generating ntsc video

Started by Jacek Mazurkiewicz in comp.arch.embedded15 years ago 10 replies

Can anyone give me an idea as to the bare minimum system requirements for generating the picture information for some NTSC video at a very...

Can anyone give me an idea as to the bare minimum system requirements for generating the picture information for some NTSC video at a very low resolution? I'll be working with a small 8085 microcontroller for which I don't yet have the exact specifications (it either operates at a 1KHz or 1MHz clock speed), and I was wondering if I could somehow use this to generate a composite video sig...


I2C - distance between master and slave?

Started by Jens Gydesen in comp.arch.embedded13 years ago 13 replies

Hi what is your experience with the I2C bus, what is the practical max distance, please specify your pull-up resistor value, I2C clock...

Hi what is your experience with the I2C bus, what is the practical max distance, please specify your pull-up resistor value, I2C clock speed, and distance thank you, best regards Jens -------------------------------------------------------------------------------- Jeg beskyttes af den gratis SPAMfighter til privatbrugere. Den har indtil videre sparet mig for at f? 3924 spa...


CAN-settings for PIC18F4585

Started by Mich in comp.arch.embedded12 years ago 2 replies

Hi, I 'm programming a PIC18F4585 with MPLAB. I want to use the CAN option and I have made the basic C and H files with the aplication maestro...

Hi, I 'm programming a PIC18F4585 with MPLAB. I want to use the CAN option and I have made the basic C and H files with the aplication maestro of Microchip. I 'm working on a clock frequency of 40MHz. These are the settings I have calculated for a baudrate of 125k. #define BAUD_RATE_PRESC 16 #define SJW_TIME 1 #define SAMPLES 1 #define PROP_TIME 2 #define PH_SEG_1 4 #define PH_SEG...


Soft ARM in an FPGA

Started by arm_newbie in comp.arch.embedded11 years ago

I'm trying to understand what the advantage of putting a soft implementation of an ARM in an FPGA (Altera or Xilinx) is. The reason I ask is both...

I'm trying to understand what the advantage of putting a soft implementation of an ARM in an FPGA (Altera or Xilinx) is. The reason I ask is both of them have entirely adequate 32-bit soft processors of their own. Each has a nice development environment with lots of IP, growing ecosystems, and will run easily 3x to 4x the clock speed of the soft ARM. I suspect it has something to do with "indus...


FTDI4232H & DAC problem

Started by averwind in comp.arch.embedded7 years ago

Earlier I was able to interface with a ADC (ADS7871) using the SPI interface provided by FTDI. It was really a struggle but that it is...

Earlier I was able to interface with a ADC (ADS7871) using the SPI interface provided by FTDI. It was really a struggle but that it is working quite good now. Now I am trying to interface with a DAC which is AD5420AREZ from Analog Devices ( http://www.analog.com/static/imported-files/data_sheets/AD5410_5420.pdf ). The pin assignments are as follows: ADBUS0 -> SK = Serial Clock - Connect to A


ATXmega16A4U runs happily at 64 Mhz

Started by Jim Stewart in comp.arch.embedded7 years ago 7 replies

Although I don't believe in shipping products with parts pushed past their datasheet specs, I'm not above playing around. After a day...

Although I don't believe in shipping products with parts pushed past their datasheet specs, I'm not above playing around. After a day of figuring out the clock and pll on the above chip and getting the pll to run at 64 Mhz, I thought "what the hell" and changed the cpu divider from 2 to 1. The part runs just fine and a scope verified that it is indeed running at 64 Mhz. Not bad for a $1...


lf: oem embedded controller ...

Started by Anonymous in comp.arch.embedded11 years ago

As a software guy, I'm looking for an OEM type controller suitable for an industrial setting that just needs to have programming added ......

As a software guy, I'm looking for an OEM type controller suitable for an industrial setting that just needs to have programming added ... preferably an out of box solution with RTOS, a couple of relays, RT clock and some sort of simple user interface (touch screen/buttons whatever) ready to go, with protective enclosure and dev kit ... (C or Forth preferred). required: user i...


I2C troubleshooting

Started by Patrick M in comp.arch.embedded14 years ago 4 replies

Greetings, I'm currently facing a weird problem trying to have a i2c master and several slaves communicate... The slave will only send an...

Greetings, I'm currently facing a weird problem trying to have a i2c master and several slaves communicate... The slave will only send an acknowledge back to the master if the data and clock signals have probes on them. The probes have a 1 M-ohm resistance... As soon as I take the probes off, the master never receives an acknowledge... Any pointer or tip on how to debug this would be ...


EZUSB FX2LP communication spped

Started by Anonymous in comp.arch.embedded13 years ago

Hi out there, I am trying to build a device that reads data for a error measurements as fast as possible. I want to read data from the FX2s...

Hi out there, I am trying to build a device that reads data for a error measurements as fast as possible. I want to read data from the FX2s GPIF and send it to a host PC. Now I have my first test hardware an I am able to transfer data with app. 2,5 MB/s using endpoint 6 with 512 Byte packet size and double buffering. I read data with an external clock of 40 MHz. Data packets are sent by th...


EZUSB FX2LP communication speed

Started by Anonymous in comp.arch.embedded13 years ago 2 replies

Hi out there, I am trying to build a device that reads data for a error measurements as fast as possible. I want to read data from the FX2s...

Hi out there, I am trying to build a device that reads data for a error measurements as fast as possible. I want to read data from the FX2s GPIF and send it to a host PC. Now I have my first test hardware an I am able to transfer data with app. 2,5 MB/s using endpoint 6 with 512 Byte packet size and double buffering. I read data with an external clock of 40 MHz. Data packets are sent by th...


Using different numbers of TQ but same frequency on CAN bus?

Started by Mike Noone in comp.arch.embedded13 years ago 2 replies

Hi - I have a system that consists of one Atmel SAM7X256 connected via CAN to 6 Microchip MCP2515 chips. The MCP2515s have 20MHz clocks, and the...

Hi - I have a system that consists of one Atmel SAM7X256 connected via CAN to 6 Microchip MCP2515 chips. The MCP2515s have 20MHz clocks, and the SAM7X256 has a 55MHz clock. I have the CAN bus running at 1MHz right now, but the chips aren't perfectly matched. Specifically, the SAM7X256 uses 11TQ, while the MCP2515 uses 10TQ. I had to do this as otherwise I'd have to have fractional baudrate di...


DSS Interface

Started by rickman in comp.arch.embedded9 years ago 2 replies

We happen to be doing an upgrade to an existing card I am selling a customer and they are asking about the feasibility of providing a...

We happen to be doing an upgrade to an existing card I am selling a customer and they are asking about the feasibility of providing a DSS interface (56 kbps AMI encoding). Their thought was to use the audio I/O which has very strong differential drivers with an output impedance of 50 ohms. We can boost the sample rate up to 212 ksps, but with a fixed sample rate. To extract the clock would...


pic16f627 with different baudrates

Started by rose fay in comp.arch.embedded12 years ago 2 replies

Hi! I am a newbee of using PIC USART and internal clock. I am developing a program that will send a data to an instrument to enable it to...

Hi! I am a newbee of using PIC USART and internal clock. I am developing a program that will send a data to an instrument to enable it to send an output to the PC via RS232. The problem is, my hardware has 8 channels with different instruments which run with different baudrates. The data sent is similar on all channels. How could i send the correct data to the corresponding channel which i...


ADIS16405 IMU data reading

Started by Mamidipalli in comp.arch.embedded9 years ago 1 reply

hi ..... We are using ADIS 16405 IMU from Analog Devices in our application,we are using SPI interface for collecting the data from IMU.We...

hi ..... We are using ADIS 16405 IMU from Analog Devices in our application,we are using SPI interface for collecting the data from IMU.We are able to get the correct data but once in a while data shows 0x0000. Earlier we thought that it might be the problem with power glitches and used regulated 5v dc source but still the same problem is coming.we are operating the device with clock rat...


Designing the right clock tree for a multi-FPGA setup

Started by Geronimo Stempovski in comp.arch.embedded12 years ago 2 replies

Hi folks, I am planning to design a PCB featuring three Virtex-4 FX60 FPGAs and some periphery. The three FPGAs are needed due to the data...

Hi folks, I am planning to design a PCB featuring three Virtex-4 FX60 FPGAs and some periphery. The three FPGAs are needed due to the data processing complexity and the amount of high-speed IOs (MGTs). What I am most concerned about right now is to find an appropriate clocking solution. In my opinion, there are mainly three alternatives to design the clocking scheme: a) connection...


STR912 RTC Crystal

Started by amerdsp in comp.arch.embedded12 years ago 2 replies

Hello, I am trying to use a surface mount crystal for the RTC clock on the STR912F microcontroller. The datasheet states that the...

Hello, I am trying to use a surface mount crystal for the RTC clock on the STR912F microcontroller. The datasheet states that the load capacitance is 8pF (Typ). Unfortunately, I am unable to find an SMD crystal with that load capacitance. I can, however, find 7pF and 9pF. Can they be used? Any hints or ideas? Thank you, A


msp430 for low power application

Started by cellmania in comp.arch.embedded11 years ago 12 replies

i am working on a project on wireless sensors....i need a processor where the clock frequency can be varied during RUN-TIME so as use in...

i am working on a project on wireless sensors....i need a processor where the clock frequency can be varied during RUN-TIME so as use in low-power applications....but it must not be as low as is the case in the sleep mode. i found that the option of variable frequency is not available in avr controllers on which i have worked on till now...i was thinking about msp430 series but i cannot find a ...


MSP430 vs Au1100 Alchemy - the GPIO battle

Started by Anonymous in comp.arch.embedded12 years ago 4 replies

Hello, When I toggle a GPIO on my MSP430 processor I have (or at least I think I have :) a clean understanding of what happens. I can...

Hello, When I toggle a GPIO on my MSP430 processor I have (or at least I think I have :) a clean understanding of what happens. I can relate the frequency of the toggling to the instructions used and the clock speed of the CPU. Nothing strange happens. The MSP430 runs the instructions below: /* Put 0xAA in the r15 register. */ mov.b #-86, r15 /* Write the contents of r15 on p...


Accessing general I/O addresses

Started by ssylee in comp.arch.embedded12 years ago 10 replies

I apologize in advance if I didn't cross-post properly. I want to write a .c and .h file controlling a DS1302 real-time clock using a PIC18F2620...

I apologize in advance if I didn't cross-post properly. I want to write a .c and .h file controlling a DS1302 real-time clock using a PIC18F2620 microcontroller. I want to keep my RTC code's pin usage flexible, so I want to write an initialization routine that reads in the pins that the whole program wants to use in main.c and have RTC.c and RTC.h refer to the wanted pins. I am having trouble...


Clock problems with SSC on AT91SAM7S64

Started by Count Down in comp.arch.embedded14 years ago 1 reply

I'm trying to use the Synchronous Serial Controller (SSC) on the Atme AT91SAM7S64 development kit (AT91SAM7S-EK) to interface with a...

I'm trying to use the Synchronous Serial Controller (SSC) on the Atme AT91SAM7S64 development kit (AT91SAM7S-EK) to interface with a Nordi nRF2401 radio transceiver. The Atmel documentatio (6175A-ATARM-13-Jul-05, page 352) indicates that the SSC's transmit cloc can "drive the TK I/O pad continuously or be limited to the actual dat transfer." However, the options for controlling the output o...