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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538 views

RF24L01 - RF24 Creation Segmentation Fault in Raspberry

What I have Raspberry Pi 3 B RF24L01 RF24 Library TMRh20 How I've Connected It Based on the library indications: RF24L01 pin | RPi 3B 1 GND | 9 GND 2 VCC | 1 (3.3V) 3 CE | 15 (...
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566 views

Setting SPI chip select every few bytes with buffered read

I managed to successfuly read packets from MCP3208 ADC using SPI on Raspberry Pi - I can do that both with spidev.h library or with WiringPi. The problem is that when I want much higher speed, I can ...
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Using Python's Rpi.GPIO library to manually toggle SPI chip select. Is this OK?

I recently designed a PCB that features several SPI devices. One of the devices is the Microchip MCP23S17 GPIO expander (http://ww1.microchip.com/downloads/en/DeviceDoc/20001952C.pdf). I have the ...
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284 views

What's so “special” about the two SPI chip select digital outputs?

In the majority of Pi SPI documentation, it makes reference to the fact that 2 SPI chip select channels exist. However, from my previous experiencing with the Raspberry Pi and other microcontrollers, ...
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750 views

What's wrong with my SPI interface?

I have been trying to get SPI working so that I can use Flashrom to program a BIOS chip with Libreboot. I am using a Raspberry Pi Model B+ connected via short F-F jumper wires to a Pomona 5252 clip ...
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1answer
638 views

Use RFID reader AND a 4x4 matrix keypad with breadboard

I am trying to set up a pi to use rfid to scan a card and if the card is correct, the user will enter in a 4 digit code into a 4x4 matrix keypad. Each device works perfectly fine independently however ...
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781 views

Connect SPI display to raspberry pi zero

I would like to use this display with my raspberry pi zero w. http://uk.farnell.com/midas/mcot128032cy-ws/display-oled-tab-128x32-pixels/dp/2769715 I can see there is a flat ribbon for the SPI ...
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589 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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1answer
791 views

What cable do I need to connect an SPI (4-wire) interface?

I have received an e-ink display as a gift. The connection interface is SPI. I would assume that I need to find a cable/adaptor that would output to different GPIO (I have a breadboard so it should be ...
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1answer
335 views

Conflicting dtoverlays and framebuffer

I have a RPi3 with latest standard kernel. I am making use of spi1. In config.txt I have the line: dtoverlay=spi1-3cs. I have 2 ADC's connected to spi1 and all seems fine, using an HDMI screen to ...
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What are my options for using my Raspberry Pi 3 as an SPI-Slave?

It seems that it isn't officially supported (no official drivers) according to a similar question on this site. Do I have to write the driver myself or are there inofficial drivers that I can use? Is ...
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129 views

Access more than two (2) slaves on spi0

Supposedly, there is a new driver that supports arbitrary GPIOs for SPI0 channel select, that is configurable via the device tree. Everything I try only half works. The hard works. If I toggle the ...
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394 views

Accessing 3+ SD/MMC /dev/mmcblk devices

I've successfully followed some instructions for access 2 SD cards via SPI on a Raspberry Pi 3: https://ralimtek.com/Raspberry_Pi_Secondary_SD_Card/ How do I configure it to access more than 2 SD ...
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1answer
206 views

What libraries/code to I need to use a MyoWare muscle sensor with a Raspberry pi?

My robotics class is trying to take signals from a MyoWare Muscle Sensor and feed them to a Raspberry Pi Zero. For ADC, we are using a MCP3008 chip. Because most people use Arduinos for these sensors,...
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BCM.GPIO and BOARD.GPIO

For a school project I wanted to use a 128x64 OLED i2c OLED screen and a RFID reader. I tested everything separate and it worked, but when I wanted to join everything in my main program it failed, ...
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In simultaneous use of SPI0 and DPI Mode 3 interfaces, can SPI0 CS0 be moved to a pin other than 8?

I am attempting to design a device using a Pi Zero which needs to connect to both an ENC18J60 SPI ethernet controller, and a VGA monitor via Mode 3 DPI and the Mincepi Pi Zero pi2vga schematic. While ...
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2answers
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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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SPI always reading all zeros, including during loopback test

I'm trying to get started interfacing my Pi 3 (running Stretch) with an ADC via SPI, but all I'm ever reading from SPI are zeros, including when I wire GPIO pin 19 to wire 21 for a loopback test (and ...
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552 views

SPI doesn't work because of device tree

I have the same problem as this person: SPI enabled in device tree, but I can't use it I tried commenting in the original thread but the community rules don't allow me to comment because I don't ...
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1answer
643 views

Compute Module 3 + PIGPIO SPI, Clock signal but no data

So I'm trying to write to as spi eeprom using the pigpio library, but I have the problem of only the clock line going active, none of the data or select lines. I'm debugging the signals with the ...
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2answers
576 views

Raspberry pi SPI return strange value

I'm using MCP3008 ADC to get Analog signal from sensor. I connect ra-pi with MCP3008 like this. And this is real. And I found MCP3008 SPI Library. I expected this kind of output. But strange ...
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1k views

nRF24L01+ only correctly retrieving status and config registers

I didn't write here before, though i get in often to find solutions for my problems with raspberry, so thanks in advance. I got the following problem with nRF24L01+ radio breakout board. Here is my ...
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562 views

Linux SPIDEV clock timing issue

I am using a Linux board called NanoPi Neo based on the H3 chipset. I got the spidev driver working and it appears as /dev/spidev0.0 I am trying to use a SPI module called RF24L01. However, I was not ...
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1answer
1k views

Link spidev and can device

My pi3 has 2 mcp25625 devices connected. The first is connected to spidev0.0, the second to spidev1.2. They both work correctly, after making an overlay (based on https://github.com/raspberrypi/linux/...
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319 views

Driving SPI MOSI and SCLK pins with external power and transistor

I'm building a display controller with a Raspberry Pi. Basically we're trying to control a set of small OLED screens through the SPI interface. All of the OLEDs are tapping off the same MOSI and SCLK ...
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518 views

1.8" ST7735 TFT display on SPI bus fickering, refresh rate seems too fast

I have four identical displays I purchased on Amazon: https://www.amazon.com/gp/product/B01DKGJF1K/ One of them is visibly flickering, making the display very unpleasant. I took a "slo-mo" video ...
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1answer
399 views

Why does Waveshare board use GPIO pins for Chip Select

I am researching the Waveshare High-Precision AD/DA Board. Why does this board use GPIO pins as "Chip Select" pins? My understanding is that an SPI bus typically uses one of two "CE" pins for chip ...
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1answer
179 views

Using GPIOs as Chip Selects on Raspberry pi 3 while using Windows IoT core

I need to control 5 SPI devices using Raspberry Pi 3 and Windows 10 IoT core. But, as we know, there are only 2 SPI Chip Selects available. Is there any way that I can use the GPIO of the Raspberry Pi ...
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1answer
577 views

Where is the documentation for the SPI mode bits?

I'd like to configure the clock phase, polarity, etc. of the SPI peripheral on my Raspberry Pi. While I can just try stuff and observe the results on an oscilloscope, I'm partial to reading SDK ...
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How does one use the SPIDev xfer command?

I can't figure out what the input/output of the SPIDev xfer command is supposed to be. I know it accepts an array of integers but what does it mean? I initially thought it meant the byte array of an ...
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1answer
117 views

Unexpected behavior of ws2801 when headless

I am using a raspberry pi 3 with a fresh installation of raspbian-lite to control a strip of ws2801 RGB leds. I followed the tutorial found here: https://tutorials-raspberrypi.com/how-to-control-a-...
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3k views

Multiple SPI Slaves on Raspberry Pi

I know that Raspberry Pi has two Chip Select(CS) pins CE0 and CE1 in its header. However when I look to GPIO pinout. I see that BCM 19,20,21 pins are related to second SPI bus. Is there really a ...
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1answer
689 views

Raspberry Pi SPI and interbyte delay

I've got a position sensor that I need to read out via SPI from the Raspberry Pi. The sensor is a MLX90316, that requires interbyte spacing in the SPI message. Typically, I need something like this (...
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3answers
8k views

How to enable SPI1 and SPI0 at the same time?

I have installed a LCD screen that use my SPI0 bus and I2C but i want to connect my RFID reader to the same raspberry. My lcd screen can you see here: https://www.adafruit.com/product/1601 SPI1 will ...
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1answer
1k views

Use SPI pins from ASP.NET Core application on RaspberryPi 3

In my project I have a Raspberry Pi 3 with Windows IoT OS, and I have a RC522 RFID reader. I would like to use this component (RC522) from my ASP.NET Core application. I would like to use this ...
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1answer
582 views

filenotfounderror with SPI function

I am currently working on a personal project and im having some problems troubleshooting this particular error. python3 ecg.py Traceback (most recent call last): File "ecg.py", line 30, in <...
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1answer
1k views

Dual output SPI using Raspberry Pi 3

I'm trying to make data acquisition device using TI ADS7851 and a Raspberry Pi 3, but ADS7851 has 2 data output.. I have no idea how to connect. ADS7851's serial output is: 1 sclk 1 /cs 2 sdo (sdo-a,...
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How to use SPI on Raspberry Pi 3?

I have a Raspberry Pi 3, and I would like to use it to communicate with an SPI device. The pins from the SPI device have been connected to the appropriate headers on the board. Windows 10 IoT ...
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1answer
373 views

Raspberri PI 3 read all 0's from 23LC1024 SRAM chip over SPI

I am using several 23LC1024 SRAM chips to share data between an Arduino and a Raspberry PI 3 running Windows 10 IOT. I am using SPI to send and read data from the 23LC1024. I am having trouble ...
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2answers
7k views

What is the purpose of SCLK pin of SPI protocol?

I read about SPI(Serial Peripheral Interface) protocol and try to understand their pin functionalities. Where i read about SCLK pin, which is provide serial clock to synchronize the master and slave ...
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0answers
189 views

Use SPI to clock sensor and stream data using DMA

I'm looking into a issue on a Pi with SPI port, to clock continuously and stream data to memory area using a DMA. The sensor I connected on SPI on a Raspberry Pi 3, should be clocked with more than ...
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3answers
2k views

Possible SPI issues around NRF24 operations post RPi system update?

I have a number of RPis that communicate with Arduinos via BLavery's lib_nrf24.py (which appears to be derived from Barraca's pynrf24). Recently several of the RPis automatically updated via apt-get ...
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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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2answers
5k views

How to connect multiple spi devices (ADCs) to Raspberry Pi?

I want to connect 8 ADCs to the Raspberry Pi, however, the board has only 2 Chip Enable pins. I searched around a bit and the option that I found was to use arbritrary GPIO pins to act as CE pins. And ...
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1answer
664 views

SPI Communication with ADS7851

I'm currently trying to communicatie Raspberry Pi 2 B+ with ADS7851, an adc chip made from TI. ADS7851_DATASHEET I've done pretty much of research, but I'm still stuck on how to communicate in SPI ...
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1answer
5k views

SPI enabled in device tree, but I can't use it

I am trying to use SPI interface on Raspberry Pi 1 B (OS: Raspbian July 2017, kerenl 4.9.5). To do this, I am using wiringPi. I confirmed that wiringPi works via gpio readall To load SPI: gpio load ...
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1answer
3k views

Unable to activate SPI module on Raspberry Pi Zero W running on DietPi

Ater setting up my Raspberry Pi Zero W with DietPi v150 I activated I2C module via the dietpi-config tool. However, I need to use SPI in addition and since there is no such option in the config tool I ...
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1answer
4k views

Reading all channels MCP3008

I have a problem with reading data from adc convertor MCP3008 10bit. I found a python script from adafruit that give data value from all channels (CHO TO CH7). I added a picture with my results and ...
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174 views

Setting maximum process pause time - need to read spi data with less time gaps

I am using a raspberry pi to grab data through a SPI port. Attached to the SPI port is a PIC, programmed so that it samples on an A/D at 12.8kHz, and stores the samples in a 256 long buffer. (to cope ...
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64 views

How to change register values on Ripi 3 model B

I have an issue with my SPI0 CLK 'pausing' between every byte that is sent from the Pi. I found in this handbook (entered in comments) that I can adjust some register values. Is there a way to do this?...

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