These are chat archives for esp8266/Arduino

6th
Aug 2016
Mehrdad K
@mkeyno
Aug 06 2016 15:17
hi guys , I've received Fatal exception 29(StoreProhibitedCause): , I defined pointer to function typedef void (*filelist)(); and use it in my loop() , is this error probably related to this pointer parameter
Mehrdad K
@mkeyno
Aug 06 2016 20:11
@forkineye do you have any suggestion to provide clean power for ESP8266 which is run 450 LED (APA104 by FastLED lib)
Shelby Merrick
@forkineye
Aug 06 2016 21:57
@mkeyno What are you using for a power supply? I typically use 12V 30A supplies for power, some decent capacitance at the module itself, then cascade 5V and 3.3V supplies, either switcher/LDO or LDO/LDO
an another 10uF smd cap and ferrite bead right by the ESP-01 header
Mehrdad K
@mkeyno
Aug 06 2016 22:00
I use 5v 40 A directly with 1000uf between power supply however my effect came with suddenly noise and glitch but when I put my finger on the ESP , its disappear, that's why I thought maybe my power not clean or maybe miss some low or high cap somewhere
Shelby Merrick
@forkineye
Aug 06 2016 22:04
well, touching it while running will definitely cause some issues. you have any ground loops? what module are you using or what does the board look like?
28703397941_6591ff5365_c.jpg
espixelstickv2.jpg
That's what I use to drive my pixels and the schematic for it
Mehrdad K
@mkeyno
Aug 06 2016 22:06
ground loops?
Shelby Merrick
@forkineye
Aug 06 2016 22:07
oh, are you saying the issues dissapear when you put your finger on it?
think i read your original post wrong
Mehrdad K
@mkeyno
Aug 06 2016 22:10
yes it is , but don't get your point what the ground loops is
Shelby Merrick
@forkineye
Aug 06 2016 22:11
Do you have multiple return points for ground?
how is it wired up and laid out?
28675321712_67e9961a3c_c.jpg
That's the same module fully assembled
Mehrdad K
@mkeyno
Aug 06 2016 22:12
07082016110.jpg
still don't know what return point is and why should make them ground
07082016111.jpg
my board is so simple and generic just pullup some pin and use pin 2 to run LED strip in size of 450 pixel
Shelby Merrick
@forkineye
Aug 06 2016 22:14
In that last pic, does your power come in on the right?
Mehrdad K
@mkeyno
Aug 06 2016 22:14
07082016112.jpg
yes the white socket
Shelby Merrick
@forkineye
Aug 06 2016 22:16
what regulator are you using?
Mehrdad K
@mkeyno
Aug 06 2016 22:17
LM1117
I might add in station mode the glitch is so less or even miss but in AP mode glitch happened frequently
Shelby Merrick
@forkineye
Aug 06 2016 22:21
In the last pic, the big cap is on input i take it? Are the other two paralleled on output?
Mehrdad K
@mkeyno
Aug 06 2016 22:22
no , the bigger one laid on 5 v pin and the smaller one laid on ESP 3.v pin
but I think it is useless
Shelby Merrick
@forkineye
Aug 06 2016 22:22
Make sure you're meeting the ESR requirements on the output of the LM1117. I've certain 1117's before that were very noisy if not. The datasheet for a TI LM1117 says the following:
8.2.2.1.3 Output Capacitor
The output capacitor is critical in maintaining regulator stability, and must meet the required conditions for both
minimum amount of capacitance and equivalent series resistance (ESR). The minimum output capacitance
required by the LM1117 is 10 µF, if a tantalum capacitor is used. Any increase of the output capacitance will
merely improve the loop stability and transient response. The ESR of the output capacitor should range between
0.3 Ω to 22 Ω. In the case of the adjustable regulator, when the CADJ is used, a larger output capacitance (22-µF
tantalum) is required.
Mehrdad K
@mkeyno
Aug 06 2016 22:24
I used 350 and 1000 uf
Shelby Merrick
@forkineye
Aug 06 2016 22:24
Capacitor ESR may be too high on your output. Is it a TI LM1117? Not all 1117's are the same
try putting a ceramic across the output of the 1117 as well and see if that helps
Mehrdad K
@mkeyno
Aug 06 2016 22:25
is it harmless to use higher cap ?
Shelby Merrick
@forkineye
Aug 06 2016 22:26
You can use larger capacitors, but large cheap electrolytics usally have much higher ESR
either 350 or 1000 would be complete overkill on the ouput of the regulator though. 10-22uF should be fine
Well, 10-100uF for that LM1117 it looks
and i've see some 1117's make noise with TOO low of an ESR on the output caps. some can be picky like that
Mehrdad K
@mkeyno
Aug 06 2016 22:29
you know , at first time use 100uf 16v but when I replace it with higher cap the result came better
Shelby Merrick
@forkineye
Aug 06 2016 22:30
For instance, I designed one board using On Semi's 1117's and tried a Diode Inc. 1117. The diode inc rippled like crazy whereas the On Semi was clean in same circuit.
Mehrdad K
@mkeyno
Aug 06 2016 22:30
how can I calculate ESR
Shelby Merrick
@forkineye
Aug 06 2016 22:30
It should be in the datsheet for your capacitors
Or you can measure it with an ESR meter
Mehrdad K
@mkeyno
Aug 06 2016 22:31
LED ESP01.pdf
this is the schematic
Shelby Merrick
@forkineye
Aug 06 2016 22:34
I'd start by checking the datasheets for your capacitors and LDO to make sure the ESR specs are met. Don't have a scope do you?
Mehrdad K
@mkeyno
Aug 06 2016 22:36
no , I've just use general schematic that other folks use , I'm not pro in electronic buddy