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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 (...

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28 views

3,5" LCD display not work in raspberry pi

I have bought a 3,5" display from ebay, and I installed it onto my raspberry pi 3. I installed the LCDshow drivers, but when it restarts the display is white. I tried to start the gui, but it gives: ...
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123 views

Imprecise result after bitwise operation on GPIO registers

I am using a Raspberry Pi(Model 1 B+) and an oscilloscope in order to program SPI with C. I am doing this by using direct access to the GPIO register. Like this: https://elinux.org/...
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30 views

Multiple Raspberry Pi zeros (no wifi) + touchscreen. Daisy-chained communication?

I'm trying to devise a solution that will connect multiple Raspberry Pi zeros together for communication between them. I'm using a touchscreen on each of them, so GPIO pins 1-24 are taken. Also, I'm ...
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29 views

Single channel SPI DMA

The documentation on the SPI peripheral says: Two DMA channels are required, one to read from and one to write to the SPI. Is this necessarily true? I have a device where I need to write a few ...
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1answer
69 views

SPI only returning zeros with Raspbian (It works with IoT core)

I am using this ADC connected to the channel 0 of my Pi3 board for reading values from a sensor. In IoT core, I was using a very simple code for testing the my device, and it worked fine. The C# code ...
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1answer
47 views

Sharing SPI Adafruit PiTFT and RFID RC522

I have a Pi Zero 1.2 connected to an Adafruit 2.8" PiFTF screen and a RFID-RC522 board. I also have a thermal printer connected to TX/RX, but I don't think this plays a part in my question. The TFT ...
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1answer
51 views

Can't blink a LED using SPI interface on Raspberry Pi v3

As a part of my PoC project, I'm using single 5050 LED made by Adafruit. I wired it like this (LED - RPi): DI (Data Input) - SPI0 MOSI CI (Clock Input) - SPI0 SCLK GND (Ground) - GND VCC (5V) - 5V ...
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45 views

wiringPi (C) , MCP23S17 , and interrupts

I've enjoyed using the wiringPi C library in various ways. Used it with vanilla GPIO, with its interrupt-handling feature, with MCP3008, MCP23017, and now the MCP23S17. However, I'm a bit stumped on ...
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22 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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1answer
37 views

Why does a communication over SPI returns garbage?

I am trying to read from a gps module NEO-6M using Raspbery Pi 3 B over SPI. It nicely works with Arduino but it doesn't want to work with Raspberry. I have used different libraries in Pyhon, even ...
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45 views

No reading for the LDR using MCP3008 with SPI on raspberry pi in python 3

I'm a beginner to RPi and trying to learn how to use SPI & MCP3008 to read analog signal in Python3. The output displays 0.0V all the times despite the change in the light intensity. Light: 0 (0....
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23 views

LIS3DSH Accelerometer attached to Raspberry - Problem to read registers SPI

I have an LIS3DSH Accelerometer (Accel 2 click from Mikroe) attached via SPI pins to my Raspberry Pi. I use the following Python script to collect data: import spidev import wiringpi as pi from time ...
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32 views

How to control SPI1 gpio port on Android-Things?

Hello Recently, I use Android-Things on Raspberry pi. and I want reader tag on RC522 so, I decided to refer to source in on Git-hub https://github.com/Galarzaa90/android-things-rc522 first I try ...
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1answer
74 views

What is the mode supposed to be for CE0 and CE1 when SPI is enabled?

I have enabled SPI on my Raspberry Pi 3, and want to know why the mode for physical pins 24 and 26 are set to Mode 'OUT' and not 'ALT0'. According to the documentation here and here the mode of all ...
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2answers
55 views

pi4j implementation for SPI communications with MCP3008 reading zeros

I have hardwired a MCP3008 IC into the SPI input on a Raspberry Pi3. MCP3008 is wired as follows: pin 10 (CS) to Pi GPIO_10 (pin 24) this is CE0 pin 11 (Din) to Pi GPIO_12 (pin 19) this is MOSI ...
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2answers
40 views

Raspberry Pi won't recognize nRF24L01+

I'm a Raspberry Pi n00b and a python beginner, but I have a lot of experience with DIY electronics, arduino and c#. I've tried everything I can think of, and I just can't get the Pi to recognise the ...
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1answer
33 views

About multiple SPI on Raspberry Pi3

I'm tying to use MCP3008 to read the ADC signal from sensors. But I need to transfer the data through the LoRa module. Which is also the SPI interdace. The example of ping pong has been done. But ...
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1answer
110 views

SPI DMA and continuous transfers

I'm building a project using the MCP3914 8-channel analog front end (ie ADC) device connected to the Raspberry Pi's SPI peripheral. The device has a continuous read mode where you request the value ...
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2answers
40 views

How to read a specific register using spi_xfer from PIGPIO

I am building a single channel LoRa gateway using the RFM95W module. I am using this github repo; single_chan_pkt_fwd, as a guide. However I am not yet using a PCB, even though it is very difficult, ...
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147 views

Reading data from MCP3551 via SPI

I am trying to read data via SPI from an ozone sensor that I have connected to the Raspberry Pi's GPIO. This set up uses a Mikro Pi click shield and Mikro Ozone 2 click sensor. The output of the ...
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1answer
85 views

pigpio spi : use an other GPIO for chip select

I'm using the Waveshare High-Precision AD/DA Board, and they not use the default chip select pin of RPi (GPIO# 7, 8) for SPI. Using the pigpio python library, I want to know how to change the chip ...
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2answers
68 views

SPI Burst Read of 2048 32bit registers

i have build a Smartmeter based on an SPI ADC from Analog Devices. The measured values are beeing transfered to an Raspberry Pi with lib bcm2835 for visualization. The lib works with single bytes in ...
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1answer
90 views

Crash on radio.begin() (for NRF24 Module )

I have connected my NRF24 module as described at bottom of this webpage. I cloned that repository and have Build using SPIDEV (I have ensured SPI was enabled and double checked that SPI module works, ...
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1answer
31 views

Wired communication of Raspberry Pi 3 Model B to Pi Zero

I am trying to make a personal robotic assistant, and i am using 2 Pi Zero's to control 2 main parts of the robot, the assistant's voice and voice recognition systems, and the facial recognition ...
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1answer
71 views

SPI vs HDMI power consumption

I'm using a Pi Zero in a portable project and wondered if there were any power savings to be made by using an SPI display over a HDMI one or vice versa.
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1answer
44 views

SPI not working on a Pi Model B

I have an issue and I think it is the SPI module not starting up. if i run this: pi@raspberrypi:~ $ gpio load spi gpio: Unable to load/unload modules as this Pi has the device tree enabled. You ...
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2answers
95 views

What creates /dev/spidev*?

I’ve got a little program that uses an spi hat that I set to start running from rc.local. It was all running fine under Jessie, but I’ve upgraded to Stretch and now it appears rc.local is being called ...
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47 views

How to improve the reading speed of a DESfire with PN532 spi reader?

I'm developing a application with PN532 card reader through SPI. I'm using libfreefare library to communicate with Mifare DESfire EV1 mainly. My problem is in the reading speed I'm getting. I've to ...
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1answer
60 views

Why isn't spidev showing up in /dev/?

I'm trying to do a spi loopback test with a raspberry pi 3 model B+ with kernel patched with RT_PREEMPT. This is the loopback test being attempted: https://www.raspberrypi.org/documentation/...
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68 views

How could I write a C function using the wiringPi SPI library to read the X and Y measurements from this 2-axis inclinometer?

How would one use the wiringPi SPI library (http://wiringpi.com/reference/spi-library/) to get the x and y readings from this SCA100T inclinometer? I understand that the function wiringPiSPIDataRW() ...
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1answer
112 views

Interface AD7193 with Raspberry Pi

I have been trying to interface an ADC with raspberry Pi namely AD7193 via SPI . For that I have enabled my SPI and installed spidev on my pi. but i dont know what to do next in order to get the ...
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1answer
43 views

TFT screen not working on Rpi A+

I have an old TFT LCD SPI screen, which I believe uses ILI9341 and would like to use it on my (old) RPi A+. Unfortunately, it just stays blank. I am not even sure it is working... My RPiA+ has a fresh ...
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1answer
188 views

USB/Bridge using MAX3421

Please, could someone help me, I am trying to use the module (max3421-hcb) with the raspberry pi 3, but I really don't know how to load this module, with the parameters, like wich GPIO will act as INT ...
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86 views

Simultaneous sampling using ADC and displaying in graphical LCD

I am using Raspberry Pi 3 Model B and MCP3008 for sampling my analog signal and the sampling frequeny is approximately 10 kHz. I need to display the sampled values in 3.5' inch graphical LCD. I just ...
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2answers
193 views

I want to use spi0 and spi1

I try to use my RPi3 and the RC522 and a touchscreen display as well so i need to put my RC522 on the auxiliary SPI1 right ? How can I do it ?
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25 views

Python3 for Max1416 Adc

While trying to connect to a Max1416epe 16-bit Adc using "spidev", I changed the r = spi.xfer2([1, 8 + adcnum << 4, 0]) adcout = ((r[1] & 3) << 8) + r[2] for reading a Mcp3008 to r ...
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1answer
116 views

ADXL345 Accelerometer attached to Raspberry Pi - Problems with Sample Rate

I have an ADXL345 Accelerometer attached via SPI pins to my Raspberry Pi. I use the following Python script to collect data: #!/usr/bin/python # -*- coding: utf-8 -*- import sys, math, os, spidev, ...
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2answers
417 views

How to achieve a high sampling speed using an ADC with Raspberry Pi?

So, I am using the LTC 2366, 3 MSPS ADC and using the code given below, was able to achieve a sampling rate of about 380 KSPS. #include <stdio.h> #include <time.h> #include <bcm2835.h&...
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213 views

soil moisture sensor analog output is 0

I'm a newbie to pi and using it for my final year project to display moisture value of soil using the soil moisture sensor. I have followed this tutorial website for the connection and code and ...
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99 views

Using LCD and 2nd SPI

Heyho :) I am facing a problem with the Spis on the Pi. I would like to use a lcd with touch with the pi zero w, but i also need a spi for high speed data link. https://www.waveshare.com/3.5inch-RPi-...
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2answers
212 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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1answer
201 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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3answers
741 views

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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1answer
55 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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273 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
234 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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1answer
358 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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1answer
73 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
101 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
100 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 ...