Project

General

Profile

mcu sharing pins for spi with rfm69 and an i2c device

Added by manu-fwi almost 5 years ago

Hi all,
I would like to connect an rfm69 to a small attiny (not a lot of available pins) and at least one or perhaps several i2c devices. I want to use the usart of the attiny whice means that all devices would share the same pins. Question is: does the rfm69 tri-state its spi ports when unselected?
I’ve read also about the interrupt causing rfm69 to grab the spi port but there won’t be a lot of traffic with all the devices, so I can probably work around that; moreover the rfm69 as a big enough fifo to be able to wait that the i2c transaction is done, right?
TIA,
Manu


Replies (4)

RE: mcu sharing pins for spi with rfm69 and an i2c device - Added by JohnO almost 5 years ago

I’m unable to answer your question unfortunately but you have set me wondering what your drivers are to use an ATTiny for this job.

RE: mcu sharing pins for spi with rfm69 and an i2c device - Added by manu-fwi almost 5 years ago

For now I plan to do a very crude driver as the attiny is memory constrained, but for now I have nothing concrete…

RE: mcu sharing pins for spi with rfm69 and an i2c device - Added by JohnO almost 5 years ago

I am looking for your motivation in choosing to use the ATTiny processor rather than a device with more I/O pins.

RE: mcu sharing pins for spi with rfm69 and an i2c device - Added by manu-fwi almost 5 years ago

It’s cheap and I want to make very small remote sensors, so normally the code should fit and I dont need alot of I/O. Moreover I have seen an attiny with power boost included which means very small parts count. But I did not start the project yet, that might be too tight…

    (1-4/4)