atsha204a newbie struggle

Log in or register to post comments
Go To Last Post
3 posts / 0 new
Author
Message
Nickelgrass
Nickelgrass's picture
Level: Rookie
Joined: Sat. Aug 3, 2013
Posts: 23 View posts
#1
Posted by Nickelgrass: Mon. Aug 19, 2019 - 06:45 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hello,

I am completely new to the atsha204. I am having difficulty understanding several things.

 

At first I am using a ATmega328PB to interface the two wire I2C bus. At first I want to use the atsha204 only to get random numbers and store values in EEPROM. So I do the wakup sequence (200µS SDA low and then wait 7ms, times are longer just to make sure). Then I scan the bus on all 128 addresses. But I do not get any ACK on any address. What am I missing?

 

Is there a library specific for the AVR in C thats easy to use? I find it hard to understand how this device is interfaced.

 

Glad for any help

 

Thnks

 

Kind regards

Tags:

Security, General Security Discussions
Top
PhillyNJ
PhillyNJ's picture
Level: Resident
Joined: Sat. Oct 11, 2014
Posts: 731 View posts
Posted by PhillyNJ: Mon. Aug 19, 2019 - 10:33 AM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Nickelgrass wrote:

Is there a library specific for the AVR in C thats easy to use? I find it hard to understand how this device is interfaced.

 

 

Microchip has a very good library called CryptoAuthLib (requires login). Packed full of examples. The library supports a HAL interface for connecting with i2c or SWI with any device that support those protocols. There are a few examples on how to implement your own and an Application Note here. I am currently working on added a SWI interface for the ATMEGA328. 

"When all else fails, read the directions"

Top
Nickelgrass
Nickelgrass's picture
Level: Rookie
Joined: Sat. Aug 3, 2013
Posts: 23 View posts
Posted by Nickelgrass: Wed. Aug 21, 2019 - 08:10 AM (Reply to #2)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thanks for the links! Exactly what I was looking for. 

 

Also, I saw one of my pullups on the I2C was not soldered correctly and thus the reason the bus did not work angry Always a bummer looking for a hardware fault in the code. 

Top