topic Re: 1Wire UART circuit in Kinetis Microcontrollers

1Wire UART circuit

jhd — Tue, 02 Jul 2019 22:13:04 GMT

Hello,

There is some AN or example aobut 1Wire UART circuit for Kinetis?

Best regards

Re: 1Wire UART circuit

kerryzhou — Wed, 03 Jul 2019 02:25:50 GMT

Please tell me which kinetis chip you are using? Tell me the chip part number, I will help you to check whether that chip can support the single wire UART or not.

Some kinetis chips UART module can support the single-wire operation, about the document, you can refer to the chip reference manual directly.

Take K22 chip as ane example:

You also can check your kinetis chip reference manual by yourself.

Wish it helps you!
Have a great day,
Kerry

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Re: 1Wire UART circuit

jhd — Wed, 03 Jul 2019 06:30:36 GMT

Thank you,

I'm using de KL03 32kb but has not DMA, so I'm going to use KL05. MKL05Z32VFM4 or MKL05Z32VFK4

Best regards

Re: 1Wire UART circuit

kerryzhou — Wed, 03 Jul 2019 06:49:15 GMT

Hi Javier Hernandez,

Thank you for your updated information.

So, please refer to the KL05 reference manual, chapter:

37.3.4.3 Single-wire operation

This chip UART0 also support the single-wire operation.

Wish it helps you!
Have a great day,
Kerry

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Re: 1Wire UART circuit

jhd — Wed, 03 Jul 2019 07:25:18 GMT

Perfect!

Re: 1Wire UART circuit

jhd — Wed, 03 Jul 2019 07:44:26 GMT

Sorry Kerry,

In KL03 Reference Manual say that KL03 has open-drain in uart so is possible to 1-wire, but KL03 has not DMA module, I think.

ISO7816 protocol is intended to be handled in software for this product. To support smart card reading, TxD pin can be configured as pseudo open drain for 1-wire half-duplex like ISO7816 communication via SIM_SOPT5[LPUART0ODE].

This circuits should be works: