Questions tagged [spi]

SPI is a low-level 3 or 4 wire serial bus interface with clock (SCLK), data in (MISO) and data out (MOSI). The fourth wire is a Slave Select to uniquely select a device on the bus. This signal is usually active-low. Slave Select, Chip Select, CS#, SS# stand for the same function, typically. Be sure to check the datasheet, though. The SPI bus is a *de facto* standard lacking the formal specification.

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Unable to get SPI working on STM32 Cortex-M3 (Blue Pill) with CMSIS

I am trying to connect to an RFM95W module using the Cortex-M3 Blue Pill from ST. I am an embedded novice but know my way around linux, so I used the below code on an Rpi3 to connect to the chip and ...
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ATmega328p will not enter programming mode

simulate this circuit – Schematic created using CircuitLab I'm trying to connect a ATmega328p and Raspberry Pi together, communicating via SPI. The Pi is Master and is used to program the ...
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STM32F0 SPI--what am I missing?

I'm trying to send SPI data to a MAX7219 from an STM32F042 (the protocol is one-way without MISO). I must be missing something very obvious. With the code below, the only visible side effect is the ...
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USB camera to dev board via SPI/I2C adapter [closed]

I would like to have an attempt at getting a USB camera module send still shots to a dev board via a USB to SPI (FTDI) adapter module. Would this work...eventually?
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SD card reader using SPI with Atmel SAM G55J

I have a custom board using an Atmel SAM G55J (ATSAMG55J19A-AU) and I'm trying to get the SD card reader to work - which is connected to SPI0. I'm using the SD/MMC ...
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SPI/I2C chip, CS# pin pullip for I2C operations

I have a question regarding all sensors offering to work in either SPI or I2C mode. I am having some issues working with a MPU9250, but think it is a general question: When working in I2C, the MPU ...
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How to read from the FM25V20A-PG memory device using spi?

This is my first time working with SPI. I am trying to write and then read two bytes of data from the FM25V20A-PG external memory. The data sheet for the device can be found here: https://www....
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Unable to receive packets on ENC28J60

I am using a CC1352P1 launchpad from TI and trying to connect it to ENC28J60 for ethernet. I am able to transmit messages to my computer such as an ARP request, and the computer recognizes it and ...
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158 views

Unable to interface BeagleBone Green with MCP3008 ADC using SPI

I am unable to interface MCP3008 with BeagleBone Green. I am trying to set communication in mode 0 (CPOL=0 CPHA=0), the built in frequency in dts is set to 1MHz. Things I have tried: Enable device ...
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What are disadvantages of using SD card SPI mode besides reduced data rate?

The "SD Specifications Part 1 Physical Layer Simplified Specification Version 2.00" states on page 93: The SPI standard defines the physical link only, and not the complete data ...
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Problem writing to EEPROM in Allegro ACS71020 through SPI

I can't write all the EEPROM registries in the ACS71020. Before every writing I write the unlock code to 0x2F. Only the first writing takes place (register 0x0B), the others do not. In the datasheet ...
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Identifying type of serial connection interface

I am having an FPC1020A fingerprint sensor which according to its specifications offers an UART and an USB interface. The images below show both interfaces: As you can see in the second picture the ...
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communications between devices over • a serial interface

Question: If a word contains 4 bytes, calculate the efficiency of a write to three significant digits. Consider the word only as "data", with everything else overhead. Also, ...
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ESP32S: More than two SPI channels possible?

In a test with an ESP32-CAM, I was successfully able to use SPI with pins 2, 12, 14, and 15: ...
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Micron NOR unused pins have pull-ups. Any danger just leaving them there?

I have a board designed for a dual-die Micron MT25QL512 QSPI NOR flash. These parts are in short supply, but the board fabricator had some single-die MT25QL128, and used them instead. The single-die ...
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SPI read error with MCP2515

In an attempt to interface a motor controller, battery management system and maximum power point tracking device on a CAN bus, I used the MCP2515 and TJA1050 CAN breakout board. All these devices send ...
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How to connect an SPI angular sensor (AVAGO AEAT-9000-1GSH0) with RS485 transceivers to an AVR microprocessor?

I need to connect an AVAGO AEAT-9000-1GSH0 angular sensor to an ATMEGA32U4 processor. I designed two versions: one using IC-s, one using resistors. I do not now witch of my two designs is better (or ...
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TLV5606 interfacing

Has anyone had any experience interfacing the TLV5606 DAC with a microcontroller (via SPI)? I'm having trouble getting any output from the DAC, which I suspect is down to my code. Does anyone have ...
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DSPIC33 - Simple Code for SPI

Unsuccessful, we have been trying to: Using our DSPIC33, set up the SPI slave device which expects mode 0 (clock polarity = 0 and clock phase = 1. Remember that microchip devices let you set clock ...
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ESP8266 SPI pinout

I'm new to the whole development board thing and I've just started experimenting with an ESP8266-12E module. Unfortunately I am unable to get the SPI display working. It works on an Arduino UNO, so I ...
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STM32F407 Discovery Board DCMI to SPI Output [closed]

I am currently attempting to use a STM32F407 Discovery board to display images captured with a OV2640 CMOS detector on a ILI9341 2.2" TFT SPI LCD. My goal right now is to take a single snapshot and ...
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MAX7219 led matrix prints unwanted artifacts when it is powered up

I’ve got Led matrix 32x8 which is driven by MAX7219. Like this: MAX7219 Dot Matrix Module Microcontroller 4 In One Display with 5P Line When I power it up, I can see different glitches. How to power ...
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SPI internals _ missing MISO clock during read operation

I am currently writing C++ code to utilize SPI protocol. I am using popular library as a guide. Run into few questionable areas and after some discussion on the library board forum I have been told "...
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How to connect 3 slave devices to one master if there are only 2 chip select pins

I need help figuring out how to interface the microcontroller Teensy 4.0 to three ADCs via SPI. The microcontroller only has 2 chip select pins according to its spec sheet. How can I connect to three ...
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Initializing to MicroSD Card with Arduino produces error code 0x43, 0xff

I am trying to interface with a 32GB MicroSD card with an Arduino Uno, but the code consistently fails at the initialization stage. Below is my schematic (sorry for the horrendous schematic, I'm not ...
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Issues with SPI slave select on PIC18F4321

I'm trying to get 3 PIC18F4321s to communicate using SPI, with one of them in master mode and the other 2 setup as slaves. We first got it working with just 2 devices and no SS (slave select) signal ...
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Quad SPI Frequency

I am using a QuadSPI interface in MPC5606S Can someone help me how to arrive at the maximum and minimum clock freq of SPI and IO lines?
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SPI broadcast: talk to many slaves

I need to do similar things to this question on Stack Overflow: "Using Serial Peripheral Interface (SPI) to talk to several slaves simultaneously " I have no confirmation if it works. Has someone ...
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Inconsisent SPI data transfer with MAX31856

I am using an Arduino to communicate with a MAX31856 on a custom-built PCB. The Arduino is loaded with this library, which seems to be working correctly. Unfortunately the data being read by the ...
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ATmega328p: Does SPI conflict with timers TC1, TC2 or interrupts PCINT2, PCINT0?

My code - based on my library MultiTrans - uses timers TC1 and TC2 as well as interrupts ...
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Unable to read back registers via SPI on the ENC28J60 Ethernet chip

I am using a CC1352P1 Launchpad from TI to connect with an ENC28J60 SPI-Ethernet bridge chip. I wanted to confirm first that I am able to get a response from the ENC28J60, so I tried to write to a ...
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STM32F4xx barebones SPI (HAL initialisation)

I am working on a piece of software for an STM32F4xx device which started from a STM32CubeMX generated project. I am using the SPI peripheral which has been initialized using the HAL library. This is ...
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s25fs256s serial flash not responding with RTD2660

Hello guys,, I am interfacing RTD2660 with s25fs256s serial flash using SPI. but when i send the command_type(0x46 (comman instruction type is read)) and command_data(0x9f (command for ...
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DRV8889 SPI Commands

I've been having some issues diagnosing the relationship between writing to the registers through SPI commands and stepping the motors. That is, it seems like when I write SPI_STEP=1 (and STEP=1) to ...
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Where are all the multiplexers?

I am trying to implement a circuit where 2 SPI drives (basically two masters) speak to 1 slave. Both operate on a 3 wire SPI. Keeping that in mind I was going to have the CLK and MOSI of both as ...
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204 views

Does not trigger an interrupt DMA when reading SPI. Last byte transaction not coming

I use DMA for reading with SPI flash using USART. MCU - master, flash - slave. I read 1029 bytes per transaction. Exchange algorithm: I activate the flash (CS = 0) I configure the DMA channel to ...
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Where MOSI is triggered low or high

Sending and Receiving Data //Function to send and receive data for both master and slave ...
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ESD SPI/ISP bus protection

I am designing a board based on the Atmega328P microcontroller. For this controller there is an ISP connector for programming. This connector has the following pins: MOSI / MISO / RST / SCK. There is ...
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How to code SPI Slaves? [closed]

This is a normal sequence for an SPI Read: I want to code for an SPI slave. How is this normally done? How can the slave respond so quick (in the next bit!) with the appropriate data out after it ...
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MCP23S17 IOCON register values do not update correctly

I am currently testing the functionality of a Microchip MCP23S17 SPI 16-bit GPIO port expander for an application with a number of external inputs & outputs. The initial configuration of an ...
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How to select the compatible USB to SPI IC Programmer?

I built an image of Coreboot (open source firmware) and wanted to flash it on the Minnowboard Max. SF100 is compatible to do the job (as described in this article). However, I want to be clear on the ...
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LSM303CTR 3-wire SPI and I2C - conceptual problem

I'm trying to interface LSM303CTR e-compass from ST-microelectronics with microcontroler. Due to design limitations I have to use 4-wire SPI. This MEMS device has option to switch beetween 3-wire ...
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STM32F103 SPI Pinout Problem

I am currently working on a project with LoRaWAN technology using STM32F103C8T6 microcontroller. For LoRa I am using SPI in Full-Duplex Master mode (spi1 specifically) and in CubeIDE when you activate ...
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What is need of transmission modes in Serial Peripheral Interface

I am going through SPI transmission for implementing in FPGA, While researching, In few articles such as https://en.wikipedia.org/wiki/Serial_Peripheral_Interface and this https://web.archive.org/...
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.96 inch TFT with ST7753 and AVR - can't draw individual pixels

I bought this from aliexpress: https://www.aliexpress.com/item/32859042892.html It seems to be a good display, even a bit higher res, than advertised, however, I'm having trouble doing anything more ...
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What is the difference between SPI,SCI and SDI?

Hi I'm trying to interface an audio codec chip VS1053B with my STM32L476 Microcontroller. But in the microcontroler there is SPI interface and in the VS1053B chip it is SCI interface with few extra ...
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CMOS Flash vs SD: Can I put a Gamecube Memory Card in an SD reader?

Backstory I've decided to run "Homebrew" on my Gamecube (and writing Homebrew for n00bs to document the process). Unfortunately, it seems that there's no way to do this without buying special ...
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629 views

SPI with differential signaling

Standard SPI uses single-ended signals. Is it possible that a communication uses SPI protocol but the signals are physically LVDS?
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MCP2210 - Plug n' Play HID Keyboard

I'm working on something at the moment that uses an ESP32. I would like to have simple strings that I can specify within the ESP32 code to automatically "type" on the screen. For example, if I did ...
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MicroSD card stuck after CMD8, responding 0x5 before next CMD is issued

I have a problem for which I can't find the solution in previous topics. I'm using a microcontroller to read data from a Kodak 2GB Micro SD Card. I want to write a minimal driver in SPI mode, no need ...