Using SPi Master (EB013) and TCP/IP (Wiz810MJ) Components

[leoo]

Hi,

I am using the SPI Master (EB013) and the TCP/IP (Wiz810MJ) components to communicate with different SPI devices on a PCB. Could this potentially cause some communication problems?

I ask because I am experiencing some issues that I can't explain.

Regards.
Leo

[LeighM]

Hi,
What processor are your using? Could you post your project file?
If your target processor only has one hardware SPI, you will need to use software channel for one of the interfaces (e.g. EB013)

Sorry, I was assuming you were using e-blocks on separate ports, but I now see the word pcb
There will likely be issues if you are using common signal lines for both.

[leoo]

Hi Leigh,

Thanks for the reply.

I'm using a PIC24FJ128202, but my design uses one SPI buss to communicate with both a Wiz810MJ and an EEPROM, with each having their own (different) chip select lines. There are no pins available to run separate SPIs.

I was hoping to be able to initialise the EEPROM (SPI_Master_EB013), read the data, uninitialise and then initialise the Wiznet module (TCP_IP_EB023_00_2), but both Components have to be initialised to be able to communicate with either of them, i.e if the TCP_IP_EB023_00_2 is not initialised then you can't comm with the EEPROM and vice versa. I've tried initialising first one then the other, but the order in which they initialise does not seem to make a difference.

Is there a way to initialise/set these devices up without the one interfering with the other? Asked another way; Is there a way to communicate with a Wiz810MJ and a serial EEPROM, both on the same SPI buss, using FC7 currently?

Regards.
Leo

[LeighM]

At a quick look I don't see why initializing and uninitializing should not work, but we will need to look into this issue carefully.
In the meantime, could you try using Software SPI for one, or both, if not already, and see if that works?

[leoo]

Hi,

Some feedback on this issue.

The problems experienced were caused by the buss select chip U3, a SN74CB3Q3257, on the WIZ810MJ module. With this IC removed and the SPI lines connected through, Flowcode has no difficulty, whatsoever, in reading reliably from both Eeprom and WIZ810MJ SPI devices on the same buss.

Another thing to watch for is that some (newer?) versions of the WIZ810MJ module have a 4k7 pull down resistor, R10, on the SPI_EN line. This line needs to be pulled high to enable SPI comms and if you use a pull-up resistor that has the same value, or greater, than R10, then the voltage applied to the W5100's SPI_En input pin may be too low to reliably enable SPI comms. The result is that the Ethernet data (TelNet port) is scrambled similar to, but worse than, an incorrect baud rate on RS232. We have two versions of the WIZ810MJ module in the field, one with the pull-down resistor and one without. To keep our hardware standard ,we remove R10 from the Wiznet module and the problem is solved.

I hope this information is of assistance.

Kind regards.
Leo