about crtstal oscillator

Log in or register to post comments
Go To Last Post
18 posts / 0 new
Author
Message
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
#1
Posted by balvendra: Tue. Jul 4, 2017 - 06:01 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

what is the maximum frequency crystal oscillator we can connect to ATMEGA 32 mcu.

when i connect 4 Mhz crystal it's working .

when i connect 8  Mhz crystal it's working but not in proper way.

when i connect 16 Mhz crystal it's not working and when i connect it for code transfer it fail so what i do please help me

Tags:

AVR Microcontrollers, megaAVR and tinyAVR
Top
awneil
awneil's picture
Level: 10k+ Postman
Joined: Fri. Jul 1, 2005
Posts: 17589 View posts
Location: Basingstoke, Hampshire, UK
Posted by awneil: Tue. Jul 4, 2017 - 06:17 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

What does the datasheet tell you?

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillator: https://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Top
ka7ehk
ka7ehk's picture
Level: 10k+ Postman
Joined: Fri. Nov 22, 2002
Posts: 20745 View posts
Location: Tangent, OR, USA
Posted by ka7ehk: Tue. Jul 4, 2017 - 06:21 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

What  is the MCU supply voltage (at the MCU's power pins)?

 

Jim

Jim Wagner Oregon Research Electronics, Consulting Div. Tangent, OR, USA http://www.orelectronics.net

Top
Brian Fairchild
Brian Fairchild's picture
Level: Raving Lunatic
Joined: Thu. Oct 18, 2001
Posts: 4391 View posts
Location: Eastern England.
Posted by Brian Fairchild: Tue. Jul 4, 2017 - 06:43 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

balvendra wrote:

what is the maximum frequency crystal oscillator...when i connect 4 Mhz crystal...

 

An oscillator is not a crystal. Which are you using? You need to learn the difference or one day you will set your fuses wrongly.

#1 This forum helps those that help themselves

#2 All grounds are not created equal

#3 How have you proved that your chip is running at xxMHz?

#4 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand." - Heater's ex-boss

Top
awneil
awneil's picture
Level: 10k+ Postman
Joined: Fri. Jul 1, 2005
Posts: 17589 View posts
Location: Basingstoke, Hampshire, UK
Posted by awneil: Tue. Jul 4, 2017 - 06:56 AM (Reply to #4)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 1

Brian Fairchild wrote:
An oscillator is not a crystal ... You need to learn the difference

This may help: https://e2e.ti.com/support/micro...

 

EDIT

 

See also: https://www.avrfreaks.net/forum/e...

 

 

EDIT 2

 

But note that the AVR datasheet terminology is unhelpful: https://www.avrfreaks.net/comment...

 

 

#CrystalVsOscillator

 

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillator: https://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Last Edited: Tue. May 29, 2018 - 02:02 PM
Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Tue. Jul 4, 2017 - 06:59 AM (Reply to #3)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

5 volt

Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Tue. Jul 4, 2017 - 07:02 AM (Reply to #4)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

this was mistook in typing i am using external crystal

Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Tue. Jul 4, 2017 - 07:04 AM (Reply to #2)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

from data sheet i could not get idea about that so i am asking here

Top
Brian Fairchild
Brian Fairchild's picture
Level: Raving Lunatic
Joined: Thu. Oct 18, 2001
Posts: 4391 View posts
Location: Eastern England.
Posted by Brian Fairchild: Tue. Jul 4, 2017 - 07:11 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

At 5V a mega32 should run with a 16MHz crystal.

 

What value capacitors have you connected to the crystal?

 

What are your fuses set to?

#1 This forum helps those that help themselves

#2 All grounds are not created equal

#3 How have you proved that your chip is running at xxMHz?

#4 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand." - Heater's ex-boss

Top
awneil
awneil's picture
Level: 10k+ Postman
Joined: Fri. Jul 1, 2005
Posts: 17589 View posts
Location: Basingstoke, Hampshire, UK
Posted by awneil: Tue. Jul 4, 2017 - 07:15 AM (Reply to #8)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

balvendra wrote:
from data sheet i could not get idea about that

Really??

 

surprise

 

 

EDIT: See also the sections titled, "Clock Sources" (p25) and "Crystal Oscillator" (p26) 

 

Page references to the 2503Q–AVR–02/11 document revision.

Top Tips:

  1. How to properly post source code - see: https://www.avrfreaks.net/comment... - also how to properly include images/pictures
  2. "Garbage" characters on a serial terminal are (almost?) invariably due to wrong baud rate - see: https://learn.sparkfun.com/tutorials/serial-communication
  3. Wrong baud rate is usually due to not running at the speed you thought; check by blinking a LED to see if you get the speed you expected
  4. Difference between a crystal, and a crystal oscillator: https://www.avrfreaks.net/comment...
  5. When your question is resolved, mark the solution: https://www.avrfreaks.net/comment...
  6. Beginner's "Getting Started" tips: https://www.avrfreaks.net/comment...
Last Edited: Tue. Jul 4, 2017 - 07:21 AM
Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Tue. Jul 4, 2017 - 07:32 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Capacitor - 22 pf
Fuse - EE OD

Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Tue. Jul 4, 2017 - 08:15 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I set fuse bit using eclipse like this

Attachment(s): 

Image icon IMG_20170704_134259.jpg
Top
Brian Fairchild
Brian Fairchild's picture
Level: Raving Lunatic
Joined: Thu. Oct 18, 2001
Posts: 4391 View posts
Location: Eastern England.
Posted by Brian Fairchild: Tue. Jul 4, 2017 - 08:41 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

balvendra wrote:
Capacitor - 22 pf Fuse - EE OD

 

 

I'd be tempted to give the crystal a bit longer to start up. Unless I'm in a hurry I always use the slowest settings...

 

 

#1 This forum helps those that help themselves

#2 All grounds are not created equal

#3 How have you proved that your chip is running at xxMHz?

#4 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand." - Heater's ex-boss

Top
clawson
clawson's picture
Level: Moderator
Joined: Mon. Jul 18, 2005
Posts: 98192 View posts
Location: (using avr-gcc in) Finchingfield, Essex, England
Posted by clawson: Tue. Jul 4, 2017 - 08:47 AM (Reply to #12)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Your picture shows CKOPT set to No.
.
It MUST be enabled for crystals of 8MHz and above or the drive is not strong enough for it to resonate.

Top
MicroGyro
MicroGyro's picture
Level: Hangaround
Joined: Tue. Jul 12, 2011
Posts: 361 View posts
Posted by MicroGyro: Tue. Jul 4, 2017 - 09:03 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

clawson wrote:
Your picture shows CKOPT set to No.
.
It MUST be enabled for crystals of 8MHz and above or the drive is not strong enough for it to resonate.

I had never programmed ckopt unless I need to drive other device with the same clock source or noisy environment.
.

I guess the OP is working with UART or time critical.
How can he be sure it's working or working but not in the proper way?

.

MG

I don't know why I'm still doing this hobby

Top
Brian Fairchild
Brian Fairchild's picture
Level: Raving Lunatic
Joined: Thu. Oct 18, 2001
Posts: 4391 View posts
Location: Eastern England.
Posted by Brian Fairchild: Tue. Jul 4, 2017 - 09:09 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

MicroGyro wrote:

How can he be sure it's working or working but not in the proper way?

 

Aha, I wonder if the OP means that his programming fails? In which case, are we looking at an ISP speed issue?

#1 This forum helps those that help themselves

#2 All grounds are not created equal

#3 How have you proved that your chip is running at xxMHz?

#4 "If you think you need floating point to solve the problem then you don't understand the problem. If you really do need floating point then you have a problem you do not understand." - Heater's ex-boss

Top
balvendra
balvendra's picture
Level: New Member
Joined: Sat. Jun 27, 2015
Posts: 9 View posts
Posted by balvendra: Wed. Jul 5, 2017 - 03:46 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

22 pf capacitor is right value???
and i am using usbtiny so can it communicate with mcu at all frequency??

Top
MicroGyro
MicroGyro's picture
Level: Hangaround
Joined: Tue. Jul 12, 2011
Posts: 361 View posts
Posted by MicroGyro: Wed. Jul 5, 2017 - 05:35 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

balvendra wrote:
22 pf capacitor is right value???
and i am using usbtiny so can it communicate with mcu at all frequency??

You mean your usbtiny? Of course you can.
Set your isp clock 1/4 of your mcu clock.
.
Brian Fairchild wrote:
Aha, I wonder if the OP means that his programming fails? In which case, are we looking at an ISP speed issue?

You are right :D
.
MG

I don't know why I'm still doing this hobby

Top