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 ...

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34 views

Multiplexing two SPI Master

Is it possible to switch two master SPI lines using Quad 2:1 multiplexer like (74HC257)? I want my two Master devices to access a single SPI slave (Flash). Please see attached schematics. SPI speed is ...
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1answer
32 views

MCP3008 (ADC with SPI interface) what to do with unused pins?

I'm building embedded system based on a Raspberry Pi with an MCP3008 for analog inputs. I have few questions regarding the PCB board design. What should I do with unused analog inputs on my MCP3008? ...
2
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1answer
42 views

AVR SPI shift register not clocking

I'm trying to generate parallel output by writing serial data into a shift register (SN74HC595) via SPI on an ATMega328 (SPI master) running at 20MHz and SPI running at 10MHz. The bare minimum ...
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0answers
21 views

SPI on dsPIC33 and PPS problems

I've been trying to get SPI working on my dsPic33FJ64MC802 for a few days now so I'm desperately needing help because nothing seems to be coming out of SCK1 or SDO according to the o-scope. This is ...
2
votes
3answers
114 views

SPI interfaces on microcontrollers

My question is for microcontrollers in general. Can SPI be implemented with any 3 different I/O pins granted one is a clock signal? Is there anything special with certain pins that a datasheet ...
0
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1answer
38 views

ADC speed for precision medical instrument

I am studying a bio-medical instrument where glucose in blood is measured using light reflection principle as shown: Below equation is used to determine glucose level: LED is blinked at fast rate ...
0
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1answer
39 views

Atmel SAM E70 SPI Chip-Select (SPCS) lines

I deliberate the datasheet of Atmel's SAM E70 Cortex-M7 and i have a confusion about SPI. When SPI is in master mode, it uses NPCS lines for Chip Select (Slave Select). But i can't find a report which ...
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2answers
36 views

Use SDIO pheripheral for quad SPI flash memory

I am currently doing a project using the STM32F103 micro-controller. The project requires external flash memory to store images and data for later showing on LCD. The problem I have is that I want ...
1
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2answers
61 views

SPI communication between PIC24FV32KA301 and MS5611 won't work

I am new to microcontrollers programming and I am trying to establish SPI communication between PIC24FV32KA301(Datasheet) and MS5611(Datasheet). After a week of searching and learning about SPI I am ...
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1answer
102 views

Help? SPI communication slow

I am using an Intel Edison with Arduino Breakout Board to communicate via SPI to a LS7366R Quadrature Encoder Buffer. I am using the QEB as a timer: a pulse that enters the index will shift the ...
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0answers
38 views

Touch sense controller Dout pin loading

I am working on Touch TFT LCD project where LPC2138 is host (main) controller and TSC2046 is touch sense controller for implementing touch interface. TSC2046 is having SPI interface with conventional ...
3
votes
4answers
326 views

Operating an SD card module with only two pins

My standard SD card module uses four pins: SDCS, MOSI, SCK, and MISO. However, I can only dedicate two pins of my ATtiny85 to operate it. Is there a way I can do this without using more ICs, such as ...
2
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1answer
44 views

SPI Flash memory programming with small buffer(uC memory)

I have AVR(or any, doesn't matter) microcontroller and 1 Megabyte SPI flash IC that I want to write to, I can do it already, have no problems with communication between these two. But so far I write ...
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0answers
20 views

Waverunner 610zi Serial decode

I'm using a LeeCroy WaveRunner 610zi to get the signals from a SPI flash, that contains the BIOS, and the CPU. The waveforms that I get are clean and the noise is acceptable. The WaveRunner has ...
1
vote
1answer
18 views

Touch sense controller interface

I am trying to implement a system where I have to use Touch Sense Controller(TSC) with LPC2138 controller, through SPI interface. As per my consideration, MOSI line of LPC2138 --> Din of TSC MISO ...
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0answers
31 views

STPM10 Based Energy Meter

I am working on a project which involves metering. For thsi purpose I am using single phase energy metering chip STPM10 from STMicroelectronics. I have successfully interfaced it with the ...
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vote
0answers
45 views

Connecting encoders/SPI devices/LEDs/buttons to a Rasperry Pi

I'm trying to connect a model B rev 2 Raspberry Pi to a whole bunch of stuff to create a MIDI foot controller: Adafruit touch screen 20 switches (some foot, some encoder buttons) 8 x SPI LED drivers ...
3
votes
2answers
294 views

Make Arduino and 89C52 talk to each other

I am trying to create a project in which I am required to make Arduino and Atmel 89C52 talk to each other. I know this can be achieved via UART but the problem is my Arduino is already using its ...
1
vote
1answer
73 views

U(S)ART/SPI/I2C - any common/prevalent/recommended connectors?

Good morning everyone! I'm currently building the board with the STM32F417 microcontroller, and I want to have separate (out-of-GPIO) I2C, SPI, UART and USART outputs on the board. But I'm lost on ...
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2answers
44 views

Understanding slow response of multiplexed thermocouples

I have a simple circuit swapping eight thermocouples through a MAX31855 analog-temperature-to-digital converter with two CD74HC4067 multiplexers. The MAX31855 is wired to the SPI pins on a raspberry ...
1
vote
0answers
56 views

Waveform decoding

I am trying to get the information from my mouse's optical sensor, strictly ΔX and ΔY. I looked up the datasheet for the microcontroller that communicates with the optical sensor and all I could find ...
2
votes
1answer
94 views

STM32F103 SPI Master example?

I want to use SPI master configuration and send some data just to capture it with Logic Analyzer. It seems that I cannot trigger on clock and capture anything. Using code from standard peripheral ...
0
votes
0answers
14 views

EINT ( Ext interrupt ) of LPC2138 is not getting low

I am using interrupt for touch sense TFT LCD application, where touching on LCD makes transition (on EINT pin) from high to low ( 3V to 0V ) and touch sense controller is through SPI interface to ...
0
votes
1answer
55 views

SPI Chip select queries [closed]

I have one query regarding SPI communication. I know in order to start communication, CS (Chip Select) signal needs to be asserted(high to Low) and in order to stop communication, CS needs to be ...
1
vote
0answers
91 views

spi fan out - sn74AHC244 - not working

I'm a complete beginner at this so please don't overlook any silly mistakes that a complete beginner may have made. I have a home-brewing project, where I am attempting to hook up multiple MAX31865 ...
1
vote
2answers
39 views

Why does the MCP4241 digital rheostat still work after Vdd is disconnected?

The MCP4241 digital rheostat still responds to SPI data after Vdd is disconnected. Could someone please shed some light on why that is? Data sheet: ...
0
votes
1answer
53 views

Mulitple open-circuit transmission lines

I'm using a single SPI microcontroller to talk to about 10 boards. Of course, only one of them is actively listening at a time, using chip select (for the unfamiliar, when chip select is high, the SPI ...
1
vote
0answers
29 views

Storing pulses, then releasing them on trigger

I have a BeagleBoneBlack microcontroller that can generate pulses and clock for SPI. These pulses have rise times of a few tens of nanoseconds, which is nice. Unforunately, the BeagleBone is ...
0
votes
0answers
24 views

RFM69HC Module Receive Error

I'm trying to control Hope RF's wireless module RFM69HC I'm setting all of the registers to receive and transmit messages. I'm using the device fixed payload length but what I've done the receiver ...
1
vote
0answers
47 views

Connecting 3.3V periperals with 3.3V or 5V MCU

I'd like to connect various 3.3V perpherals to works with either 3.3V (i.e. Arduino Due) or 5V MCU (i.e. Arduino Atmega2560). Here is a basic diagram: The system is consists of two parts: ...
0
votes
1answer
105 views

PIC24f: How to Generate Start condition using SPI for I2C device?

I am trying to communicate with the device having internal communication as I2C while externally it has two different pin for Input & Output along with a separate pin for Clock. Here is the link. ...
1
vote
0answers
46 views

ATmega328P SPI fails to transmit

G'day, I am currently experimenting with the an ATmega328P (on an Arduino, but programmed directly in C without the Arduino libraries) and it's SPI bus for communication with no other devices ...
-1
votes
1answer
47 views

transferring bytes of data continous using SPI

I am pretty new to SPI module. I need to write bytes of data at 3 different locations of the temperature sensor memory only one time after power up. My doubts is, can i write all data by asserting ...
0
votes
3answers
115 views

SPI Clock and CS signals

I have one doubt regarding SPI. I am very new to this module. I know that communication is initiated by asserting the CS(high to low) in SPI. And then in every clock based on polarity and phase the ...
3
votes
0answers
68 views

FSInit() - “CE_BAD_PARTITION”

I am using a PIC18F26K80 and an XC8 compiler. I am trying to initialise an SD card and create a file. I have simply formatted the SD card on Windows to have a "FAT32" file system and an "Allocation ...
1
vote
0answers
32 views

reading only 12-bits from SPI on MSP430F2122, is it possible?

I'm trying to read data from a RGB sensor (S9706) and I thought about using the SPI for the readings. The problem is that the sensor wants a little pause of 3-4us after each 12-bits (the colors ...
-3
votes
3answers
86 views

SPI- how does it work? [closed]

I am new to SPI. I am little bit confused about its working. I know that it is synchronous. Let's say I want to read a value at address. So the process would be: First master will send address byte. ...
1
vote
0answers
107 views

Send a file to an SD card over SPI

I am using a PIC18F4620 and an XC8 compiler. I am trying to create a file and send it to the SD card. I am using the MDD library from the MLA Legacy. My main is: ...
-4
votes
1answer
77 views

SPI - latch on trailing edge detail

I am asking in general about SPI. What does "Shift transmit data on the leading clock edge, latch on trailing edge" means? Does this means that data changes when Clock goes from High To Low. (This is ...
0
votes
1answer
83 views

Contiki: Serial Line IP via SPI

I am working on Contiki's cc2530 port (customizing for my custom radio). I do not unserstand how can i make SLIP work with SPI? I understand that SLIP is similar to UART (it is UART without parity, ...
0
votes
0answers
59 views

FSIO.c:8344: error: (1089) recursive function call to “_WriteFAT”

I am using a PIC18F25K80 and an XC8 compiler. I am currently trying to use the MDD library from the MLA legacy version (http://www.microchip.com/pagehandler/en-us/devtools/mla/legacy-mla.html). It was ...
0
votes
0answers
82 views

How to properly connect LCD 128x64 via SPI?

I'd like to share here some experience working with 186x64 graphic LCD while work in multiple-SPI device environment. I bought a 128x64 LCD on eBay. Manufacturer is unknown and it could be like ...
1
vote
1answer
96 views

SD card SPI interface for PIC18F25k80

I am using a PIC18f25k80 microprocessor and I want to transfer data on an SD card over SPI. The compiler I am using is MPLAB X XC8. Could you please provide an example of how I can initialise the SD ...
3
votes
3answers
226 views

Using I2C and SPI communication on the same same clock and data lines

I am using a PIC18F25K80 with multiple slave devices. All of them uses I2C except one. What i want to know is that can i first use I2C with the devives that uses I2C and then close I2C, change clock ...
0
votes
1answer
100 views

I2C-to-SPI bridge and SD card

I am using a PIC18F25k80 microprocessor, which is communicating by using I2C protocol with peripheral ICs. After collecting the data from the ICs I want to store them in an SD card. However for the SD ...
0
votes
2answers
108 views

How to correctly wire an interrupt pin, clock pin, PWM pin, SPI pin

I've a question about how to correctly wire some microcontrollers pins. In particular: Interrupt pin on microcontroller (pull up/pull down resistor and with which value) Output clock pin from a ...
0
votes
0answers
86 views

SPI Communication fails with ISO7241C but works with ISO7641FC, same circuit?

Objective: To interface DAC161S997, with Microcontroller C8051F350 through ISO7641FC using SPI Protocol, Which works fine and DAC output is achievable. Now here is the problem, I have changed ...
0
votes
1answer
73 views

Why does SPI flash has HOLD# pin, as opposed to stopping the clock?

A SPI flash like Micron M25P16 (shown below) has a HOLD# pin, and any input data is ignored if HOLD# is asserted at a rising clock edge. But can't the clock just be stopped instead ?
0
votes
0answers
23 views

Unable to access clock while interfacing AT32UC3C2512C with Flash Atmel Studio

I'm trying to interface the controller (AT32UC3C2512C) with flash using SPI protocol. The IDE that I'm using was Atmel Studio. I have written a simple code in which I'm trying to read the manufacturer ...
2
votes
0answers
101 views

SPI / SD Card communication issues

I am working with a PIC18F67K22 and am seeing some bizarre things in the SPI data stream. I am trying to interact with a FAT32 partition using FatFs and a custom built diskio.c file. I am able to ...