Single wire UART and oscillator questions SAML21E

Log in or register to post comments
Go To Last Post
4 posts / 0 new
Author
Message
joggem
joggem's picture
Level: New Member
Joined: Thu. Jul 15, 2021
Posts: 5 View posts
#1
Posted by joggem: Thu. Jul 15, 2021 - 01:49 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

 

Hello Atmel Community,

 

This is my first experience with Microchip studio. I've been starting a project where I need a single wired UART connection. 

The microcontroller I'm using is the SAML21E18B. As found in the datasheet it should be able to use this functionality. 

To start a project in Atmel Studio I'm using Atmel Start. There is no way I can find to use UART in half duplex mode. 

 

Also I'm wondering how to set the clock of the microcontroller to 48MHz. I want to configure the microcontroller such that it uses the 48Mhz clock speed when it needs performance, for the other tasks I'm planning to only use the LP internal oscillator. How to fix the explenation mark for the 48MHz oscillator. Should I add an external oscillator for these frequencies? 

 

 

 

Thank you,

 

Joggem

 

Attachment(s): 

Image icon clock.PNG
Image icon uart.PNG
This topic has a solution.

Tags:

Tools, Atmel Software Framework (ASF) and Atmel Start (ASFv4) (ARM-related), solved
Last Edited: Fri. Jul 16, 2021 - 12:15 PM
Top
joggem
joggem's picture
Level: New Member
Joined: Thu. Jul 15, 2021
Posts: 5 View posts
Posted by joggem: Thu. Jul 15, 2021 - 02:43 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I solved the 48MHz clock frequency problem by using an external 32KHz oscillator!

Now I'm wondering where to assign the XIN32 and XOUT32 in Atmel Start. Since the datasheet of the SAML21 notes that PA00 and PA01 used. 

 

Also, I still cant find the single wired half duplex UART mode...

Attachment(s): 

Image icon clock fixed.PNG
Top
ki0bk
ki0bk's picture
Level: 10k+ Postman
Joined: Mon. Sep 8, 2014
Posts: 10654 View posts
Location: Over the rainbow
This reply has been marked as the solution. 
Posted by ki0bk: Thu. Jul 15, 2021 - 03:55 PM
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I've never used one of these, but found this appnote: https://ww1.microchip.com/downlo...

Chapter 10 has UART mux settings, two talk about half duplex mode

 

Jim

 

 

FF = PI > S.E.T

 

Top
joggem
joggem's picture
Level: New Member
Joined: Thu. Jul 15, 2021
Posts: 5 View posts
Posted by joggem: Fri. Jul 16, 2021 - 12:14 PM (Reply to #3)
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thank you Jim!

 

Reading the document it seems as easy as just connecting the RX and TX to the same pin. For some reason Atmel Start won't allow this feature, so it should be done manually I guess.

 

Jorg

Top