Linked Questions

2
votes
4answers
5k views

How to use Multiple MPU9250 to Arduino Lilypad [duplicate]

Is it possible to connect more than one or to be specific 5 MPU9250 into 1 Arduino lilypad? How will I set the addresses, and where should I put the pins for SDA and SCL? I hope someone out there ...
1
vote
3answers
806 views

SPI Wiring Confusion

I am currently trying to learn about SPI and how it works on the Arduino. I want to wire a MAX7219 chip to it to drive an 8x8 LED matrix with. Normally, I would assume the wiring from Arduino to ...
0
votes
3answers
338 views

Can Serial be safely used in an SPI interrupt routine

I have anecdotal experience that using Serial.print inside a slave's SPI interrupt routine (ISR) causes issues with transmission. It also seems that interrupts may be called more than once before the ...
0
votes
3answers
570 views

How to drive SPI MAX7219 7-segment led module using MCP23S17 extender

I have used Nick Gammon's (MAX7219) and (bitBangedSPI) libraries to drive SPI 7-segment 8 digit led modules successfully from the Arduino Uno. I would like to extend the number of Slave Select (CS) ...
0
votes
3answers
744 views

Long Distance Shift Register

I am using a Mega to control some relay boards. I have a 16 relay board near the mega, and I want to put an 8 relay board about 40 ft. away. So I figured I could use a shift register - instead of ...
3
votes
2answers
2k views

Weird output from chained 74HC595 shift registers

EDIT 4/2/18: The Arduino tutorial schematics have been corrected! See https://github.com/arduino/Arduino/issues/6433 for that issue. I have a project where I am trying to load a 16-bit number onto an ...
2
votes
2answers
82 views

Looking for learning resources to teach the “principles” rather than “follow this” projects [closed]

I just got the Arduino starter kit as my background is software developer (C++, python, etc) and I'm interested to get into the electronics side, and I love LED effects and home automation of all ...
1
vote
2answers
166 views

Looking for SPI documentation

I'm trying to use an Arduino as a slave and was searching for examples which I found many. But apart from the examples, I haven't found any documentation explaining many thing that show up in those ...
1
vote
2answers
1k views

MISO pin issue in SPI

I have interfaced sd card and ADS1262 (ADC module) with Arduino mega board and sharing the SPI control pin i.e. SCK, MISO and MOSI. I have found that sd card is not initialized and ADS1262 is giving ...
0
votes
2answers
901 views

Is Arduino uno SPI comunication can be also master and slave in the same time?

Is Arduino uno SPI comunication can be also master and slave in the same time? OR master 2 slaves in the same time? I want to recevice data from a sensor and display on OLED (all data transfer with ...
-1
votes
2answers
304 views

which spi mode shall i use given this timing diagram

I need some help to ensure my understanding of how this is supposed to work. I want to know given the attached serial timing diagram which spi mode should I use? Based on my newly found knowledge I ...
1
vote
1answer
833 views

Sharing a Digital Pin / What to do when two components need a specific Digital Pin?

I am new to the world of Arduino and picked up an Uno R3. I have run into a situation where I have two components that specifically need digital pin 11, 12, 13 as specified by the libraries used to ...
0
votes
1answer
48 views

SPI transactions in Arduino

I have a task where I should do SPI transactions in interrupt mode. Means I have to handle data in IRQ handler (both for tx and rx bytes). How should I approach? I have a arduino board (2560) and a ...
0
votes
1answer
2k views

Multiple Slaves(Arduino Mega 2560) response over SPI

I have problem creating Setup which have : A SPI Master (Arduino Mega 2560) SPI slaves (Arduino Mega 2560) ,which responds to the Masters request by sending float data (or Rather a 2D float array ,...
0
votes
1answer
613 views

Using SPI Interrupt causes two servos to lose functionality

My Arduino MEGA clone (ATMEGA 2650) reads SPI data as a slave using an interrupt. There are also two servos that make an arm (shoulder and elbow). When I comment out the line that attaches the SPI ...