ANT Forum

Hi-

We have an application running on the Nordic nRF52382 with the S332 v2.00 stack. We've noticed when we have a BLE peripheral and ANT connection active concurrently, that we observe a significant increase in RX FAILures on the ANT channel. The ANT channel period is 17msec and the BLE connection period is 24 msec. If the BLE connection is dropped, the RX FAILures decrease significantly.

Can the radio/Softdevice run at these connection intervals concurrently?

Thanks!      

Just a little more info. We are sending ANT broadcast packets from the device running the S332 stack and using ANTware to sniff the air. ANTware is reporting RX FAILures when broadcast messages should be sent. The RX FAILures occur frequently while the BLE connection is active. When the BLE connection is disconnected, ANTware displays the expected ANT broadcast messages.      

...and a little more info..

We are using the nRF52832 with S332 v2.0 of the stack. We have recently been testing concurrent operation of a BLE peripheral connection and an ANT bidirectional master. The specifics are listed below:

BLE
Connection Interval (min): 24msec
Connection Interval (max): 24msec
Notification period: 250msec
# of notifications enabled: 12

ANT
RF Frequency: 2.477 MHz
Message rate: 59.04Hz
Burst transmission of 4 payload packet

Using ANTWare II and an ANT USB dongle we monitored the ANT master transmissions first with no BLE peripheral connection to get a baseline. Then we added the BLE peripheral connection concurrent with ANT (allowing our control processor to continue to update data for the radio to transmit via the UART interface). Finally, we halted the control processor from sending data to the radio once both protocols were operating.

Case 1: ANT bidirectional master only with transmit data updates from control processor

Sniffer produced near-error free (e.g., almost no receive errors) reception of master data

Case 2: ANT bidirectional master and BLE peripheral with transmit data updates from control processor

Sniffer produced enough errors that very few 4 packet bursts were received

Case 3: ANT bidirectional master and BLE peripheral with NO transmit data updates from control processor

No discernable difference from performance seen in case 2.

Could you advise on the following:

1. Have concurrency improvements been made in S332 since v2.0?
2. Are there any guidelines that must be followed in order to minimize the impact of concurrent operation?
     

One more data point....Restricting the BLE peripheral connection interval to 100msec significantly reduced the number of EVENT_RX_FAIL events being observed on the ANT sniffer.