These pins are D8 to D13 (excluding crystal pins) in Arduino pin mapping. When PCIE0 (bit 0) is set, then the PCINT pins 0 to 7 are enabled. If you are lucky enough to have a Seeeduino Mega, you can make the Video Experimenter work with it by connecting a few jumper wires. To enable pin change interrupt on a pin, we’ll need to manipulate the PCICR register: The last three bits of this register are control bits for enabling a PCINT group. The ATmega1280 and ATmega2560 have four pins that have this feature, but none of them are connected to Arduino headers! Evidentally, the designers of the Arduino Mega did not think anyone would be interested in using the input capture feature of the ATmega microcontrollers. Evidently, the designers of the Arduino Mega did not think anyone would be interested in comparing analog voltages.Īlso, overlaying text and graphics on a video image requires the use of an input capture pin so that we can know precisely when the beginning of a video line begins. The analog comparator pin AIN0 on the ATmega1280/ATmega2560 is not connected to any Arduino Mega pin! This is pin 4 on the ATmega1280/ATmega2560 and as you can see in the schematic, it is not connected. These features are connected to different pins on the Arduino Mega or not connected at all. The Video Experimenter depends on ATmega features like input capture, external interrupt detection, and the analog comparator. These interrupts are mapped to digital input pins. However, I cannot use the given pins by the encoder (31/33) with these PCINs, means I have to find a solution to poll them somehow.Many of the pin assignments on the Arduino Mega are different than the pin assignments on the Arduino Uno/Duemilanove/Diecimila. The MEGA 2560 supports up to six external interrupts that are readily accessible to end user developers. Not sure why it does not work with Y_MIN_PIN (14) since it is PCINT10, I did try it again, but without success. It looks as if the library does not support to use INT7:0, this is the reason why it did not work with with X_MIN_PIN (3). Thanks to all of you for all your help to improve my understanding how these pin change interrupts work. Pin 10 is assigned to heaters and fans mosfet on the RAMPS 1.4 so I cannot use it, but I tried it with the pin A9 and it worked fine there. Now I understand that PCINT23:0 means a range of pins from PCINT0 to PCINT23, but it covers not all the pins on the ATmega2560.īTW, there is a document which explains the megaAVR interrups in general pretty good. and that they're different than "pin change interrupts", which work on all (or nearly all) of the pins. I picked that up there, but it did not notice that it was probably meant for a Atmega328 and not all ports of the ATmega2560 are covered by PCINTs. Hello I am in the process of making an RC craft, and have successfully used a Mega 2560, with pins 2 and 3 for interrupts. "The External Interrupts are triggered by the INT7:0 pin or any of the PCINT23:0 pins" The beeper (led) works fine if I uncomment the line in the loop code.Īny idea what could cause this issue that the interrupt does not work? External Interrupts: 2 (interrupt 0), 3 (interrupt 1), 18. I have tried the ports X_MIN_PIN (INT5), Y_MIN_PIN and BTN_ENC, but none of these work. Pins 0 and 1 are also connected to the corresponding pins of the ATmega8U2 USB-to-TTL Serial chip. This is my test code (slightly modified sample code) for the library which does not work for some reason: #include There are pin mappings to Atmega8 and Atmega 168/328 as well. Below is the pin mapping for the Atmega2560. For example, if you connect to pin 3, use digitalPinToInterrupt (3) as the first parameter to attachInterrupt (). Normally you should use digitalPinToInterrupt (pin) to translate the actual digital pin to the specific interrupt number. On MEGA, you can only do LOW, not FALLING or RISING. A diagram showing the correspondence between the pins on an Arduino board and those of the ATmega2560 microcontroller. The first parameter to attachInterrupt () is an interrupt number. But if you couple I see right away On UNO, you can wake it with LOW, FALLING, or RISING of external interrupt 0 and 1. Tracing that problem back I found out, that it seems the problem comes from PCINT library which does not trigger the interrupt. Here is an example where it fails and creates confusions: On MEGA2560, Arduino external interrupt 0 and 1 are on pins are 2 and 3, just like on UNO. I actually wanted to create an LCD menu which get controlled by the encoder, but then I noticed that the encoder did not work. My used hardwarea is an Arduino Mega with a RAMPS 1.4 shield and a RepRap Discount SmartController LCD including an encoder and button. I did try to run a simple sample code from the Pin Change Interrupt Library (PCINT) library, but for some reason it did not trigger the interrupt.
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