Questions tagged [spi]

The SPI bus, Serial Peripheral Interface, is a synchronous serial communication interface for short distance communication, e.g. between components in an embedded system such as the Pi. Devices communicate in full duplex mode using a master-slave architecture with a single master. The master device (typically the Pi) initates all communications.

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282 views

How should I be connecting CE/CS pins of a SPI device to GPIO pins in userspace?

I am trying to avoid using the built-in CS/CE 0 and 1 pins that the system defaults to when using SPI communication so that I can expand out to as many as 10 devices in the future. The devices in ...
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Waveshare RS485 CAN hat over raspberry pi 3A+

So I have been at least trying to connect to the hat from the Pi, the following is my configuration: I follow the manual set in this link: https://www.waveshare.com/w/upload/2/29/RS485-CAN-HAT-user-...
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Can we implement a protocol other than spi on Raspberry Pi?

Pi supports SPI, I2C and UART by default. Can we implement any other protocol like MDIO into it? If yes, how do we do it?
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Does Raspberry Pi 4 Support Android Things?

I am trying to communicate with an MFRC522 device using my RPi 4B and the SPI interface. My application is written in Java and communicates under NetBeans with the RPi as a remote platform. The ...
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SPI Not working when chip select is connected to ground, works fine when connected to CE 0,1 or 2

I am working on MFRC522 sensors. However I need more than 3 SPI Devices. The 3 works fine except when I want to connect chip select to GPIO, It does not work. I tried a single spi device by connecting ...
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How can Rpi python read SPI ADNS3080 Optical Mouse Sensor's register values?

I am using ADNS3080 optical flow in raspberry pi 3. I set SPI connection between raspberry and ADNS3080 optical flow. I used spidev library for reading values in python. I want to read delta_x and ...
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157 views

Loopback SPI interface not working

I'm trying to do the loopback test for the SPI interface on my raspberrypi model 2 B V1.1, by following the intruction on this website : https://www.raspberrypi.org/documentation/hardware/raspberrypi/...
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37 views

Control SPI Wirelessly

I would like to control a WaveShare e-Ink display wirelessly. I have lots of experience working with this type of device over SPI using the GPIO boards and the WaveShare python libraries. I'd like to ...
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How do I hold SPI high value?

I'm using wiringPi spi library to communicate two raspberries. As the spi clks aren't synchronised, I don't read the high values, since they are only a pulse. Is there a way to hold the high value ...
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2k views

Get cheap ST7789 TFT display working through SPI (without CS pin)

I purchased a cheap Chinese ST7789 TFT (1.3in, 240x240) that is clearly identified as SPI compatible, tough it does NOT have a CS pin and also some of the pins seem weirdly named to me. I have been ...
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918 views

Continuous data acquisition from ADC at around 10 MSPS

I would like to continuously stream data from an ADC with 12 to 16 bit to a Raspberry 4 at around 10 MSPS. Since the Raspberry is not realtime, I'm assuming I need some sort of FIFO buffer as ...
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Raspbian - Custom SPI Bus similar to custom I2c Bus

I am currently using this line to put in a custom I2C Bus in my boot/config file: dtoverlay=i2c-gpio,bus=4,i2c_gpio_delay_us=1,i2c_gpio_sda=6,i2c_gpio_scl=0 However, I want to be able to set up a ...
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How should I connect ten "MFRC522-based RFID" readers using SPI to the Pi Zero W?

Using the MFRC522.py library and SimpleMFRC522 extension, I have been able to pass tag ID information as well as the text block; but only for one tag at a time. Diving deeper into the MFRC522 ...
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Rpi reading only zero output results from SPI 10-bit ADC MCP3008 problem

I am attempting to make a temperature monitor based on these links: 1. https://bitbucket.org/pschow/rpiadctherm/src/dbfe8101eeb4/basiclogmcp.py?at=master 2. https://www.paulschow.com/2013/08/...
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Enable up to 5 SPI on Raspberry Pi 4

I'm trying to enable all the SPI Ports on my raspberry pi 4 (as mentioned in the datasheet). I already enable the SPI interfaces over the raspi-config tool but that only gives me spi0.0 and spi0.1 ...
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raspberry pi 3 spi issue

I connected MOSI to MISO on Raspberry PI 3 Executed the below code: import time import sys import spidev spi = spidev.SpiDev() spi.open(0,0) print(spi.bits_per_word) print(spi.mode) print(spi....
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Can't read data from PN532 NFC reader over SPI

I'm using Pi4J library to read data from a NFC reader based on PN532, connected to my Pi via SPI. However, I don't seem to receive any data from if when I put a NFC card to my reader. I'm using SPI0 ...
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4k views

How to detect if an SPI device is connected

Hello I am i have connected an MCP23S17 spi GPIO expansion, upon testing it with the sample code from here, It does not seem to work. There could be many reasons why this is happening. I would like to ...
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985 views

Read/Write to SPI NAND using RPI

I have an SPI NAND flash that I want to read/write the data to it using Raspberry Pi but since flashrom doesn't support SPI NAND and I couldn't find any tools that can do SPI NAND reading raw from the ...
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Can't set modes 1 and 3 in Auxillary SPI(1)

The auxiliary SPI will not accept modes 1, or 3. I’ve enabled spi1-1cs, and /dev/spidev1.0 is created. I can send and receive data but only SPI_MODE_2 and SPI_MODE_0. Setting to mode 3 produces a file ...
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Number of SPI devices limited just by CS pins? And pin assignment flexibility question

I've done some research, but not probably not enough, as I'm still confused some. First of all, I've got a Pi rev 1 Model B (with the 26 pin connector) and two devices: The Waveshare AD/DA board and ...
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590 views

Rpi4B buster SPI CAN Bus Interface Problem

I'm using PI4 OS Buster. I want to connect 2 canbus interfaces so I will be able to read both of them at the same time. this is the connections I have made GPIO CAN HEADR ...
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7k views

How to connect ST7789 LCD to Raspberry Pi

I'm trying to connect to this LCD ( sry 4 japanese page:( use translate plz ) This monitor driver is ST7789, 7pins.[GND VCC SCL SDA RES DC BLK] And now I'm connecting to pi like this https://imgur....
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SPI_Communication on Raspberry

for two weeks I have been testing the serial communication on my raspbrery pi2 and the microkontroler STM32G4. for the UART communication there is no problem however the SPI communication does not ...
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Using ENC28J60 on /dev/spidev1.0 or /dev/spidev1.2

I'm forced to use port /dev/spidev0.0 with a camera that I'm not able to configure at this time. Hence I need to change my current configuration where I'm using ENC28J60 on /dev/spidev0.0 and move it ...
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Control two SPI devices at the same time

I have a problem with Raspberry Pi 3b+. I need to connect two DACs (MCP4911) to SPI bus 1. The two DACs are expected to output the different DC voltage level. However, I found that when I connected ...
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Raspberry Pi 0 W SPI ioctl() call failure

I'm trying to setup my Rasperry Pi 0 to use two SPI ports simultaneously I need such configuration since I need: to connect this board trough ETHERNET to a local LAN; to collect video stream from a ...
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707 views

Choosing GPIO for Chip select SPI on Rpi 3B+

I would like to ask what GPIO pins are best suited for Chip select. The Raspberry Pi 3B+ and Raspberry Pi 4 has 2 chip select GPIO 7 and GPIO 8 but i have 6 slave devices (MCP3008 A/D converter). As ...
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Write to spi EEPROM in Raspberry Pi 4

The Pi4 has 512Kb of EEPROM which hold the bootloader. Does anyone know if it is possible to write to spi memory to be used in programs in the user space without corrupting the bootloader? Is there ...
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255 views

Boot behavior, Pi 3 B+ won't boot with GPIOs connected, 3 B boots fine

I have a 40 pin ribbon which connects an RPi 3 B (SPI and GPIO) to another microprocessor. It seems to work fine on a 3B. I've recently found out that if I connect a 3 B+ instead the Pi will not boot, ...
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High level of noise of SPI pins on RPi Zero W

I have a zero W powered via USB from a laptop. I have setup up for the SPI drivers and run a very simple test program which is: import spidev import time spi = spidev.SpiDev() spi.open(0, 0) ...
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spidev sanity check not working

ArchARM on Raspberry Pi 3, spidev installed from AUR. I'm trying to control a Waveshare device via SPI, and can't get SPI to work from Python. The most basic sanity test I can think of is failing: ...
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I want to multithread raspberry pi spi0 and spi1

I'm controlling two ssd1351 oleds in Raspberry Pi. When I tested using one spi bus, I see the images on both screens differently. (One eye is closed first) So, I wanted to threading another spi bus ...
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How do I connect Raspberry PI SPI pins to LED Segment via SPI?

The led segment (SPI Slave) I have got has the pin names - VCC, GND, DN, CS, CLK. The raspberry pi model is 3 model B version 1.2. The segment model is XC-3714. Is my understanding correct here that ...
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510 views

Raspbi spi CS line won't drive low

Raspberry pi 2 Model B V1.1 Not sure what's happening here, everything should work. Tried different cables, different pins on the analyzer, different laptop... the CE0 line won't go low. Currently ...
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197 views

2.5 V and 3.3 V on Raspberry Pi 3 MOSI line

I'm trying to read a SPI sensor via the raspberry pi, but I seem to be getting strange voltage levels on the MOSI line and no response on the MISO line. The chip-select line and clock lines make ...
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301 views

How to solve Argument list size exceeds 4096 bytes when working with large number of DotStar LEDs

I'm working with an array of ~1400 dotstar LED's running off a Raspberry Pi 3 B+ with raspian 4.19. The program is in python 3.5 using the DotStar package and I'm running into an issue. Specifically, ...
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is there a way to change SPI clock in shell or bash file?

I would like to write a bash to light up an OLED screen with SSD1306 driver, I can use below code to send commands: echo -ne $cmd > /dev/spidev0.0 however the SPI clock seems too fast for SSD1306,...
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210 views

Fluctuating SCLK voltage with increase in frequency

Raspberry pi newbie here. As part of my academics i was working on Raspberry Pi 3 B+ , Raspbian OS kernel 4.14.98-v7 and i was testing protocols and i am stuck at SPI. I am running spidev_test.c from ...
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272 views

CE1 not going low for pigpio.spi_open() with flags

I'm attempting to modify joan's test script (https://raspberrypi.stackexchange.com/a/44320/42126) for an RPi SPI master to communicate with an Atmega328P slave. I cannot change which GPIO pins I have ...
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Pi 4 I/O interface options... and where to find them

The BCM2711's hardware documentation lists multiple I/O interface options. Among others these are: up to 6 × I2C, up to 6 × UART (muxed with I2C), up to 6 × SPI (only five exposed on Raspberry Pi ...
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312 views

Speed up SPI transfer

So I need to transfer a byte on the spi interface on raspberry pi. Here's my code in python import spidev import time import binimp fhandle=open("white.txt") initial=binimp.extract(fhandle,'192','...
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SPI0 and UART0 interference caused by SPI interrupt

I have a raspberry CM3 running a custom Linux version created by buildroot (kernel: 4.19.44-v7). The CM3 is configured to be part of a measurement system that is used on a quad-bike (so a lot of ...
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SPI Display – fbtft connects to wrong frame buffer

Today I installed an SPI display to my pi. I'm using fbtft and follow the wiki. I don't want screen mirroring, but force the SPI display to be a secondary monitor. I discovered, that fbtft connects ...
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How can Rpi read ADS1256 ADC Data

I am using the AD/DA Hat from WaveShare https://www.waveshare.com/wiki/High-Precision_AD/DA_Board I want to realize a continuous readout of the data. It worked very well so far, but I am not so ...
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SPI NOR Flash: Unstable reads

So I hooked up an Winbond 25Q256JVEQ to my Raspi3 via SPI (spi0.0) and want to read its content. I use the jedec-nor-spi dtoverlay so its available as MTD. However when I want to read the chips ...
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139 views

Why Raspberry Pi Zero W is missing to log data constantly every second?

I'm doing a project where I want to record IMU (Inertial Measurement Unit) readings. I want to use pretty high sampling frequency and I'm using Raspberry Pi Zero W to send PWM signal of 800Hz to ...
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Cannot Use SPI frequency above 500 kHz

I am running Arch Linux ARM on a Raspberry Pi 2 Model B, and I am attempting to communicate with a TFT display. I am writing a kernel module to interface with the display using SPI, and it works, but ...
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SPI driver for communication

I want to load my kernel module which communicates with my device over spi interface. I have tried loading my modules but it's showing spidev is already installed. I see 2 modules named spidev and ...
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1k views

Using two SPI ports simultaneously on Raspberry Pi 0 W

I'm trying to use two SPI busses on Raspberry Pi 0 W. I found some hints around but I really cannot understand how to use it and if there are restrictions on it. On this thread it seems that the ...

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