Tagged Questions

0
votes
3answers
63 views

Synchronizing SPI ports for higher data rate

I am designing a new board which uses the NXP LPC4330 (Cortex M4 microcontroller) with a XESS Xula2 FPGA development board. In this design, the Xula 2 has limited I/O pins since it is designed to fit ...
4
votes
2answers
105 views

How to deal with multiple pull-up resistors on modules

I was thinking about doing a modules for a development board I did a few days ago that will include spi/i2c interfaces. The problem is that I didn't included pull-up resistors in the MCU pins in the ...
5
votes
1answer
163 views

Serial Communication over 1 Pin?

Okay guys, I'm in a bit of a pickle here. I have the following circuit: As you can see, pin 3 is my only output. I've actually already had this board printed, so there's not much room for ...
0
votes
0answers
48 views

Are there any metastability issues with microcontroller SPI slave ports that can operate during sleep?

If one is using SPI to interface two microcontrollers that may spend much of their time sleeping, and if the SPI slave port is supposed to wake up its controller when data is received, that would ...
2
votes
3answers
200 views

Generation of text on composite video

I'm building a homebrew computer. I want some way to get video out, preferably along the lines of 80x25 text. I'm not interested in framebuffer graphics. Does such a thing exist as a single-chip text ...
1
vote
0answers
54 views

What's the best way to integrate SPI and MSC buses?

I have two chips. The first chip has only an SPI interface. The second chip has only an MSC (microsecond channel) interface. What's the best way to integrate them? Do you know any IC manufacturer ...
0
votes
0answers
212 views

STM32F4 + MCP4922 DAC + SPI + DMA = 0

I want to transmit data to MCP4922 DAC using SPI with DMA but as with most non-audio DACs it requires a pin toggle to latch data in the DAC buffers after each TX. There is a Chip select associated ...
7
votes
3answers
264 views

Routing 30MHz clock thru several boards

I'm using TLC5945 LED driver. Microcontroller (I'm using LPC1343) must provide a clock for it's internal PWM timer/counter. Maximum allowed clock speed is specified as 30MHz. I will have several ...
2
votes
1answer
224 views

SD card sector address vs. physical location

I'm curious as to how SD cards map the supplied sectors for read/write to physical locations in the flash memory. Is this the real physical address, or is it just a virtual address that the SD ...
0
votes
1answer
81 views

Keep SPI/TWI master active?

I'm designing a data recorder application which uses an 8-bit AVR microcontroller. It uses the TWI and SPI interfaces with the microcontroller being the master. There is one SPI device, a microSD ...
1
vote
0answers
396 views

PIC32 SPI ISR not being called when RXIF flag set?

I'm using a PIC32MX795F512L SPI3 module in slave mode. My master is sending data over the SPI line but my slave's interrupt service routine is never being called. The RX interrupt flag is being set ...
2
votes
3answers
379 views

Looking for a microcontroller for Audio DSP applications

I'm currently researching a system that has the ability to playback multiple sound files from an SD-card, add them together then output the signal to a DAC. I'm basically looking for specifications on ...
2
votes
3answers
407 views

What PIC microcontroller can interface with an ADXRS800 gyroscope with SPI output?

Straight to the point... I planning to use an ADXRS800 gyroscope and its output is a 32bit SPI message, does this mean that it can only be interfaced with a 32bit PIC microcontroller, or could i use ...
2
votes
2answers
666 views

Microcontroller with ADC and capable of SPI communication

I am designing a system where Analog Signal ---> (ADC- Digital Data )---> UWB chip mostly WSR601 or AL6301/AL5100 Chipset Note (1): UWB is an abbrieviation for Ultra Wide Band wireless ...
4
votes
1answer
828 views

Problems reading data from a microSD card

I am trying to read a block of data from a standard capacity micro SD card, but the received data does not make any sense. Here is what I'm doing: Initializing the card Reading data Setting CS low ...
1
vote
2answers
1k views

ADC sampling rate to MCU clock speed relationship

How can I determine the clock speed requirements of a mCU to manage a given ADC input? This application is very simple - I just want to take an SPI stream from an ADC into a mCU and spit it out the ...
2
votes
1answer
251 views

PIC24FJ64GB110 and 25AA160

I have a 25AA160 wired to a PIC24FJ64GB110 (100-pin): SO - RD3 (pin78) SI - RD2 (pin77) SCK - RD1 (pin76) SS is not used. CS\ is wired to GND and WP\, HOLD\ are wired to VDD. I copy/paste code ...
0
votes
4answers
594 views

Cheapest way to translate 5V SPI signal to 3V SPI?

I have a MCU that operates at 5V, and a display that recommends a 3V logic level. They are connected via SPI that can operate up to 1.5Mhz. What is the best way and the cheapest way (not necessarily ...
4
votes
3answers
335 views

What is wrong with this PIC pin change detection?

I have two PIC18F4620 connected via SPI + Slave Select + additional IRQ line. Both controllers are driven from the same crystal oscillator using the same clock settings. The master sends one byte and ...
4
votes
2answers
2k views

Is it possible to use 4-pin mode for an SD card with a microcontroller instead of SPI mode?

Is it possible to use the 4-pin mode of an SD card when designing an interface with a microcontroller, or must you always use SPI mode? I am particularly thinking of a microcontroller such as a PIC24. ...
3
votes
2answers
1k views

Any examples of an SPI based protocol with a checksum?

I have an application in mind in which I need to communicate via SPI with an FPGA. Both the FPGA and microcontroller are in our control, and so I have the flexibility to define the protocol as I see ...
22
votes
5answers
2k views

Programming microcontrollers: JTAG, SPI, USB oh my!?

I've noticed, with regards to microcontrollers, there are several way to program them. I am sorta familiar with USB as my Arduino's can be programmed via USB. What is a JTAG or SPI interface? ...