ANT Forum

I'd like to use sleep & suspend function.
I have two stations :
1.Unit station with 3 ANT sensors.
2.PC station which get the data from the unit station.

The problem is I don't know if the time is enough to do 2 actions in the period of time when the station is awake:

1.the first action is reading the data from 3 ANT sensors.
2.the second acion is sending the collected data from the staion
and transmit it to PC station.

Can I know to how many time the sations should be awake in order to to collect the data from the sensors & sending them to the PC unit?

Thanks
Yaniv      

Does your whole station need to "sleep" or do you mean just utilizing the sleep/suspend states of ANT?

Reading through the "Getting Started with ANT Development in Embedded Systems" thread and particularly the "AN13 Power States" application note would provide the best context here.

The ANT Radio will automatically switch from Sleep state to Active state when channel activity occurs and then switch back to sleep while the sleep line is asserted. "Channel activity" includes receiving any messages from any open channels.

Suspend state will cause any open channels to close, which means those channels will need to re-pair with any sensors they were connected and that can take up to 30 seconds with a 4 Hz sensor in worst case acquisition time. Suspend is also not necessarily the lowest power state, but is more intended for compatibility for USB and/or as a radio reset tool.

Most ANT+ sensors broadcast sensor data at ~4Hz, although some ANT+ profiles allow for lower receive rates to reduce slave power consumption. This means you would see a sensor message at ~12 Hz for 3 sensors at a full ~4Hz receive rate each. This assumes even spacing between sensor messages however which is unlikely but it does mean the largest time gap between messages could be ~83.33 ms.

Cheers      

If there is a option in which all the unit sleep and wake up only when ant in sending data it's better because of the power consumption.
I think I can do it by sending sleep command to the microcontroller. Am I write ro wrong ?


My questions is due to those docs you mentioned.
(After reading the application notes I have more open isues.)      

Sleep differs between SPI and UART. Sleep using UART is not a command but a control line/pin which can be asserted and de-asserted when using UART to communicate between ANT and your host MCU which is described in the "Interfacing with ANT General Purpose Chipsets and Modules" document. The Sleep pin in UART tells ANT it can turn off the serial port when it is unneeded thus saving power.

In SPI state transitions are generally automatic except for AP2's "Deep Sleep" which is also available on the UART.

However, AP2 does offer a "Deep Sleep" state designed for long durations between activity as it causes a full reset of the AP2, but in this mode AP2 will only draw ~0.5uA. That state is entered through a command specific to the AP2.

The Power Estimator can calculate the power draw for your use case and can be found here.

I would recommend trying to mock up your system using an ANT USB Stick and ANTware II which has a full feature UI for ANT development.