Alfat f40 with atmega644p

i want to interface atmega644p with alfat f40 usb v1.4 via SPI
what are the necessary hardware and software requirements?

Not recommended for new designs. All docs can be found here

can i have the datasheet of alfat usb v1.4?
i mean pin layout (1-18)?


it’s in the user manual. In the link Gus provided.

Do you recommend an alternative product for new designs? I have an F40 ALFAT-based project in my queue that I assumed was still going to be good to go, since Mouser still sells the modules. I had purchased the eval kit for use in development. But if you don’t recommend this for new designs, I’d like to go with something that is recommended for new designs. Thanks.

that user manual is of uALFAT which is different from alfat f40 usb v1.4. Secondly, the user manual of uALFAT shows a pin configuration of 46 pins whereas i only got 20 pins on my usb board

ok, a minute on Bing and here’s the schematic for you

The alternative is a custom solution. Please contact us directly to learn about your need.

i am trying to configure atmega644 with alfat SDR v1.2
i have posted my code here. Everything seems fine but somehow the code is not working.
Any kind of help would be appreciated


what part doesn’t work? What troubleshooting have you done? Where’s your wiring diagram/picture?

i am using a max515 ic with my atmega alongwith an spi debugger in proteus

i simulated the file to see if the spi has been initialized. But it has not initialized
Moreover, i tested the code on the actual hardware but no use.

That means you need Arduino help not ALFAT help, doesn’t it?
This is not the primary product set in use at this forum, you may be better off seeking that help elsewhere if time to help is important.

I’m assuming your schematic block up the top with the big blue “SPI” is meant to be the ALFAT?

You do also know that you have to have different CS pins used for multiple SPI devices? You currently only have one shown - that’s just not going to work, you have to have them connected to different pins. Rip the MAX chip out of the circuit and your code and try again.

Edit: plus, how are you controlling the boot state, to get ALFAT into SPI mode?

i didnt know about this boot state. what’s this?

Did you read the manual? There’s a WHOLE section on it… Section 4. The original link Gus sent you had the User Manual linked…

what does this mean?
" The GHI Bootloader always uses the UART interface."

Does this mean that i would have to read the banner via uart interface?

ONLY if you are uploading the firmware via your app (which isn’t a good idea). Going into the bootloader is typically something you would do ONCE, and you’d do that with a serial to USB TTL UART device connected to the ALFAT device.

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i am facing some problems regarding spi initialization. I think i am following some wrong schematic diagram because in software, things are working as they should be.
I am using the following schematic

whereas the alfat board i am using is

I am saying this because schematic gives me pin out naming JP1 whereas on my board i have JP2 instead of JP1. Maybe because of wrong connections i am not getting desired results

that is NOT the Alfat USB that you said you were using (in post #1).

Have you looked on the bottom of the module?

Could u provide me with the schematic diagram of the alfat product i am using?
it is alfat sdr 1.2

really? Are you kidding? Isn’t that what I linked in my post ABOVE your request??