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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127 views

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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186 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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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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Varying possibly broken behavior of different GPIO pins on bitbanging LED display driver

I connect Raspberry Pi 3 b+ directly to 8x8 LED display, packaged with max7219cng display driver. To control GPIO pins, I'm using baremetal code, written by myself. For working with GPIO I've ...
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76 views

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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413 views

How can the SPI interface suddenly stop working?

I've got the following issue: I've attached a display to my Raspi 3B by using the SPI interface. It has been working fine for months, but a couple of weeks ago, the display suddenly stopped working ...
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270 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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86 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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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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What is MOSI in Pi?

What is the significance of these pins MOSI MISO and SS? I am looking at SparkFun DeadOn RTC Breakout - DS3234
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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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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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105 views

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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187 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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98 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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176 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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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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1answer
105 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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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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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 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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734 views

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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826 views

Reading only 0 from ADC using RPi SPI

Everytime I try to read analog channel 0 from ADC, it only prints 0. I am confused why. I shorted MISO and MOSI on my RPi to check SPI send/receive and it was working. But if I test it after properly ...
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517 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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2k views

How to check if SPI is enabled and functional on Raspi 3b+?

I have run raspi-config and enabled SPI and also verified that /boot/config.txt contains the line: dtparam=spi=on However, when I run lsmod | grep spi I get the following: spidev ...
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Find out whether SPI is enabled or not

I have a game that needs SPI. In the installation instructions, I noted that SPI has to be enabled via raspi-config. Now, I'd like to check in a shell script whether the user has activated SPI or not....
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611 views

How do I debug an LED strip that isn't working?

I've scoured the forums here and elsewhere and can't exactly figure out what my next step should be. I've followed this tutorial https://tutorials-raspberrypi.com/how-to-control-a-raspberry-pi-ws2801-...
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101 views

Two data parsing frames for SPI reads of MCP3008 ADC, any advantages or disadvantages of either one?

I am reading an MCP3008 ADC using pigpio, I've abstracted the script below. I have also found a slightly different construction or parsing of the three SPI command bytes and reconstruction of the ADC ...
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388 views

Using FLIR Lepton3 module with Raspberry Pi 0 W low frame rate issue

I'm trying to use FLIR Lepton 3 module with Raspberry Pi 0 W board running Raspbian 9 Stretch. I followed all official FLIR recomendations: connected Lepton module to Raspberry in the correct way (...
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73 views

Using waveshare LCD and SPI1 for LEDs

My problem is that I cant get SPI1 and the LCD screen to work at the same time. Only SPI1 with the spi1-1cs overlay worked and only the waveshare35a overlay working, I tried to make my own overlay ...
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1answer
462 views

Adding a USR-ES1 W5500 chip for Raspberry 3 A+

I am currently thinking about a project in which space should be kept to a minimum. Now I am using the A+ model because it is smaller however I do need an ethernet port. So what I am planning to do ...
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101 views

Cant read both SPI Buses of Raspberry Pi 3B+

I want to read 3 analogue sensors simultaneously. I have successfully connected 2 sensors using a MCP 3002 A/D converter which is connected to CS0 of SPI 0 of raspberry pi and I have activated 3 more ...
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CAN bus read on RPI3

I have 10 CAN IDs on the bus and would like to read all the 10 IDs every 0.1 seconds. I was able to write the code below but it shows me one message only. import can bus = can.interface.Bus ("can0", ...
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Configure SPI from Kernel Space by writing to the SPI Registers

I'd like to write my own SPI driver to configure the SPI interface by means of writing to the CS, FIFO, and CLK SPI registers. I have disabled the SPI interface in raspi-config. I followed the ...
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1answer
1k views

I am using a RFID reader module MFRC522 with my raspberry pi but it is not working with python 3

I am using RFID reader module (MFRC522) with my raspberry pi and when I run the script with python 2 it works fine and reads the RFID tag but when I run it with python3 I get an error - No Module ...
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1answer
118 views

SPI sending function

I'm currently reworking a project from someone who graduated a few years back and I'm supposed to change the function of his work for a bit. I have trouble understanding these few lines from SPI ...
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2answers
1k views

5V-3.3V Sensors Confusion

Most of the sensors available in the market requires 3.3V-5V. The GPIO of the Raspberry Pi is 3.3V max only and not 5V tolerant. I have seen tutorials around the internet that they supply the sensors ...
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1answer
4k views

Getting a 1.44" TFT ILI9163C screen to work with SPI

I am working on getting my very very very cheap chines display working. As far as I can tell, its a TFT 1.44" 128x128 SPI display (printed on the board) - and the internet seems to direct me towards ...
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133 views

SPI voltage level

I had troubles reading an IC (ADAS1000-4) with my raspberry. As soon as I connect the chip to the SPI bus of the Raspberry, the Low voltage doesn't get as low as I expect (please have a look on the ...
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349 views

MAX7219 7-segment via SPI not working

I am following these instructions to get a simple 7-segment display working: https://github.com/rm-hull/luma.led_matrix My problem is that as soon as one of the 3 SPI Pins are connected the digits ...
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1answer
878 views

Connect multiple SPI e-paper devices to a single Pi

So I'm thinking of getting these 2.9" displays: https://www.waveshare.com/wiki/2.9inch_e-Paper_Module#Working_with_Raspberry_Pi they come with an SPI interface that can be connected to the Pi. Is it ...
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101 views

piscope SPI pin activity even though the SPI device is not connected

my final goal is to use python (spidev) to communicate with a BMS chip. Until now I was quite unsuccessful, thats why I wanted to use piscope to track the activity of the SPI pins. The device is not ...
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644 views

SPI DMA in Raspbian

Is it possible to access the SPI DMA on a Raspberry Pi running Raspbian without using custom drivers by directly reading and writing to the associated hardware registers? I assume the register ...
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1answer
3k views

How to use Bluetooth, SPI and UART at the same time with an RPI3?

I just bought a Rpi3 and a Kuman 3.5" screen to make a minimal computer. I also have a PN532 to do NFC. My configuration: - Kuman 3.5 screen is connected to SPI0.0, touchscreen to SPI0.1; - I need ...
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67 views

How do I find which pins my TFT display is using?

I have a TFT Touch Screen Display from Tontec that I'm using for a project. According to the product description the display only uses 8 pins. However, the connector cable takes up 26 pins worth of ...
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Why won't my Raspberry Pi connect using SSH when NRF24L01 or ATTiny85 are Connected via SPI?

As the question states, my Pi (3 B+) won't accept SSH connections (times out) when I have either my NRF24L01 or ATTiny85 boards hooked-up. I hook both up (at different times of course) to pins 17, 19, ...

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