[General] enc28J60 ethernet simplest example

[K33rg4t3]

Hey
I want to create a hello-world application on stand-alone enc28J60 chip (dip package) on breadboard.
Can anyone suggest me which MCU is the best and most document for this purpose? I am looking for some kind of tutorial or example, but most of the examples are using ready boards with this chip while I need to do everything from scratch...

 

[D.A.(Tony)Stewart]

like this?
https://www.sparkfun.com/products/765

 

[K33rg4t3]

No sir, you didn't understand my post completly.

I have a ENC28J60 chip in DIP package and I want to create myself entire project setup on breadboard and later create my own PCB.
The thing you are showing is a ready-to-use PCB when I want to create one myself.

Should I choose a 3.3V MCU for this ENC28J60 or can I stick to 5V ones and ignore signal translation like in some arduino tutorials?

 

[KlausST]

Hi,

Divide your problem in sections.
1) enc hardwrae
2) microcontroller hardware
3) software

In my eyes the given link is a good source on how to do then ENC hardware.

The microcontroller selection. There are many devices, each hast it's benefits and its disadvantage. Cost, processing power, power consumption, periferals, features, RAM, ROM, EEPROM size.. What is important for you and what is the best choice for your application.. It only can be your decision.

A "Hello world" software for the ENC .. I' m sure you find in the internet.

Klaus

 

[K33rg4t3]

1) enc hardware
do I really need the 25 MHz crystal? I don't have this part around...

 

[Aussie Susan]

I strongly suggest that you look at the Microchip MCUs if only because there is a Microchip Library for Applications provided (free) by Microchip for the PIC18, PIC24/dsPIC33 and PIC32 families that contains a library for the TCP/IP stack.
The documentation for the ENC28J60 can be a bit confusing as to how to use the registers to drive the chip, but this is made simpler by the MLA IP stack functions that hide a lot of this complexity from you. You still get the sources for the functions but it can take a while to understand how the drive the chip.
From there you can take it where you need to but at least you will have got something working to move on from.
Also, be careful with breadboards for this type of prototyping. There can be significant capacitance between the lines that can affect the operation of the chips, especially when you need the 25MHz crystal for the ENC28J60.
Susan

 

[KlausST]

Hi,

1) enc hardware
do I really need the 25 MHz crystal? I don't have this part around...

Reading datasheets is essential.

[Table 16-2: Oscillator Timing Characteristics] gives the min and max input oscillator frequency.
--> it leaves not much choice.

Klaus

 

[K33rg4t3]

[Table 16-2: Oscillator Timing Characteristics] gives the min and max input oscillator frequency.
--> it leaves not much choice.

min and max is 25MHz, so I have to... but hey, can't I use the external clock?

2.0 EXTERNAL CONNECTIONS

...

The ENC28J60 may also be driven by an external clock
source connected to the OSC1 pin as shown in

but can I generate this clock signal with PIC MCU with 20MHz Crystal??

 

[Aussie Susan]

Second paragraph of Section 2.1 of the data sheet, and also Figure 2-2.
As Klaus has indicated, you MUST read the data sheet. While I do accept that it can take a bit of practice to understand some Microchip data sheets, this sort of basic information is almost always there.
As for generating the signal from the MCU, yes you can as long as the generated signal is within the parameter specified in Table 16-2. However it also depends on the MCU that you are using - if you are using a 20MHz crystal then it really must have a PLL to increase the internal clock frequency to something much higher. If the MCU has a REFO pin and you can generate the 25MHz through the PLL configuration, then you might be able to use that. You might be able to use the Output Compare module in PWM mode to generate the 50% duty cycle 25MHz purely in hardware from the MCU but we really need to know which MCU we are dealing with to help you better.
But really, for the cost of a 25MHz crystal - typically a dollar or two - and a couple of capacitors, is all this worth it?
Susan