The 5V GPIO pin draws current through the Pi's main polyfuse from the PI's supply. So long as you don't have other USB or GPIO connected devices that make the total current potentially trip the polyfuse (ie. much >750mA) then an extra 60mA should be fine. (One of my GPIO test circuits drives an 8 x 8 array of LEDS drawing a similar total current, but on a model A Pi)yonubear wrote:hey question on the IR emitters can I pull the power from the 5v GPIO pin to run through the resister I plan to be limiting the current to each LED down to around 10ma as the spec sheet on the stick on emitters says 10ma. so I was trying to figure if I could safely pull the power from the 5v pin or do I need to split the incoming power from the ac adapter.
If the resistor wasn't necessary the designer wouldn't have put it in.yonubear wrote:... can I omit the base resistor or if not with this diagram how can I omit the base resistor the main reason is I am trying to make the PCb as small as possible and I am wiring 8 ir leds on 8 separate channels
If space is a premium go surface mount and change to eitheryonubear wrote:...but I suck at dealing with transistors can I omit the base resistor or if not with this diagram how can I omit the base resistor the main reason is I am trying to make the PCb as small as possible and I am wiring 8 ir leds on 8 separate channels.
Without knowing the transistor used and wired up correctly and exactly what the circuit you have made difficult to say.yonubear wrote:ok dumb question here I got it done however I am assuming I used to high of a resister on the base I used 1k 5%(what I had on hand) resister on the base which is fed to the GPIO pin and on the collector pin I used a 220ohm resister and I am unable to get any reaction from a led I am using a regular red Led for testing so that I have a visual check
oh and for a side note the size of the LEDs i use is irreverent for the size of my board as I am using external stick on emiters.
Those sorts of things happen to us all, when you have done many thousands of solder joints you still miss a few. Amount of times I have gone over a board to find a missing or bad joint is more than I would like to sayyonubear wrote:well power came back on and I found my issue I had not soldered the collector pin on the transistor so now that I feel totally stupid I just have to figure out why I get no reaction from the led when it comes on fine if I manually turn on the gpio pin.
Likewise. I've only tinkered with the "receiver side" of LIRC, but I was using a different GPIO input to that of the original blog.techpaul wrote:Sounds like configuration of irsend to use the correct GPIO pin not familiar with irsend myself
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# /etc/modules: kernel modules to load at boot time. # # This file contains the names of kernel modules that should be loaded # at boot time, one per line. Lines beginning with "#" are ignored. # Parameters can be specified after the module name. snd-bcm2835 i2c-dev lirc_dev lirc_rpi gpio_in_pin=23 gpio_out_pin=24