SPI_IRQ PIN -> "Force 1" ?

Hi Mike,

We will check this with our hardware experts and get back to you.

Thanks & Regards,
Raghavendra

Hi Mike,

Take a look at the wlan_start(...) method in wlan.c - it will anser your question. Basically after you set the WLAN_ENABLE pin to high, you should wait for the interrupt pin to go high and then go low.

There is no need for any external pull-up resistors. You are not directly connecting 5 Volts to the CC3000, are you?

Mike Thornhill said:

All,

1.) I am examing the SPI_IRQ pin that is coming out of the CC3000.

From the datasheet:

The pin is an output and at reset the line is Hi-Z. After reset this is "Force 1".

2.) What does "Force 1" mean? Does this mean the line is taken high to VIO_HOST (3.3V) when an interrupt is not being generated? Then taken low (ground) when there is an interrupt?

3.) Is there any need to add an external pullup resistor to this pin? ( I am interfacing a +5V based microcontroller with the +3.3V based CC3000.)

Thanks.

-Mike

To my knowledge: Force 1 means it is set high (~3.3 V)  (no pull resistors). The CC3000 will set this line low as you predicted when there is an interrupt.

I have a direct connection between IRQ and my micro. Are you planning on directly interfacing the IRQ line to a 5 V platform? I presume you have checked to see if your platform will be capable of detecting a transition of 3V OK?

I am powering the CC3000 with 3.3V.

And yes I am interfacing with a 5V platform.

The reason I am asking is that for the ported driver for the ATMEGA 2560 I have found the following note from the author:

"For WLAN_IRQ use a pullup resistor of 10K to 100K Ohm -- one leg to the Arduino input pin + CC3000 SPI_IRQ pin, the other leg to +3.3V."

https://github.com/cmagagna/ArduinoCC3000

The voltage high input minimum is 2.31V so I should be good to go.

-Mike