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 ...

learn more… | top users | synonyms

0
votes
2answers
36 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
47 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 ...
1
vote
1answer
50 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
10 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
41 views

SPI Chip select queries

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
74 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 ...
0
votes
0answers
74 views

Digital Potentiometer and Motor Speed Controller [migrated]

I'm trying to get a Chinese 20A DC Motor Speed Controller working with a MCP42100 Digital Potentiometer. The analogue potentiometer supplied was 100kOhm. I have programmed my arduino with the ...
1
vote
2answers
38 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
47 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
27 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
13 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
40 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
92 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
38 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
2answers
87 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
63 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
19 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
76 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
93 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
71 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
59 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
45 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
57 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 ...
0
votes
1answer
76 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
179 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
70 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
101 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
81 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
58 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
22 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
91 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 ...
0
votes
0answers
23 views

Max RF Chip SPI speed LT8900

I'm using an LT8900 chip for RF communication. I can not use the chip on a high speed and only on Maximum of 2Mhz. The datasheets say "CLK frequency range (SPI) FSPI 12 MHz" so why don't I see ...
1
vote
1answer
183 views

How to write 4 bytes continuous data without any SCK delay through SPI with Pic18f45k20

In pic18f45k20, I have to write 4byte data at once without any setup SCK delay through SPI. Is there any way to cancel the SCK delay while sending 4 bytes together?(like Assembly)I am using MPLAB-XC8 ...
1
vote
2answers
78 views

Problem with SPI communication when Silabs Si86xx digital isolator is used

I'm trying to establish communication between Atmel Atmega32U4 (used in Arduino Leonardo) on MCU PCB and TI DAC8552 on PSU PCB via isolated SPI link. For isolation I'm using Silicon Labs Si86xx ...
0
votes
1answer
51 views

Informations about FT2232H as programmer

I was looking on a EVB that use FT2232H chip to program an SPI ram used in second time to programm another device. My question is, if I copy the circuit that programm this SPI ram and use the same ...
0
votes
1answer
130 views

MISO/MOSI vs DI/DO

Is there a difference between the MISO/MOSI pins and the DI/DO pins? Is it true that MISO/MOSI is for SPI communication where DI/DO is for USI communication? What is the difference exactly?
0
votes
0answers
40 views

Using SPORT for SPI

I'm using Analog's Blackfin (BF-532) for sensing and wireless transmission. Both my sensors and radios use the SPI interface. However, since I need the two devices operate at different frequency, I ...
0
votes
1answer
95 views

In a Lattice MachXO2, how can I use the EFB SPI slave and configuration SSPI (multiplexing)?

I am using a Lattice MachXO2 FPGA eval board and Lattice Diamond 3.4.0.80 on Linux. I want to use the configuration SSPI to update the FPGA configuration. During user mode, I want to use the same ...
1
vote
2answers
58 views

does SPI master always receive data in same time he send data

I try to communicate with EPPROM using SPI. the image illustrate the read status register sequence. the program I'm using checks the receive data register each time SPI finish sending (send data ...
0
votes
1answer
40 views

What does Limit at Min to Max values in datasheet means?

I have doubt while implementing I/O SPI interface for the ADF4158 PLL Synthesizer. I planned to use a simple I/O model to send bytes (using only 3 bits for 3 lines) using RS232 at 115200 BPS. I didn't ...
0
votes
1answer
59 views

SPI Communication during Programming

I am using the ATtiny861a and have made it so that the SPI connects to a Radio and an external memory source VIA two different chip select pins but sharing the same MISO/MOSI/CLK line. Correct me if ...
2
votes
2answers
121 views

read sd without filesystem [closed]

I design a DAQ to collect data from different sensor. The data are write in an SD Card by a microcontroller dsPIC33FJ256GP710A. The data are stored without a file system for speed reason. Now I need ...
0
votes
1answer
112 views

VHDL SPI xilinx spartan 3E

I have nearly non previous experience with VHDL and the most of the code here is given to me by the teacher. I'm trying to communicate with a ADXL362 accelerometer using SPI on a Xilinx Sparten 3E. ...
0
votes
1answer
58 views

CS/SS pin configuration

I am using an ATtiny861a and I want to enable it to use SPI. In doing this I need to assign not one, but two CS/SS pins in order to communicate with a radio and an external memory. Does the CS/SS pin ...
3
votes
1answer
54 views

What is holding the SS pin high in SPI master mode on AVRs?

A typical AVR datasheet contains the following example of an SPI Master mode configuration (here from page 164 of the ATmega128/L datasheet): ...
0
votes
1answer
74 views

SPI communication with multiple slaves

I am working on a project that is using an ATtiny861A and this only has one SPI. If I want to hook up a radio and an external memory to the same SPI, will there be an issue sending data from the ...
0
votes
1answer
38 views

S25FL032P NOR Flash interfacing over SPI Bit Banging

I am working with a NOR Flash memory chip: S25FL032P manufactured by Spansion. I am interfacing the NOR Flash over SPI by Bit Banging as I am going to use the dedicated SPI engine for some other ...
0
votes
0answers
53 views

SPI Flash Filesystem

I'm currently working on a portable product (microcontroller is the STM32F429) and store a lot of readings into a 128Mbit SPI flash (M25P128 from Micron). Essentially, I'm storing about 10 bytes or so ...
2
votes
3answers
125 views

I2C and SPI on the same bus

I have already configured an I2C protocol between a master device (PIC) and two slave devices (sensor ICs). After obtaining the measurements from the sensors I want to store them on an SD card. For ...