Programmable XBee 900HP S3B - Developer expectations when using the MC9S08QE32??

I have scoured through the S3B Programmable’s datasheet quite a bit (280 pages of it) and feel that it’s pretty straight forward, but one thing I can’t quite wrap my head around just yet is how the device is configured when considering the GPIO lines run “in parallel” with the stock processor on the radio.

The manual says the UART on the stock processor is intercepted by the Freescale, and that the Freescale provides a separate UART to the one exposed to the user on the chip (pins 2 and 3) to channel communication through itself instead. Got it.

How do we handle other GPIO since it is “in parallel?” Specifically:

1.) How does configuring the DIO with pull-ups and pull-downs come into play now when using XCTU? Do I “disable” them and assign the 40k pull-up like the manual advises? Do I need to do anything on the Freescale side to ensure the Freescale board disables/pinups these GPIO pins as well, or does doing it through XCTU ensure it is accounted for on the Freescale?

2.) Do we basically need to become familiar with the MC9S08QE32 datasheet in its entirety, or is the point of the SDK to completely abstract that aspect away from the developer?

3.) Are there any examples projects outside the SDK (or maybe one that I missed within the SDK) that show us how to sample IO, send it out, but also control outputs to devices based on sensor inputs and utilize the Freescale as a small controller? Presumably that’s part of the added value here since the regular units can use IC and IR already to send in their DIO changes.

Thanks everyone.


Depending on which processor is using the ADC/DIO functions depends on if it needs to be enabled or disabled on the other processor.

No, it is a good idea to get somewhat familiar with the MCQ9S processor as you go through the examples so you have a better idea of how it works.

There is an example in the SDK that should give you want you are looking for on the DIO line control. I believe it is called Knight Rider.

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Ok, lets say I configure all of my inputs in XCTU, both analog and digital. I also set Vref to 2.5V in XCTU, since it doesn’t let me set it to 3.3V. I also plan on setting Vref to 3.3V physically by jumpering to Vcc.

Then lets say I want to control the function of an output except I want to do it from the Freescale. Do I disable the output pin in XCTU, or leave it as an output?

What would I do in Freescale for the inputs?

I’ll check out the Knight Rider example. Thanks.

You would need to disable the pin on the RF processor and then set it to the desired value on the FreeScale processor.