink) a current of 6 mA or 9 mA, depending on the pin. They also have an internal pull-up resistor (disconnected by default) of 100 KOhm.In addition, some pins have specialized functions:Serial: 0 (RX) and 1 (TX)Serial 1: 19 (RX) and 18 (TX)Serial 2: 17 (RX) and 16 (TX)Serial 3: 15 (RX) and 14 (TX) Used to receive (RX) and transmit (TX) TTL serial data (with 3.3 V level). Pins 0 and 1 are connected to the corresponding pins of the ATmega16U2 USB-to-TTL Serial chip. PWM: Pins 2 to 13 Provide 8-bit PWM output with the analogWrite() function. the resolution of the PWM can be changed with the analogWriteResolution() function. SPI: SPI header (ICSP header on other Arduino boards) These pins support SPI communication using the SPI library. The SPI pins are broken out on the central 6-pin header, which is physically compatible with the Uno, Leonardo and Mega2560. The SPI header can be used only to communicate with other SPI devices, not for programming the SAM3X with the In-Circuit-Serial-Programming technique. The SPI of the Due has also advanced features that can be used with the Extended SPI methods for Due. CAN: CANRX and CANTX These pins support the CAN communication protocol but are not not yet supported by Arduino APIs. “L” LED: 13 There is a built-in LED connected to digital pin 13. When the pin is HIGH, the LED is on, when the pin is LOW, it’s off. It is also possible to dim the LED because the digital pin 13 is also a PWM outuput. TWI 1: 20 (SDA) and 21 (SCL)TWI 2: SDA1 and SCL1. Support TWI communication using the Wire library. Analog Inputs: pins from A0 to A11 The Due has 12 analog inputs, each of which can provide 12 bits of resolution (i.e. 4096 different values). By default, the resolution of the readings is set at 10 bits, for compatibility with other Arduino boards. It is possible to change the resolution of the ADC with analogReadResolution(). The Due’s analog inputs pins measure from ground to a maximum value of 3.3V. Applying more then 3.3V on the Due’s pins will damage the SAM3X chip. The analogReference() function is ignored on the Due.The AREF pin is connected to the SAM3X analog reference pin through a resistor bridge. To use the AREF pin, resistor BR1 must be desoldered from the PCB. DAC1 and DAC2 These pins provides true analog outputs with 12-bits resolution (4096 levels) with the analogWrite() function. These pins can be used to create an audio output using the Audio library. Other pins on the board:AREF Reference voltage for the analog inputs. Used with analogReference(). Reset Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.   (View)

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Arduino Mega 2560 Pinout

Published:2013/9/29 20:01:00 Author:lynne | Keyword: Arduino Mega 2560 Pinout

Input and Output Each of the 54 digital pins on the Arduino 2560 Mega can be used as an input or output, using pinMode(), digitalWrite(), and digitalRead() functions. They operate at 5 volts. Each pin can provide or receive a maximum of 40 mA and has an internal pull-up resistor (disconnected by default) of 20-50 kOhms.In addition, some pins have specialized functions:Serial: 0 (RX) and 1 (TX);Serial 1: 19 (RX) and 18 (TX);Serial 2: 17 (RX) and 16 (TX);Serial 3: 15 (RX) and 14 (TX). Used to receive (RX) and transmit (TX) TTL serial data. Pins 0 and 1 are also connected to the corresponding pins of the ATmega16U2 USB-to-TTL Serial chip. External Interrupts: 2 (interrupt 0), 3 (interrupt 1), 18 (interrupt 5), 19 (interrupt 4), 20 (interrupt 3), and 21 (interrupt 2). These pins can be configured to trigger an interrupt on a low value, a rising or falling edge, or a change in value. See the attachInterrupt() function for details. PWM: 2 to 13 and 44 to 46. Provide 8-bit PWM output with the analogWrite() function.SPI: 50 (MISO), 51 (MOSI), 52 (SCK), 53 (SS). These pins support SPI communication using the SPI library. The SPI pins are also broken out on the ICSP header, which is physically compatible with the Uno, Duemilanove and Diecimila. LED: 13. There is a built-in LED connected to digital pin 13. When the pin is HIGH value, the LED is on, when the pin is LOW, it’s off. TWI: 20 (SDA) and 21 (SCL). Support TWI communication using the Wire library. Note that these pins are not in the same location as the TWI pins on the Duemilanove or Diecimila.The Mega2560 has 16 analog inputs, each of which provide 10 bits of resolution (i.e. 1024 different values). By default they measure from ground to 5 volts, though is it possible to change the upper end of their range using the AREF pin and analogReference() function. There are a couple of other pins on the board: AREF. Reference voltage for the analog inputs. Used with analogReference().Reset. Bring this line LOW to reset the microcontroller. Typically used to add a reset button to shields which block the one on the board.   (View)

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