ENC28J60 driver and lwIP port

This repository contains a generic ENC28J60 driver with hardware abstraction and an lwIP network interface port. An example implementation for the hardware abstraction is provided for the EnergyMicro Gecko microcontroller, on which the example of an lwIP project using the driver can be run.

It provides all the functionality required for stable send/receive operation (was tested against concurrent flood pings and TCP requests), but has room for extension, especially with respect to error reporting and optimization. (Current code relies on polling only, and utilizes neither DMA nor interrupts.)

The official website of this repository is at GitLab; please report issues or send pull requests there. The project's documentation can be built with Doxygen

Quick start

• Get a ENC28J60 chip with UEXT connector (MOD-ENC28J60 from Olimex)

• Get a Gecko chip with UEXT connector (EM-32G880F128-H from Olimex) with a power supply (the programmer only measures and does not power)

• Get an SWD programmer (ST-Link/V2)

• Wire everything up the only way the connectors fit

• Get openocd (eg. from Debian, tested with version 0.9.0)

• Get an arm-none-eabi-gcc and -gdb (eg. from the Debian package gcc-arm-none-eabi and gdb-arm-none-eabi)

• Get the EFM32 emlib and CMSIS sources. Not everything contained in there is free software, but the parts used in the netblink example are:

    cd examples/netblink
    wget http://www.silabs.com/Support%20Documents/Software/Gecko_SDK.zip
    unzip Gecko_SDK.zip -d Gecko_SDK Device/\*.\[hc\] Device/\*/GCC/\* emlib/\*.\[hc\] CMSIS/\*.h
  

• In the same directory, fetch the lwIP library ...

    git clone git://git.savannah.nongnu.org/lwip.git -b DEVEL-1_4_1
  

• ... and build the example code:

    make
  

• Start openocd:

    openocd -f openocd.cfg
  

  Leave this running and continue in another terminal.

• Upload the program and let it run independt of the debugger:

    make upload reset
  

• Configure your Ethernet interface as 192.168.0.1/24

• Test everything:

    socat udp:192.168.0.2:1234  -
  

• Enjoy that the LED blinks every time you send a line.

Debugging

• You can easily start a debuggin session with make gdb. The program can be flashed from inside gdb as using the load command, a reset using run.

ENC28J60 driver

The driver itself resides in ./enc28j60driver/. It is basically stack agnostic, ie. it just implements typical operations conducted with the ENC28J60 (eg. setup, doing a self test, reading a received frame into pre-allocated memory).

If compiled with -DENC28J60_USE_PBUF, two small additional functions, @ref enc_read_received_pbuf and @ref enc_transmit_pbuf, are added, which are designed to use the lwIP pbuf memory management system. This is to keep the interfaces simple.

lwIP port

The lwIP netif implementation for the driver resides in lwip/netif, following the naming structure of the lwIP project (at least I hope so).

It is suitable for lwIP version 1.4.1 and the current (as of 2013-01-22) 1.5 development version.

Due to the interfaces provided by the driver itself, it is rather minimal, and only consists of a init and a polling routine (which, as the name implies, is to be called as often as possible).

EFM32 backend

An implementation of the hardware backend for the EFM32 Gecko platform can be found in efm32/enchw. It utilizes the free (zlib-style licensed) emlib library provided by EnergyMicro, and manages transmission of bytes over the chips' SPI peripherials. The very pinouts are defined in the enchw-config.h files, which are provided for particular development boards in efm32/boards/, along with very simple board drivers that are used in the examples.

ASF backend

An implementation of the hardware backend for Atmel SAM devices can be found in asf/enchw. It utilized Atmel Software Framework (ASF) http://www.atmel.com/tools/avrsoftwareframework.aspx which is available under modified 4-clause BSD license. Multiple devices are supported. As soon as SPI may be shared between ENC28J60 and other slaves, it is for user to allocate and provide pointer to properly initialized struct spi_module as well as to initialize struct spi_slave_inst.