You have a Mega2560, therefore it has an ATmega2560 microcontroller, selected by default as processor. Im trying to use the external interrupts on pins 20 and 21 (SDA and SCL), and Im noticing that theres some unpredictable behavior that doesnt seem to be officially documented anywhere. Select your board type and port You'll need to select the entry in the Tools > Board menu that corresponds to your Arduino board. Arduino Mega, SDA/SCL pins, and interrupts. They don't appear to be labled on the added pins next to AREF, so picking the wrong one on this attempt is 50/50. Open the LED blink example sketch: File > Examples >01.Basics > Blink. Can any harm arise from accidentally swapping the SDA for the SCL? I'm thinking no, as its just a zero to 5 volt square wave on either. The Customer must not rely on the absence or characteristics of any features or instructions marked 'reserved' or 'undefined. It all works so slick and easy like everything else with the Duemilanove, just not with the Mega 2560 R3.įor fun, I am going to try the other two SDA and SCL pins. Arduino may make changes to specifications and product descriptions at any time, without notice. I checked the output on the Mega's I2C pins with an oscilloscope, and there is certainly a 0 to 5v signal coming out of both SCL and SDA on the Mega. I've tried a variety of values of pull up resistors, and also no pull ups, and still get no I2C function on the Mega. I have another Mega on order, and perhaps it will be the same, or it might work. When I run any of 3 I2C scanners on my Mega, nothing shows up for the I2C devices. I now know that the devices, a compass and lcd work perfectly with my Duemilanove. When you use SPI on the UNO it always uses pins 11-13 (MOSI, MISO and SCK in that order). I've been struggling with an otherwise excellent Mega 2560 R3, that for some reason doesn't communicate with any I2C device. On small MCUs like the Arduino uses these functions are fixed in hardware (more advanced MCUs employ a system to allow you to map the functions to different pins). This is not recommended because you bypass the LD1117S50CTR 5V voltage regulator and have to make sure that the voltage level is stable.Thanks all. You can also power power the Arduino microcontroller from the 5V pin. You cannot power the board with the barrel jack and VIN GPIO at the same time, because there is a polarity protection diode, connecting between the positive of the barrel jack to the VIN pin, rated at 1A. Therefore you are able to power the Uno with an external 9 Volt battery. The voltage has to be between 7V and 12V. VIN Pin: If you use an external power supply like a battery, you can use the VIN pin.If you buy a DC power jack, make sure the power adapter of the plug supplies a voltage between 7V and 12V. I connected a 1602 display to my Mega using the wiring in the posted code and ran the code. 5 Connector Pinouts 5.1 Analog 5.2 Digital 5.3 ATMEGA16U2 JP5 5.4 ATMEGA16U2 ICSP1 5.5 Digital Pins D22 - D53 LHS 5.
DC Power Jack: It is possible to use the DC power Jack as power supply. arduino mega 2560 - Pinout for LCD is not working. Arduino® MEGA 2560 Rev3 1 / 17 Arduino® MEGA 2560 Rev3 Modied: Product Reference Manual SKU: A000067.The standard USB connection delivers 5V and allows you to draw 500mA in total. USB cable: The most popular and also the easiest way to power the microcontroller is via USB cable.Like the Arduino Uno, you can power your Arduino Mega in three save ways because a voltage regulator provides a regulated and stable voltage for the ATmega2560 microprocessor: In my opinion you should be save to draw a current up to 100mA. The LP2985-33DBVR has a maximum output current of 150mA but on the official Arduino website, the maximum current is limited to 50mA. The maximum current draw from the USB connection is therefore reduced to 500mA.īecause the Arduino Mega has 3.3V pins to supply external electrical devices, there is a second voltage regulator build in, that reduces the voltage from 5V to 3.3V. Arduino Mega Pinout Arduino Mega Pin Diagram Controller Pins: RESET: (Reset input) A low level on this pin for longer than the 4 clock cycle will generate a reset. There is no need for a voltage regulator because the USB connection is already regulated by the USB output from your PC or laptop. The Arduino Mega can also be powered via the USB port. The maximum output current of the LD1117S50CTR is 800mA. Besides a higher input voltage than 12V has no advantage. But an input voltage between 7V and 12V is recommended to use the Arduino Mega over an extended period of time because otherwise the voltage regulator produces a lot of heat that can damage the microcontroller. The LD1117S50CTR provides a stable 5V output for the ATmega2560 and has a maximum input voltage of 15V.