- Wed Apr 08, 2015 3:27 pm
#13904
A little update, I tweaked my circuit and code so that the GPIOs sink rather than source current and that seemed to have the desired effect, eliminating the glow during start up. Today however I noticed a bit of erratic behavior when I replaced one of the LEDs with a solid state relay and as with the LED, the gpio driving the relay would sink current through a 2.2Kohm resistor, I used the relay to switch an incandescent lamp, every once in a while at seeming random intervals, the lamp would flicker on and off. I'm not sure but it's possible this had been happening with the LED too and simply went unnoticed. Any thought on why this is happening?
- Fri Apr 17, 2015 4:59 pm
#14864
rocco, this just represents a boot up sequence of the MCU, you should probably only report this as an issue when they don’t turn on at startup. By tring to connect your GPIOs to a sink you effectively force them to stay low. It is always recommended to connect your GPIO with sinks so that the controller does not have to provide power to any LEDs or other components as such. It’s a serious design issue at times since controller can’t source a lot of current on multiple supplies.
electronics assembly
electronics assembly
Last edited by pedro on Thu Apr 23, 2015 12:03 pm, edited 1 time in total.
- Sun Apr 19, 2015 9:51 am
#15029
Any thoughts regarding my most recent post? In case it wasn't clear from the post, I am now using the GPIO's as sinks, that eliminated the original problem with the glowing leds at start up now I'm getting a flickering at random intervals well after start up. I'm hoping to use this circuit for a winch remote control, in that application any un-commanded activity is completely unacceptable, I've got to get this figured out before I can go any further.
