Latches: What Are They For?

Started by Fao, Sean in comp.arch.embedded14 years ago 12 replies

I'm just starting to get into embedded systems and I recently stumbled across latches (as well as flip-flops). But I don't understand what...

I'm just starting to get into embedded systems and I recently stumbled across latches (as well as flip-flops). But I don't understand what they're used for. First, if you would please clarify that I understand how they work, I'd greatly appreciate it. It is my understanding that I'd usually set the bits (in my case, seven bits for a 7-segment LED display) on my microcontroller first...


which 8-bit micro

Started by Kim in comp.arch.embedded16 years ago 23 replies

I'm need a micro with following requirements: UART - RS485 inputs = 4 outputs = 4 Also need to drive a seven segment LED or dot matrix. Its...

I'm need a micro with following requirements: UART - RS485 inputs = 4 outputs = 4 Also need to drive a seven segment LED or dot matrix. Its for an remote operator station and the quantity is quite small, but may go to 1000 units over time. Its been awhile since my last project, so I'm not sure whats available today. Would prefer an "all-on-board" chip if possible. Cost is a considera...


Explanation of the whole 300 mA thing

Started by in comp.arch.embedded12 years ago 11 replies

Firstly, I'd like to thank all the people who've help me out so far that contributed to the "300 mA" thread. I'm doing an embedded...

Firstly, I'd like to thank all the people who've help me out so far that contributed to the "300 mA" thread. I'm doing an embedded systems project for college, I'm a 3rd year doing Electronic Engineering. It's a Connect4 game consisting of 42 LEDs (6 rows, 7 columns). Each LED can be either Red, Green or Off. At the end of this post, I have a link to a PDF of the current ...


Inexpensive

Started by larwe in comp.arch.embedded10 years ago 3 replies

I'm building a little toy, and need to read a hand-encoded storage medium something like punched tape. Right now I'm looking at the Panasonic...

I'm building a little toy, and need to read a hand-encoded storage medium something like punched tape. Right now I'm looking at the Panasonic CNB1002 reflective photosensors, which integrate an IR LED and phototransistor in a small gull-wing SMD package. In my small quantities they're about $0.55 each. I need three - a clock bit, and two data channels. Apart from the cost they're perfect - th...


Cheap Microcontrollers

Started by Zach_G in comp.arch.embedded12 years ago 29 replies

Hello there, I'm looking for a very cheap microcontroller indeed. Price point is under 0.35 USD, quantities of 50-100k for first production...

Hello there, I'm looking for a very cheap microcontroller indeed. Price point is under 0.35 USD, quantities of 50-100k for first production runs. Application is an RGB LED controller that accepts color information over asynchronous serial communication. I crammed that in an attiny11 pretty easily, but Atmel is discontinuing that model and replacing it with the 2-3X as expensive attiny13! While i...


Connect4: It all works perfectly

Started by in comp.arch.embedded12 years ago 1 reply

You may recall I've posted here in the last couple of months about my college project, which was to make a Connect4 game using 42 LED's, doing...

You may recall I've posted here in the last couple of months about my college project, which was to make a Connect4 game using 42 LED's, doing display multiplexing so that only one column is lit at a time. I had a very funky shift-register setup in which I used two precisely- timed RC circuits so that I'd only need one microcontroller pin to control the shifting. The theory was sound, but...


n00b question

Started by jam4ar in comp.arch.embedded14 years ago 5 replies

Hello, I'm reading "Microcontroller Projects in C for the 8051" by Dogan Ibrahim and I have a question that I can't find the answer to in...

Hello, I'm reading "Microcontroller Projects in C for the 8051" by Dogan Ibrahim and I have a question that I can't find the answer to in the text nor anywhere else that I've searched. When driving an LED from a pin, he says the port is in "current source mode", and when using the pin to produce a tone with a small speaker connected to a n channel MOSFET, he says the output is in "Voltag...


PALCE & GAL Devices

Started by partis in comp.arch.embedded14 years ago 5 replies

I have been led to believe tha PALCE devices are fuse (and everything else!) compatable with GAL devices. Is this correct? More...

I have been led to believe tha PALCE devices are fuse (and everything else!) compatable with GAL devices. Is this correct? More specifically, can a JEDEC file aimed at a Cypress PALCE20V8 be programmed into a Lattice GAL20V8 without modification? Thanks in advance, Gary Partis


Could somebody read out a GAL20V8 for me? (or measure it)

Started by Anonymous in comp.arch.embedded16 years ago 4 replies
LED

Need to read out the content of a GAL20V8. It does not use any FF's. It contains pure combination logic. I know a bunch of LED's and some...

Need to read out the content of a GAL20V8. It does not use any FF's. It contains pure combination logic. I know a bunch of LED's and some jumpers can do the job, but I am out of resources and this simple goal will cost me a lot of time. Could somebody in the group generously help me to measure it? If you have a proper device this will be fairly easy. I can pay shipping both way. Thank you. ...


Z8 encore GPIO

Started by Cass in comp.arch.embedded15 years ago 1 reply

Please excuse my ignorance. I just bought the 39.95 Z86423 Encore MCU package. This is the unit that only has three leds (one red, one yellow,...

Please excuse my ignorance. I just bought the 39.95 Z86423 Encore MCU package. This is the unit that only has three leds (one red, one yellow, and one green) instead of the led matrix array. I have gotten the serial port to work and can see printfs, but I would like to play with the GPIO ports. However, it seems that these ports are connected to holes in the PCB. As far as I can tell, th...


PPC405 sleep?

Started by Bo in comp.arch.embedded15 years ago 6 replies

I am trying to put the PPC405 asleep on a VirtexIIPro ML310 Xilinx development board and not have a lot of luck. I'm running VxWorks and have...

I am trying to put the PPC405 asleep on a VirtexIIPro ML310 Xilinx development board and not have a lot of luck. I'm running VxWorks and have written a little application that toggles an LED so that I know the task is running. I've tried two methods--with drastically different results-- but neither of which do everything I need. First try: I loaded my app that toggles LEDs via a Tor...


IR network for PIC-processors

Started by Kristoffer Ek in comp.arch.embedded8 years ago 16 replies

Hi, I have built timer/controllers for 10 kodak dias caroussels with a pic18f2550 microcontroller, and I want them to communicate to each...

Hi, I have built timer/controllers for 10 kodak dias caroussels with a pic18f2550 microcontroller, and I want them to communicate to each other. Therefore I put a IR-LED and a IR-receiver on the pic's serial port and want to build some kind of ir protocol to broadcast settings over the network. All caroussels can not "see" all the other ones, so each caroussel has to retransmit received...


Source of custom segmented OLED display

Started by John Speth in comp.arch.embedded16 years ago 2 replies
LED

Can anyone point me to a company that can produce custom segmented OLED displays? (OLED = organic LED) My internet search turns up very...

Can anyone point me to a company that can produce custom segmented OLED displays? (OLED = organic LED) My internet search turns up very little information. I wonder if the technolgy isn't quite mature enough for my needs. Thanks... John Speth mailto:johnspeth@yahoo.com


Q:Help with Microcontroller selction

Started by Andreas Schweiger in comp.arch.embedded12 years ago 18 replies

Hi All, i am looking for a new Micro for a private project: Needed Features: - Performance of a 12MHz 80C535 is enough - 2 serial...

Hi All, i am looking for a new Micro for a private project: Needed Features: - Performance of a 12MHz 80C535 is enough - 2 serial Ports - 128kB Flash - Battery bufferd SRAM on board (16k and more) - RTC - 4 8 or 16bit Timers - GPIO's for Key's (8), LCD (Standart 4 bit and control) and LED (8) - SD card interface Most cruical is that a free compiler is available since I dont want...


Embedded Video module

Started by Don in comp.arch.embedded14 years ago 3 replies

Hi All, I am looking for recommendations for an embedded video module which I can talk to with an 8 bit MPU (AVR). I need to be able to...

Hi All, I am looking for recommendations for an embedded video module which I can talk to with an 8 bit MPU (AVR). I need to be able to control the electronic shutter to grab a frame at a particular instant. Lighting varies but is reasonably controlled by LED's. Resolution needs to be 640x480 monochrome or better. Camera can be integral or seperate. Communication can be serial or pa...


alarm clock

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

hello i'm a quite newby to embedded systems and have some basic questions to you. i'd like to build up a alarm clock which has some special...

hello i'm a quite newby to embedded systems and have some basic questions to you. i'd like to build up a alarm clock which has some special features as: - radio controlled - LED projection on wall/ceiling - fully customizeable awake times (this is the main reason), eg. mo, fri, 14.4.2007 ..... of course the clock needs to have a display with backlight (on keypress) sounds like a ...


Small processor selection

Started by AssemblyZig in comp.arch.embedded14 years ago 6 replies

My apologies if this topic has been beaten to a pulp, but my casual search has not yet led me to the answers I need. We have developed a small...

My apologies if this topic has been beaten to a pulp, but my casual search has not yet led me to the answers I need. We have developed a small system based on the redoubtable Cygnal/SILabs C8051F311 processor. While all of the current functionality fits into the 16 KBytes of onboard FLASH, it's tight, and we are just one validated feature request from being out of luck. As a result, I'm...


Interference with Max7219

Started by Anonymous in comp.arch.embedded14 years ago 5 replies

Hi - I've built some 16x16 LED displays using four Max7219 seven-segment drivers (each can multiplex an 8x8 array). I use a Rabbit micro...

Hi - I've built some 16x16 LED displays using four Max7219 seven-segment drivers (each can multiplex an 8x8 array). I use a Rabbit micro to update the 7219's, enabling me to show lo-res video. The problem I'm having is that intermittantly one or more of the 8x8 quadrants goes blank, while the rest of the display continues to work correctly. It works better in some locations than others. I'...


Source for Electronic Hour Meters

Started by Anton Erasmus in comp.arch.embedded16 years ago 3 replies

Hi, I am looking for a source of small rugged electronic hour meters. Something with an LCD or LED display. Regards Anton Erasmus

Hi, I am looking for a source of small rugged electronic hour meters. Something with an LCD or LED display. Regards Anton Erasmus


How: microcontrolled 0-12V 1A output

Started by andrew queisser in comp.arch.embedded16 years ago 1 reply

I'd like to have my microcontroller (8051) control a 0-12V DC output voltage with up to 1A. It doesn't have to be accurate (e.g. 8bit is enough)...

I'd like to have my microcontroller (8051) control a 0-12V DC output voltage with up to 1A. It doesn't have to be accurate (e.g. 8bit is enough) and it doesn't have to be very clean - it's for an LED illuminator controller. I know I could use a linear regulator and an D/A converter or a digital potentiometer but I'm wondering if it would be better to use a switching regulator so I don't ...