![]() 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. ![]() 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. 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. 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. I've been struggling with an otherwise excellent Mega 2560 R3, that for some reason doesn't communicate with any I2C device. Serial.println("start") // to check functioning of Serial Monitor Serial.begin (9600) // start Serial Monitor with 9600baud I2c.beginTransmission(62) // write to decice with I2C-address dec 62 SoftI2CMaster i2c = SoftI2CMaster(sdaPin,sclPin) // define i2c Int16_t dac1_inc = 0 // signed 16bit variable for DAC-1 setting increments (0-4095) Test application for SoftI2CMaster library () Hoping that my error strikes your eyes, I would appreciate your comment. However, my compiler (Arduino IDE 1.6.5) keeps saying I wrote a tiny assembly sketch (included in full hereafter) to verify proper library usage. The Mega 2560 is based on AVR RISC Architecture. As this chip only allows selection of I2C-addresses 62 or 63 I need either a Hardware MUX or your smart piece of software. The Pinout of Arduino Mega is shown below: The description of pins present on the Arduino board are listed below: ATmega2560 Microcontroller - The Atmega2560 is a CMOS (Complementary Metal Oxide Semiconductor) low powered 8-bit microcontroller. I try to connect – by using your SoftI2CMaster library – more than two MCP4725 12-Bit DAC’s to an Arduino Nano (ATmega328). Hàm c s dng là wire.begin bt u chuyn i I2C, vi wire. Chân I2C: Chân 20 cho SDA và 21 cho SCK (Tc 400khz) cho phép liên lc hai dây vi các thit b khác. Thanks for letting me benefit from your work, Gii thiu Arduino Mega 2560 Trc ht, ti sao ti sao chúng ta nên la chn Arduino Mega 2560. must define "i2c" before including BlinkM_funcs_soft.hįor( int i=0 i< 100 i++ ) Ĭan you tell me if I am forgetting something? Can this even be done? const byte sdaPin = 7 // digital pin 7 wired to 'd' on BlinkMĬonst byte sclPin = 6 // digital pin 6 wired to 'c' on BlinkM The entirely of BlinkMSoftI2CDemo is shown below. It’s called “ BlinkMSoftI2CDemo” and shows off a simplified BlinkM_funcs called “ BlinkM_funcs_soft.h“. There is a simple demo for BlinkMs that this library currently lives in. I2c.beginTransmission( 9 ) // write to address 9 SoftI2CMaster i2c = SoftI2CMaster( sdaPin,sclPin ) In use it looks something like this: #include "SoftI2CMaster.h" write(data) - send some data (byte or byte arrays).beginTransmission(address) - begin sending data The Arduino Mega 2560 is a microcontroller board based on the ATmega2560.SoftI2CMaster(sdaPin,sclPin) - create an new SoftI2CMaster for the two pins specified Arduino Mega 2560 Rev3 Features The main features of Arduino Mega 2560 Rev3 are described below.The SoftI2CMaster API follows Wire’s API pretty closely: I’ve found using 2.2k resistors to be good. 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. Of course, you still need pull-up resistors on the two lines. If you dont use A4 and A5, they will stay high. Perhaps even with a prototype shield in between your shield and the Arduino 2560 board. You could connect the A4 and A5 to the real I2C pins. Here is a list of those libraries: Arduino I2C libraries For the SoftI2CMaster library, I wanted it to be very tolerant, even lazy, about bus problems and also have more tunable timing to let you slow the bus down. You could try a software I2C library on pin A4 and A5. If there is any noise or other bus problems, the Wire library will currently lock up. This is because the Wire library assumes a perfect bus. Because the I2C cable was longer than a few feet, the normal Wire library that BlinkM_funcs.h uses to communicate with BlinkMs couldn’t be used. It’s still a work in progress, but it can write data pretty successfully and do it over longer cables than normal.įor the VIMBY/Scion Hackerspace Challenge, I created an array of BlinkM MaxM-powered accent lights for the device we made. Ever wanted to use any pair of pins for I2C on Arduino, not just the dedicated pins on Analog 4 & 5? Me too, so I made a quick little Arduino library called “SoftI2CMaster”, available in the “blinkm-projects” Googlecode repository.
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