AT91SAM9X TWI Problem

Discussion around AT91RM9200 and SAM9 Series Products.

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RighardtGuse
Posts: 6
Joined: Fri Oct 01, 2010 11:38 am

AT91SAM9X TWI Problem

Mon Oct 11, 2010 4:20 pm

Hi,

Hope everyone's doing well....?

Please be so kind to assist with the following problem....

I'm using the at91sam9xe-ek (evaluation kit) and I'm stugling to get the TWI working. I'm using the basic-twi-eeprom example from the Softpack 1.5 provided on Atmel website.

I replaced the at24c512 EEPROM with at24c1024 as the driver is written specifically for that.

I get the following errors when trying to write/read from the device:

"TWID Timeout BS"
"TWID Timeout BR"

I did not change anything in the softpack example... compiled it and run it on the board - doesn't work!


Please help,
Thank you,
Righardt
jepa
Posts: 2
Joined: Fri Feb 10, 2012 7:19 pm

Re: AT91SAM9X TWI Problem

Tue Mar 06, 2012 10:11 pm

Did you find the solution of the problem? I have the same situation and maybe you can help me.
Thanks
sztechnovo
Posts: 5
Joined: Wed Mar 21, 2012 11:10 am

Re: AT91SAM9X TWI Problem

Wed Mar 21, 2012 3:11 pm

hi, not sure if you have the problem solved. if not, it could be that the addressing of the two eeprom is different. 24c512 has a 16bit address, yet 1024 has 17. so for twi, the first byte to transfer on the wire has different meanings. for 512, it's 1010[phy_address][r/w], where phy_address is a 3bit address refering up to 8 different chips; for 1024, it's 10100[phy_address][msb_of_address][r/w], where phy_address is a one bit address refering up to 2 different chips, and msb_of_address refers to the most significent bit of the 17bit address space. so the driver should be different, and you may have to reconfigure your system to make it work. hope it helps
jchan12345@yahoo.com
Posts: 1
Joined: Fri Mar 11, 2016 11:26 am

Re: AT91SAM9X TWI Problem

Fri Mar 11, 2016 12:07 pm

I get the following errors when trying to write/read from the device:

"TWID Timeout BS"
"TWID Timeout BR"

Do you know how to solve this problem ?
erickrieg
Posts: 2
Joined: Tue Aug 04, 2015 10:06 pm

Re: AT91SAM9X TWI Problem

Fri Apr 08, 2016 4:31 pm

I have a TWI problem with the V71, It may use the same internal TWI engine as your processor. My eval board usually can communicate fine with I2C to an external IMU circuit I wired in. But on one of our own made boards, I had a tough problem for a number of days where I could reconfigure the data and clock wire to be direct controlled and move them ok - but I had trouble when configuring for TWI to get the lines to move on a scope. It was almost as if perhaps the system clock wasn't making it to the TWI engine - the problem seemed to just vanish from making subtle timing changes that should have had no affect on things. Right now the eval board properly communicates with a wired IMU via I2C, but the very latest of our own board with pretty much the same code does not. I believe my problem with a IMU would likely be the same as if I tried to get it to talk to a specific I2C eeprom -I get time outs on getting anything back, but before that happens, the I2C engine just isn't even moving the lines

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