Interfacing using ULN2003A - Raspberry Pi Forums

-

so quite new pi , have general understanding of coding , computing...but electronics can struggle (although gcse electronics got in 10 years go has come in handy!).

use gpio pins (3.3v...low current allowance) of pi b v2 power various larger more current hungry devices (relays in case start with).

after doing bit of reading , coming across sainsmart relay boards, got 1 , few resistors , transistors in order make simple interface board. 1 problem

a) relay board not seem power on... on connecting 5v 8pin vcc , gnd gnd 8pin, no relays click (meant active low). no leds light either.

b) interface board ugly mess of resistor, ribbon cable , transistor.

did little more searching potential "better solution".

ul2003a chips (7 darlington arrays) allow 50v output, 500ma per driver; giving interface relay board on single chip!

http://www.usefulcomponents.com/ebay/pi ... 03a_st.pdf

wired 1 up?

search relay and/or uln and/or sainsmart , you'll multiple hits. if lucky you'll find example particular board.


raspberrypi



Comments

Post a Comment

Popular posts from this blog

Thread: PKI Client 5.00 install (for eToken Pro)

-
my company uses aladdin etoken pro authentication on vpn connections. etoken requires pki client application on client machine before os recognize it. app , token work fine on xp, use ubuntu on laptop. aladdin has offered linux version of client, rpm. convinced our internal guys rpms, , i've been trying work couple days. begin with, hp pavilion dv4-1435dx laptop running jaunty 64-bit. - started out converting .rpm .deb using alien: code: sudo alien -d pkiclient-5.00.28-0.x86_64.rpm - worked fine , got nice little .deb - next, ran .deb install client: code: sudo dpkg -i pkiclient_5.00.28-1_amd64.deb - , executed without errors/issues. pdf rpm said there should launcher @ applications > etoken > start etoken pki client, didn't exist. figured might because installed deb instead of rpm. bounced box, still wasn't there. no big deal... - install network manager can configure vpn connection use token: code: sudo aptit...
Read more

ATmega2560-Arduino Pin Mapping

-
hi community, in last days working on project using arduino mega 2560. on planning pin using found bugs in atmega2560-arduino pin mapping . if right there labels (such pwm) in 'mapped pin name' @ wrong row ( mixed pin numbers right one...) in attachment openoffice calc , pdf file corrected table. ( hope ;-) ) i post here tab separated table : code: [select] arduino mega 2560 pin mapping table atmega 2560 pin out arduino mega function nr name function function function mapped pin name function function datasheet 1 pg5 oc0b digital pin 04 pwm 2 pe0 rxd0 pcint8 digital pin 00 rx0 (usart0 receive pin, programming data input or pin change interrupt 8) 3 pe1 txd0 digital pin 01 tx0 (usart0 transmit pin or programming data output) 4 pe2 xck0 ain0 (usart0 external clock  input/output) 5 pe3 oc3a ain1 digital pin 05 pwm 6 pe4 ...
Read more

Crossfader Arduino Tutorial

-
hello i'm super newb please don't bash me much. i'm using led's , i've connected them correctly (finally) , wondering why program here ( http://www.arduino.cc/en/tutorial/colorcrossfader ) doesn't work? say's haven't declared crossfade. read directions on top , said crossfade needs used list order of colors. isn't declared in main part (void loop() )? or need declared before? nevermind void on bottom , needed before voidloop. lol anyways playing rgb led's wondering if has specific way of making them fade in , out different colors? (brightness , color mixing) code: [select] /* * code cross-fading 3 leds, red, green , blue (rgb) * create fades, need 2 things: *  1. describe colors want displayed *  2. list order want them fade in * * describing color: * color array of 3 percentages, 0-100, *  controlling red, green , blue leds * * red red led @ full, blue , green off *   int red = { 100, 0, 0 } * dim white 3 l...
Read more