Interfacing ENC28J60 with nRF52833

[choehyunho]

Hi teams,

I am trying to interface ENC28J60 ethernet controller on nRF52833 based board.

The purpose is sending/receiving simple data gathered from BLE mesh network.

I found some examples about SPI communication, and will try to follow them to physically interface the chip, but have some more question to go further.

1. Because I will use DHCP & TCP socket, etc, need simple TCP/IP stack. What is your recommendation?

    I found lwip in SDK/external folder. Is it possible to use on my purpose?

2. To handling incoming/outgoing packets via ethernet, I expect quite complex interrupt/event handling required.

   But, in examples that I reviewed, there is no task/thread handling like RTOS does.

   Where can I find similar example source code which I can refer to?

[Kenneth]

Hi,

You are free to use these as you best see fit. I do believe that the IoT SDK are using some of these modules, so you can use these as guidance:
https://infocenter.nordicsemi.com/topic/struct_sdk/struct/sdk_iot_latest.html

Though moving forward I think maybe using the nRF Connect SDK (NCS) is the way to go. It looks like it is supported:
https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/reference/kconfig/CONFIG_ETH_ENC28J60.html

For more information about NCS check out:
https://www.nordicsemi.com/Software-and-tools/Software/nRF-Connect-SDK/
http://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/index.html
https://devzone.nordicsemi.com/nordic/cellular-iot-guides/b/getting-started-cellular/posts/nrf-connect-sdk-tutorial

Best regards,
Kenneth

[choehyunho]

Thanks for your support.

Since I am using nRF52833 now, I will check about IoT SDK further. NCS is not my scope yet.

I have found some article about GPIOTE handling for external interrupt handling, and about Sheduler Library for avoiding time-consuming works in interrupt context.

Is there any other helpful documents for my situation?

[Kenneth]

choehyunho said:

Is there any other helpful documents for my situation?

Not that I aware of no. I do believe you can find some BLE peripheral examples that are using the scheduler already, so that may help yes.

[choehyunho]

I managed to finsh ENC28J60 to work on nRF52833.

For people who has interest, I leave some comments.

1. I chose uIP stack, not lwIP which is included in nRF SDK.

   It is because lwIP requires memory manager (malloc/free), but causes frequent problem in Mesh SDK.

   I suspect the reason as Mesh SDK uses relatively more memory than normal SDK.

   Anyway, though uIP is lack of some features, and slower than lwIP, but smaller and never uses malloc/free, and fit for my use.

2. To handle RX interrupt correctly, Scheduler Library is useful. It is quite simple and compact to use.

3. nRF SPI library is a little bit weird for me, comparing to other chipsets.

    SPI write/read transfer always returns dummy bytes for the write cycles.

    I should remove them from RX buffer myself.

    And also, because there is no TX and TX transfer in single transfer call, I should manually control SS pin myself.

4. For the helpful resources about porting, I searched lots of web resources, and the following link is fairly useful.

https://github.com/Plytirex/FreeRTOS-TCP-enc28j60