modlesjust dont get it
cehtehhow much current does the 'enable' sink?
cehtehand is the gps connected to the 5v out of the arduino?
modlesim not sure, cant see it in the dataasheet
modlesgps is connected to the 3.3v output of the arduino yes
modlesits an ardunio pro mini
modlesdatasheet just says enable pin High active, or keep floating for normal working
cehtehthe 3v3 pin cant provide much current
pwillard" keep floating for normal working" sounds 'suspect'...
cehtehand is the enable pin 5V tolerant?
modlesits a 3.3v arduino so shouldnt matter
cehtehif not then there is a protection diode
cehtehah ok
cehtehthought 5V
modlesi dont get why the enable pin would pull any significant current
cehtehmeasure it
modlesok 2 secs
cehtehmaybe (likely) not the pin
cehtehbut the gps may draw some power when turning on
cehtehmeasure that too
cehtehcould be too much for the punny 3v3 regulator
modlesenable pin draws 0ma, so tiny.
modlesi.e too small for my mA reader to see
pwillardwhat is the power supply rated for?
cehtehlipo he saied
modleswhats weird is that if I manually plug the enable pin into the 3v3 output of arduino, its enables it fine
cehtehdouble check your conections i bet you made some error
modlesi dont have anything else running on the 3v3 output, so the load is low
pwillardso it pulls too much current from the pin.
modlesits such a simple circuit, i cant see what i could have got wrong
cehtehdouble check
cehtehits not working, so there must be some error
modlesok so if i hook up the IO pin to the enable pin via a mA meter, the needle doesnt move when the pin is set to HIGH
modlesyet the arduino resets
modlesmaybe it isnt a brown out
cehtehdebugging ftw
modleshow can i check that?
cehtehyou just have some crappy software bug :)
cehtehcheck your code
modlespinMode(pin_GPSenable, OUTPUT); digitalWrite(pin_GPSenable, HIGH);
modlesdoesnt get much simpler than that
cehtehand after that?
cehtehand do you set pinmode in loop not in setup?
modlesi put it in setup
pwillardFYI: The datasheet already SHOWS the enable pin pulled HIGH
cehtehthen how does your loop look?
modlesafter the HiGH call ive just put a long delay
cehtehand how did you determine its browned out?
modlesso do i need to use a FET or something to pull it low?
pwillardso the only thing you ever want to do is pull LOW to disable
modlesyeah but what the opposite of LOW?
modlesis there a NULL?
pwillardit has an internal pullup
modlesi.e i pull low to disable, but how do i enable
cehtehdo you want the gps always on?
modlesi want to be able to turn it on and off
pwillardthen use a 2n7000 to pull low
cehtehthen you have to digitalWrite(pin_GPSenable, LOW ); to turn it off
modlescehteh: sure, but how do i turn it back on?
pwillardstop pulling it LOW
cehtehset it to HIGH
modlesthat's exactly what im doing
modleswhen i set to HIGH, it bombs
pwillardthose are your choices
cehtehwhat bombs?
cehtehwhat exactly happens?
modlesthe micro resets
cehtehso its your code
pwillardYou are fighting with an existing pullup resistor
cehtehthe pullup should be high enouh
cehtehi hope at least
pwillardso use an open collector or drain solution... problem solved
cehtehstill .. when it resets then its likely a error in your code
cehtehuse for(;;); instead a delay
modlesi know why your saying that, because ive helped enough others to debug issues like this, but its not the code
cehtehwell figure out step by step what else
modles2 secs ill put together a MVP codebase
pwillardyeah, something smells fishy
cehtehdoes it reset when you dont connect the pin to the gps?
modlesno, all is ok
cehtehjust think about how you can test
pwillardit SHOULD be enabled if you leave it alone... due to the built in pullup
modlesit is
modlesbut i need to be able to turn it on and off
cehtehand your code run and enables (the disconnected) pin and it does not reset?
modlesonly resets when wire is physcially connected
cehtehdid you connect *all* grounds?
pwillardYou only need to pull the pin to GND
cehtehwhat board are you using anyway?
pwillardand transistor can do that
modlesrocket steam mini ultra
modlesyeah i will try the transister route, it just feels overkill
cehtehis there a blocking cap at vcc? 100nF increase it
cehtehbut still i bet you made an error
cehtehcabeling or software
cehtehthe GPS pin *is* already pulled high, when you set the output high there shoudnt be any change or current flowing
modlesok let me measure the voltage of the floating enable pin
cehtehcoment all code in loop out
cehtehjust debug step by step
modlesill just do this in setup..
modlespinMode(6, OUTPUT);
modles digitalWrite(6, LOW);
modles delay(10000);
modles digitalWrite(6, HIGH);
cehtehwhen does delay overflow btw?
cehtehanyway try that, if that doesnt work comment the set HIGH part out too
cehtehsee if it starts with the gps disabled without the avr resetting
modlesyeah crashes on the enable
modlescomment out the HIGH and all is ok.
modlesif HIGH is commented out, it gets to the 'end'
modlesif HIGH is enabled it never gets to 'enable', resets before it has time to dump the serial
cehtehso what voltage regulator do you have there?
cehtehsome tiny 3v3 on the arduino right?
modlesyeah but as i say if i manually connect the enable pin to the output of the 3v3 regulator, its fine, enables and doesnt crash
cehtehi bet its like i saied earlier that the GPS draws too much power on enabling
cehtehthen check your cabeling again
cehtehor use a transistor like pwillard saied to pull it down
cehtehand then, measure what currents are flowing over the transistor
cehtehmaybe you just read the datasheet of the gps
CygniXwhat is a clear explanation for connecting a capacitor in parallel to the power inputs of a device not getting enough power from an arduino?
modlesdecoupling capacitor
cehtehyou may try that, but just placing more caps isnt always good, the regulator has some limits on the output caps it can handle
CygniXexample case:
modlesah sod it, im just going to set the thing into standby via a PMTK command
cehtehyoiu should rather care about the arduino seeing proper voltage than the servo
cehtehwell he does many things wrong and that question is old
CygniXthis came from here, cehteh,
CygniXlast updated 2015
cehtehusb and arduino on board regulator could only power very small servos if at all
cehtehyou need some better power source, and no cap will improve that significantly, even a small 9gramm servo can draw close to 1A when stalled
CygniXI am employing a similar approach to a project (no servos)
cehtehthen it is not similar
CygniXusing a capacitor solves the problem in my case
cehtehdepends on the load
cehteha cap can only bridge for very very short time, if thats the case, its ok
cehtehdepending on the size of the cap and the current you draw of course
CygniX4.7uf in my case
CygniXbut I think I need to go bigger
cehtehyou cant increase such a cap arbirarly
cehtehit needs to be charged and the regulator in the incoming side needs to handle it
cehtehand you cant draw more power out than you can supply in, caps are no magic power generators
CygniXthe alternative is to use a second power supply
CygniXit could also be a limitation due to using USB as power source
CygniXI going from 4.7 to 6.8, and if at 10, there is still issue, I will find a different solution
cehtehyou may add a small resistor in front few ohms only
CygniXin front where?
cehtehor a full LC filter
badloopso.. i'm pulling gpio0 to ground and resetting this nodemcu i got but it still fails uploading the sketch for some reason. anything i can check to figure out why?
cehtehthe 560Ohms stands for the arduino, the 0.1ohm for the inner resistance of the voltage source
cehtehyou can also reverse some things there to keep the ardino side more stable
cehtehthats actually better
cehtehaccept a small voltage drop on the arduino for a stable voltage
CygniXI was looking into the LC filter, not a bad idea
cehtehbe careful about oscillations and inductive kickback
CygniXmy capacitor collection variety needs major improvement
LikWidChzAnyone here good at coding with u8g2lib? for lcd screens and wut not... I draw a triangle and want to clear it, without clearing the entire screen... is that possible?
cehtehdraw it again in reverse?
zhanxor draw it again in the background color
cehtehthats what i meant with reverse .. depending on your draw mode, i dont know that lib
root-xI have problems connectin from PC<-->Arduino<-->GSM
root-xI used this code
root-xThe problem is: I can send commands to the module but not receive data from... i receive incomprensible caracters.
jrwrtoo fast root-x
jrwrtry 9600 and work up
root-xjrwr i tested with different baud rates 9600 and others
root-xall same
root-xi can send to the module but not receive comprehensible data
root-xi can make a call but can't read sms's
ozzzyhow do you know that the module is getting a good command
root-xThe code not is correct at all? ... i connect via Arduino monitor serial
root-xozzloy i can call to my another phone via monitor serial
root-xall in 115200
LikWidChzcehteh - zhanx --- thank you for the suggustions, I also have tried this and I don't believe the syntax allows me to do just that. It seems like the only options are to clear the entire screen.
root-xmmm im thinking.... the module have auto-baudrate...... when connected with the service provider it modify the baudrate to the max
CygniXcehteh: per our previous discussion on using capacitor to smooth out current delivery, if using say, 10uF/25V capacity, though the device can only handle 5v input, is this a problem?
cehtehyou want to overrate caps yes
cehtehhigher voltage
CygniXbut is that bad for my device
CygniXsorry, it was a question
cehtehcaps fail when they see a voltage higher than their rating, lower is fine
LikWidChzroot-x -- do you have a buspirate? or usb to serial device? try different baud rates as explained above
cehtehand that means worst case voltage which may even seen for a split second
CygniXcehteh: I am asking whether it is bad for the device, that I am using the capacitor to feed power, the device which specifies max 5v input
root-xLikWidChz as say later PC<-->Arduino<-->GSM module
root-xArduino drivers.
cehtehCygniX: you only supply 5V right?
cehtehthen its fine
CygniXmore like 3.5v
cehtehalways pick a cap with a higher voltage rating
cehtehshould be ok too
CygniXOK thanks
cehtehmaybe bit big a smaller one would do as well but thats only the maximum rating for the cap
CygniXI think I will have to move away from this method, perhaps swith to 2560 rather than uno
CygniXI mean mega
LikWidChzwhats wrong with either of those?
CygniXLikWidChz: was that a question for me?
CygniXthere appears to be a current distribution issue, due to sharing, on the uno board
CygniXthe mega (2560) has another dedicated 5v port
LikWidChzrun all the stuff that requires voltage off a seperate source
CygniXthat's another approach
LikWidChzunless its an led or something that doesnt need a bunch of current, dont risk it. Ebay has a lot of cheap options 12v to 5v 3amp regulators..
LikWidChzwhen you need 1, buy 5 and keep the extra for later.
CygniXso if I need 5, buy 25?
LikWidChzwell you know whatever works!
CygniXLikWidChz: What do you think of these:
LikWidChzYeah those would work, you adjust the output voltage with that trim pot?
CygniXthat's what it looks like
LikWidChz same thing, cheaper
CygniXyea, too bad it's ebay
LikWidChzAlso the other option is a LMR3xx something something chip, its a single looking device that looks like a FET. Nothing wrong with ebay, people seem to think ebay and differ. its all the same stuff
LikWidChz This is cheap
HrdwrBoBLikWidChz: well
HrdwrBoBthere's a large crossover
HrdwrBoBbut "
LikWidChzthose linear voltage regulators are pretty nice, if you don't draw a lot of current you dont need a heatsink
HrdwrBoBbbut "too bad it's ebay" - what does that even mean
LikWidChzehh no point in getting into a pissing match about it, who cares :)
CygniXI actually have this:
LikWidChzI mean the guy was asking questions about some hardware for his project, threw him some ideas... ideas are the thing that solve problems :) But everyone has their own opinion about ish..
LikWidChzYeah those will work CygniX -- same thing as what I posted from mouser
CygniXpaid $0.25 for it but it took for eeeeever for it to be delivered
LikWidChzright, thats why you order 40 of them and keep them in a drawer
LikWidChzsee before I said you order 5, now I said 40... you see where this is going I buy too much shit for projects I havent started.
CygniXwell, it was part of a larger order
LikWidChzyeah, just make sure your project doesnt draw a lot of current those things get hot.
CygniXfuturlec is cheap for certain parts but deliever can take months
LikWidChzcough ebay cough, most of the crap I buy from ebay comes form china, most of it takes less than 2 weeks to oregon.
LikWidChzright now im waiting for some thermoucouple modules ... max81655 breakout boards
LikWidChzany day now.........................