Single wire UART and oscillator questions SAML21E

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joggem
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Posted by joggem: Thu. Jul 15, 2021 - 01:49 PM
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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

 

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Tools, Atmel Software Framework (ASF) and Atmel Start (ASFv4) (ARM-related), solved
Last Edited: Fri. Jul 16, 2021 - 12:15 PM
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joggem
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Posted by joggem: Thu. Jul 15, 2021 - 02:43 PM
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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...

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ki0bk
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Posted by ki0bk: Thu. Jul 15, 2021 - 03:55 PM
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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

 

 

Keys to wealth:

Invest for cash flow, not capital gains!

Wealth is attracted, not chased! 

Income is proportional to how many you serve!

 

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joggem
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Posted by joggem: Fri. Jul 16, 2021 - 12:14 PM (Reply to #3)
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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

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