RFE power specs

[korda]

In the SNAP hardware tech manual, page 5, power specs reported as:
voltage 2.7 - 3.4V
TX current - 40 mA
RX current - 50 mA
Is this correct that TX module current is less then RX?

To monitor RFE external battery level, is this ok to wire battery + to ADC0 pin 20? What if battery voltage is higher then ADC reference?
The battery is 2 AA pack.

And what is Ch8 low voltage reference and Ch9 high voltage reference?
How the one or another can be used? Is there software switch?

[kbanks]

In the SNAP hardware tech manual, page 5, power specs reported as:
voltage 2.7 - 3.4V
TX current - 40 mA
RX current - 50 mA
Is this correct that TX module current is less then RX?

Yes, per the Freescale data sheets for the radio we use, RX is actually higher than TX.

To monitor RFE external battery level, is this ok to wire battery + to ADC0 pin 20? What if battery voltage is higher then ADC reference?
The battery is 2 AA pack.

According to page 265 of the MC9S08GB60A Data Sheet (links to this are posted elsewhere on this site), you can go above or below the analog reference voltages by .3 volts.

Even with that, I personally would not directly connect the battery voltage to the ADC pin. I would use a resistor divider circuit.

Do a search for "voltage divider rule" and look at links like

http://en.wikipedia.org/wiki/Voltage_divider_rule
http://www.aikenamps.com/VoltageDividerRule.htm

And what is Ch8 low voltage reference and Ch9 high voltage reference? How the one or another can be used? Is there software switch?

The microcontroller used on the RF Engine actually has 10 ADC inputs, not 8. The first 8 go to external pins, and take external measurements.

The last two take internal measurements, and are useful to "sanity check" the ADC hardware and software.

[korda]

Can you specify what are the voltages on the channels on Ch8 and Ch9.
Can you specify the RFE ADC reference voltage, and if you have one?

[kbanks]

Can you specify what are the voltages on the channels on Ch8 and Ch9.

If by "can you specify the voltages" you mean "can the end user control the voltages", the answer is no.

If by "can you specify what are the voltages" you mean "can you tell me what they are connected to", then the answer is yes - Channel 8 is internally connected to the internal HREF voltage, and channel 9 is internally connected to the internal LREF voltage.

Can you specify the RFE ADC reference voltage, and if you have one?

Again I am unsure of the meaning of your question.

If you mean "can the user control this" the answer is no.

If you mean "can you tell me what they are", then HREF is the same as VCC, and LREF is the same as GND.

[korda]

Can you tell if Ch8 (HREF-VCC) is wired directly to Battery positive or there is DC/DC between battery and a VCC?
Or
Is HREF physically the same as VCC?
is BAT+ physically the same as HREF or VCC?

Are the power circuit in regards of VCC and HREF the same on all eval boards?

Note: the electrical schematics in the manual would be useful.

[kbanks]

HREF is tied to VCC on the RF Engine.

David Ewing is working on the issue of schematic distribution (Do we license this? Do we just add it to the manual?)