Forum - MCS Electronics

 

FAQFAQ SearchSearch RegisterRegister Log inLog in

Atmega328pb - cannot get any LED's to turn on!?
Goto page Previous  1, 2
 
Post new topic   Reply to topic    www.mcselec.com Forum Index -> BASCOM-AVR
View previous topic :: View next topic  
Author Message
albertsm

Administrator



Joined: 09 Apr 2004
Posts: 5199
Location: Holland

blank.gif
PostPosted: Fri Jan 08, 2021 10:26 pm    Post subject: Reply with quote

with an ohm meter measure all GND and VCC/AVCC pins (with power off) and see if they are all actually connected !
this means : are all GND pins actually connected to ground.
are all vcc and avcc pins connected to your vcc power?

then check in volt mode again with power applied and see if the levels are ok.

also : which casing are you using? Does it match the datasheet/cad circuit?
some casing have different pinning.

_________________
Mark
Back to top
View user's profile Visit poster's website
Printpix52

Bascom Member



Joined: 18 Jun 2014
Posts: 245
Location: D.F.

mexico.gif
PostPosted: Sat Jan 09, 2021 12:20 am    Post subject: Reply with quote

I think the problem is the LED resistor replaced by 82 ohms. Very Happy
Back to top
View user's profile
Printpix52

Bascom Member



Joined: 18 Jun 2014
Posts: 245
Location: D.F.

mexico.gif
PostPosted: Sat Jan 09, 2021 12:25 am    Post subject: Reply with quote

To calculate resistances......

https://www.inventable.eu/paginas/LedResCalculatorSp/LedResCalculatorSp.html
Back to top
View user's profile
SZTRAD

Bascom Member



Joined: 30 Dec 2019
Posts: 104

blank.gif
PostPosted: Sat Jan 09, 2021 9:51 am    Post subject: Reply with quote

I would be very careful with that.
I recommend reading the electrical characteristics in the data sheet.
Back to top
View user's profile
hgrueneis

Bascom Member



Joined: 04 Apr 2009
Posts: 884
Location: A-4786 Brunnenthal

austria.gif
PostPosted: Sat Jan 09, 2021 3:30 pm    Post subject: Reply with quote

You loaded the chip with the leds without connecting all power pins.
I suspect that one or more internal power lines are blown, maybe also the output buffers.
I would try an other chip.

Regards
Hubert
Back to top
View user's profile
hgrueneis

Bascom Member



Joined: 04 Apr 2009
Posts: 884
Location: A-4786 Brunnenthal

austria.gif
PostPosted: Sat Jan 09, 2021 3:36 pm    Post subject: Reply with quote

I do not think that an 82 ohm resistor would be the problem, since most leds require 1.5 to 3 volts to light up.

Regards
Hubert
Back to top
View user's profile
SZTRAD

Bascom Member



Joined: 30 Dec 2019
Posts: 104

blank.gif
PostPosted: Sat Jan 09, 2021 3:49 pm    Post subject: Reply with quote

This is the standard approach of the programmer and not the person who does the HW.
I did not draw attention to the voltage but to the current. These 4 LEDs almost reach the limit of the chip used.
The disappointment is then terribly great when the chip is smoked. Forget the many connections with arduino and read the data sheets. If nothing else, at least the supply voltage and maximum current. Sometimes try to measure the short circuit current of the port and you will understand.
Back to top
View user's profile
enniom

Bascom Member



Joined: 20 Oct 2009
Posts: 486

PostPosted: Sat Jan 09, 2021 6:01 pm    Post subject: Reply with quote

Tim,

One last guess ...

From the symptoms you describe, it may be possible that the PUD is set.

From the datasheet:



PRINT out the value of MCUCR.PUD to see if it equals 0.

Also note that unlike the Mega328P, the Mega328PB has a JTAG interface with a corresponding fuse bit. Make sure that it is disabled. It is not clear from the datasheet which pins are affected, but its possible that the JTAG overlays on the SPI pins.

If the JTAG is set, bit 7 of the MCUCR register should be 1.

E
Back to top
View user's profile
TSEYFARTH

Bascom Member



Joined: 01 Jul 2006
Posts: 1054

usa.gif
PostPosted: Tue Jan 26, 2021 10:15 pm    Post subject: Reply with quote

Found the problem!

It was running too fast - 16MHz. The max on 3.3v is 10MHz. Using divide by 8 fuse and quick change to the code corrected the problem.

Thought I'd let everyone know...

Thank you for all of the suggestions and help!
Tim
Back to top
View user's profile
Display posts from previous:   
Post new topic   Reply to topic    www.mcselec.com Forum Index -> BASCOM-AVR All times are GMT + 1 Hour
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum