Questions tagged [spi]

Serial Peripheral Interface. Allows full-duplex serial communication from a master device to one or more slave devices arranged on a bus. Sometimes referred to as a 4-wire bus.

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Why is my SPI clock voltage lower at higher frequencies?

I measured that the SPI-Clock of my Arduino Nano in my project didn't reach near 5V. So I quickly tested with a new one, nothing attached except a (mydaq) scope. I measured the SPI clock: 2.5 V @ 8 ...
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ESP32: spi_master: check_trans_valid(801) when using SPI

I use the following code to communicate with a display: void Display_HandleDC(spi_transaction_t* p_Transaction) { gpio_set_level((gpio_num_t)LCD_DC, (uint32_t)p_Transaction->user); } static ...
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RFM69 Sending Failure

Hi I'm trying to get the RFM69 rf module to work on an arduino uno. Here is my code: #include <SPI.h> // Addresses for this node. CHANGE THESE FOR EACH NODE! #define NETWORKID 0 // Must be ...
Aaron's user avatar
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Rfid Mfrc522 not working using long cable

I am doing a project using Arduino and a Rfid Mfrc522 module that consists of reading a card to unlock/lock a door. The Arduino is 3 meters far away from the Rfid Mfrc522 module and I used 7 cables to ...
Enzo's user avatar
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Arduino uno spi sck not working

I am trying to verify sck output on my arduino uno. I don't have oscilloscope so I loopbacked miso to sck and tried Executing int rx0=SPI.transfer(5) while printing this using Serial.printrx0) it is ...
manish kumar's user avatar
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Store files in AT45DB161D SPI chip to use them from arduino

I am new to this concept but I am wondering if it is possible to store some files on the AT45DB161D dataflash chip. these files must be read by Arduino. I know that I should use a file system and I ...
Yasin's user avatar
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Correct usage of SPI with ISR

My Arduino needs to do: Run ISR as many times as possible/ as fast as possible. Occasionally receive data over I2C. Output data over SPI in ISR. My question is regarding SPI and ISR. The ...
aWiseMan's user avatar
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How to change the default SPI pin used in SPI and Ethernet library [duplicate]

Hello i have a custom board of the RP2040 and would like to use the ethernet library. But the ethernet example webClient uses the default SPI pins of whatever board it is being used, but what if im ...
DrakeJest's user avatar
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SPI problem with Bitcraze PMW3901 sensors and Arduino NANO

I am currently trying to connect four Bitcraze PMW3901 sensors to an Arduino NANO, but I seem to have issues with the SPI. When I connect two sensors using the code below, it works perfectly: I am ...
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ESP32 cam module SPI and NRF

I'm trying to use nrf2401 as transmitter on ESP32-cam module. I'm programming with Arduino IDE, but I'm not sure how to set the pins. I know that the board has 2 SPI interfaces. The first one is for ...
Simeon Baltadziev's user avatar
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Stand alone Atmega328p-au

I'm trying to make a standalone arduino board with an OLED display using an Atmega328p. I never tried to make such a board using SMD components. I've soldered everything together except the OLED ...
Aerandir's user avatar
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ADC stops working at small delays (MCP3464)

I have tried debugging for a couple days with no luck, so this question is a cry for help. I am trying to configure an external ADC (MCP3464 datasheet). The ADC uses SPI communication and I am getting ...
Will Powell's user avatar
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RaspberryPi Pico SPI and nrf24l01

I am programming a RaspberryPi Pico with the Arduino IDE. Works pretty well, but now I try to control an nrf24l01 module. My code compiles but I do not know on which pins the SPI bus has to be hocked ...
qubit's user avatar
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ESP32 WROOM32 SPI EMF issues

I'm trying to run Waveshare SSD1327 128x128 screen via SPI on ESP32 WROOM32 board. On ESP8266 (D1R1?) it works flawlessly while using HW SPI but when I run it on esp32, anything connected to mains ...
user1726744's user avatar
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Trying to use I2C accelerometer and SPI OLED

I'm trying to stream the data coming from my I2C MMA8452Q accelerometer to an Adafruit-based SSD1351 OLED RGB display that uses SPI via an Arduino UNO. When I run example code for the accelerometer I ...
Tom W's user avatar
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How can the SAMD21 chip knows when the on-board NINA W102 restarts

I am building a project that requires the SAMD21 microcontroller to send a resetToFactory signal to the NINA W102 on Arduino Nano 33 IoT. My plan is that, once the W102 receives the signal will do NVS ...
Lu Chih Yuan's user avatar
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MAX31865 and PT100 readings problem

PT100 (3 wire) is connected to arduino uno as i believe i have them connected properly, i have checked other forums such as changing the capacitor to ferrite core, and probably changing up to 4 ...
Lactobacillus's user avatar
2 votes
1 answer
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SPI.begin doesn't work after tristate

I am working on a ultra-low power project using an ATMEGA328P, a nRF24L01 and a 0.47F super-capacitor to measure various sensors akin to Gammon's solar power project. I have been having problems with ...
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SPI synchronization with Arduino DUE and ADIS16364 IMU

I'm trying to use an Arduino Due to interface with an ADIS16364 IMU from Analog Devices (product info here) via SPI. There are two modes for retrieving the measurements from this particular IMU (six ...
Guillermo Benito's user avatar
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Reading a flash ROM chip (M45PE20) through SPI with an ATMEGA 2560 -- output only FF's

I'm trying to communicate through SPI to a Flash ROM chip (M45PE20) with an ATMEGA 2560. I'm looking to read the data off the chip, but the output I'm getting is nothing but FF's. I've checked my ...
CaesiumWhale's user avatar
2 votes
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282 views

Using ICSP pins as SPI in Arduino Due

I am using two RFID sensors operating on SPI with arduino Due. They will not be operating at the same time. Is it favorable to use the ICSP pins as SPI pins for one of them, or use them in a one ...
sarah 's user avatar
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Reading and writing to GD25B32CPIG flash memory

I recently removed a GD25B32CPIG flash memory chip from a commercial coin-operated arcade game. Apparently it has all the game's sounds stored directly on the chip. I decided to see if I can learn to ...
Ben Stafford's user avatar
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1 answer
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Arduino does not boot when SPI lines are loaded

i connected an Arduino Nano to an external SPI Flash using THIS tutorial (russian) and the SPIMemory library. While accessing the Flash works well, i have encountered the following issue: The Problem: ...
Sabulanis's user avatar
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1 answer
516 views

Sending multiple data with SPI interface monitored by an Osciloscope

I have multiple 32-bit data stored in an array, and I want to sequentially send them by SPI interface. I want to check that my code is correctly sending data by SPI interface, so I upload the code and ...
jcwu's user avatar
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Converting ESP32 SPI code to Arduino for MAX6921 IV-18 driver board

I purchased a IV-18 VFD tube driver module, which came with some example code for an ESP32 board. The driver module has a 20 output MAX6921 serial chip to drive the vacuum tube. I want to use this ...
Alexander Holsgrove's user avatar
1 vote
1 answer
131 views

Interfacing SPI (MCP3903)

I'm trying to interface MCP3903. I haven't really don't any SPI interfacing before and I can't seem to find clear enough answer for newbs. Please bare with me. I'm trying to use this library. http://...
tryingengineer's user avatar
2 votes
0 answers
110 views

SPI Arduino slave not recieving data correctly

Using an STM32L476RG Nucleo microcontroller board as the SPI master and an Arduino mega as a slave with pin 52 for SCLK, pin 53 for SS and pin 51 for MOSI on the Arduino. There is no issue with the ...
Osz's user avatar
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Arduino recieve sensor data from other arduino SPI

I have Arduino Uno (sender) and Arduino Uno Wifi rev 2 (receiver). I want to send the ping value to the other one via serial - jumper wires. Arduino Uno is using the newping example, and I want the ...
foxtrot22's user avatar
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WDT ISR not called when SPI ST7789 module initiated

Using the .init function for the ST7789 TFT screen prevents my WDT ISR from firing. What explains this behaviour, and is there something I can do? Any other timer ISR I could use instead? #include <...
JCSB's user avatar
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2 votes
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nRF24L01 +pa +lna link does not communicate

I’m trying to create a link between two nRF24L01 units. Each nRF24L01+-based module (purchased) is connected to Arduino Nano on a custom-designed PCB. The printed wiring is per the hardware ...
user1511360's user avatar
1 vote
0 answers
62 views

Raspberry Pi with multiple arduinos using spi

I want to use Raspberry Pi as an aggregator & distributor of messages originating from or destined for a flight simulation program. I'd like to use arduinos connected via spi as specific hardware ...
Patrick Callahan's user avatar
1 vote
1 answer
326 views

SPI read while writing?

I'm working on a driver for an SPI device that returns some data (device status) while the command byte is still being written. Is there a way to read this status data using standard Arduino APIs or ...
Alex Hajnal's user avatar
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1 answer
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Is it possible to write data to a fat file system on SPI flash using an arduino?

I have an SPI flash based mp3 module and was wondering whether its possible to write to the flash chip using a microcontroller(arduino). the IC supports FAT16/FAT32 file systems. I have researched ...
user2105725's user avatar
1 vote
0 answers
248 views

Arduino Master SPI MISO Receive Data

I'm trying to interface an Arduino Mega with an AD7714 ADC. This ADC requires a command to be sent to the communications register (in my case 0x5C) in order to begin a read from the data register. My ...
Gruissan101's user avatar
3 votes
0 answers
156 views

Black screen when using higher SPI-speed for RA8857 LCD-controller

I'm using an Arduino Due that talks via SPI to an LCD (800x480) with the RA8875 controller chip. The most recent datasheet I could find is: RA8875 datasheet. Everything works as expected when using ...
Sven Onderbeke's user avatar
1 vote
1 answer
533 views

25Q128 flash and garbage data over SPI

I have a logic analyzer coming in the mail, but thought I might ask for help here first. I soldered the 25Q128 flash onto an adapter and wired it up to an Arduino UNO clone as you can see in the ...
atx's user avatar
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'class Adafruit_SPIDevice' has no member named 'endTransaction'

So what I have done is followed all of the instructions in the following link: https://learn.adafruit.com/adafruit-pygamer/setup and have managed to get all the way up to https://learn.adafruit.com/...
DigitalRookie4's user avatar
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Getting Trouble in multiple ST7789 SPI LCDs (without CS) with ESP32

I am developing a product in which i have to use 5 LCDs. The LCD i am using does not contain CS pin. SO i had to use MUX for muxing of complete SPI bus from one LCD to other. But the issue i am facing ...
faiz07's user avatar
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2 votes
1 answer
271 views

Updating SPI transfer16 to create Transfer24

It might be a bit out there, but for a project that I am working on, my word size default is 24bits (3x8-bit), of which the first 8-bits are data and the next 16-bits are data. I would like to ...
sandeepzgk's user avatar
2 votes
1 answer
471 views

seeeduino can-bus shield v2: can't read can bus and write on SD card

I'm using a seeeduino V4.0 and a CAN-BUS shield v2.0 with industrial grade SD card. I'm using the default library given by the wiki of seeed. I've simulate a can bus with two mcp2515. I can read it ...
Thanatheos's user avatar
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Is it possible for Arduino as ISP board to flash an ISP master board?

I have a setup of 2 Arduino Leonardo boards. Let's refer to them as Board A and Board B. Board A is a master SPI board that is constantly communicating via SPI to an array of sensors. At some point, ...
SomeGuy's user avatar
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Max. external ADC speed with ESP32 (SPI or I2C)?

What is the maximum speed for external ADC I can expect to get with ESP32? I'm planning to have 16-bit ADC connected to I2C or SPI whichever gives more speed. How that information is calculated from ...
tipo1000's user avatar
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1 answer
388 views

How to set SPI speed for ATmega1284P?

I am using MightyCore and platformio. My config file looks like this My fuses are set as: E:FD H:D6 L:8F I have controller running at 16 MHz and SCK frequency is 8 MHz. My display is showing white ...
zoonman's user avatar
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1 answer
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Multiple peripherals using SPI with a Mega

I am using a Mega 2560 and 2 x AD9833 programmable waveform generators. The AD9833's use a SPI protocol and I have used vwlowen's code as a jumping off point (I'm not usng the display just the ...
DrBwts's user avatar
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nRF24l01+ Problems. Data is being recieved as 0

I am trying to transmit the values of three potentiometers via the nRF24L01+ (w/antenna). I am using the regulator designed for the nRF24L01+, so I don't think I need to add a decoupling capacitor. I ...
Robert Spiers's user avatar
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0 answers
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SPI Clock Signal not stable

I am probing the SPI Clock pin 13 with my analog discovery 2. Nothing else is connected. The clock signal is there but it rises over time. (see picture) Here is my code: #include <SPI.h> void ...
user1441016's user avatar
4 votes
1 answer
325 views

SPI between Master arduino and Slave arduino

How can I send the string from Slave SPI to Master SPI? I want to write code in Bare Metal. The problem which I am facing is I can't make out what will be my blocking function in Master SPI code when ...
Kunal's user avatar
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1 vote
3 answers
851 views

Is it necessary to set a function with always_inline attribution when the function would work maybe once?

I'm going through a library for the ILI9488 running by SPI and want to copy this library in my version. In the beginning of the source file, there's a guard for the SPI_HAS_TRANSACTION that if the ...
R1S8K's user avatar
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6 votes
3 answers
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When is SPI.beginTransaction required?

I have been gradually converting many devices from i2c to spi for various reasons. I noticed in tutorials like this from arduino.cc that SPI.beginTransaction is explicitly called out. Then they link ...
Matt's user avatar
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2 votes
1 answer
447 views

What are a few good ways to connect multiple I2C busses?

I have an issue with a project. I have a backplane with an Atmega328P based microcontroller controlling an I2C bus with multiple peripheral devices. One such peripheral is a removable card with ...
Delaney Fitzpatrick's user avatar

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