Go Down

Topic: Setting up the second SPI port on the Arduino Uno (Read 2 times) previous topic - next topic

diesel

Nick,

I was messing around with code trying to get it to work, that is why they were different.

I modified as you suggested, but same output......,......,. I did switch back to my first listed code and noticed for a short period of time it would output ......., .......,  then it went back to hello there. Maybe it is a timing thing? I saw something in the datasheet that it talks about setting up interrupts, are those necessary?

Thanks,

-diesel

Nick Gammon

Quote
I am using FTDI breakout from Sparkfun to read.


Read what? The software serial output?

Software serial turns interrupts off for a while. Try using a faster debugging baud rate.

Also it isn't clear what is being echoed from where.

diesel

Nick,

The plan is to use the secondary spi port to use with SPI ram. First, I want to make sure it is working, so now I am just reading and writting from SoftwareSerial. I am attempting to write and read into the SPI port, which works using the hardware spi.

Thanks, I will give the higher baud rate a try.

-diesel


Nick Gammon

It certainly should work, unfortunately sometimes debugging itself obscures what is happening.

diesel

#9
Feb 07, 2013, 06:50 am Last Edit: Feb 07, 2013, 06:52 am by diesel Reason: 1
Nick,

I put a logic analyzer on both so that you could see. I attached two images, 1st with Uart SPI and 2nd with Arduino std SPI. On the Uart SPI I get 255...255,\r,\n from serial. Nothing but 255 for the array of characters. On the Arduino std SPI I get ->hello there \r\n(although not perfect). The best software serial baud seemed to be 38400, I ranged from 9600-115200( best defined by what I received from Arduino SPI) . I also tried connecting the Arduino up with only 9v power supply, disconnecting usb, I thought that might be giving me interference, no change in output, still 255 from Uart SPI. Any other suggestions? I have a arduino mega 1280, perhaps I could give that a try w/the 2nd hardware serial port. Would I have to change the registers?

Thanks,

-diesel

Go Up