Why can't I use CODED PHY in ipsp example?

RE: Why can't I use CODED PHY in ipsp example?

Susheel Nuguru — Thu, 26 Apr 2018 10:59:06 GMT

Sorry for late reply, where did it cause fatal error?
BLE_GAP_EVENT_LENGTH_DEFAULT with 240 and did not get any errors and it worked just fine

RE: Why can't I use CODED PHY in ipsp example?

Elissa — Fri, 20 Apr 2018 00:29:40 GMT

Oh I misunderstand the code.... IPSP example does not use the parameter, NRF_SDH_BLE_GAP_EVENT_LENGTH, instead, it use

#define BLE_GAP_EVENT_LENGTH_DEFAULT (3)

However, when I tried to change the value, 3, it goes to fatal error....

I use 247 as a MTU size in config file.

RE: Why can't I use CODED PHY in ipsp example?

Susheel Nuguru — Thu, 19 Apr 2018 13:01:06 GMT

what is the MTU size you are using? after increasing the event length, is it the same error number?

RE: Why can't I use CODED PHY in ipsp example?

Elissa — Thu, 19 Apr 2018 10:08:57 GMT

Unfortunately, it didn't work....

RE: Why can't I use CODED PHY in ipsp example?

Susheel Nuguru — Thu, 19 Apr 2018 08:06:11 GMT

The documentation is saying the reason for this error

* @retval ::NRF_ERROR_RESOURCES The connection event length configured for this link is not sufficient for the combination of
* @ref ble_gap_phys_t::tx_phys, @ref ble_gap_phys_t::rx_phys, and @ref ble_gap_data_length_params_t.
* The connection event length is configured with @ref BLE_CONN_CFG_GAP using @ref sd_ble_cfg_set.
* @retval ::NRF_ERROR_BUSY Procedure is already in progress or not allowed at this time. Process pending events and wait for the pending procedure to complete and retry.
*
*/
SVCALL(SD_BLE_GAP_PHY_UPDATE, uint32_t, sd_ble_gap_phy_update(uint16_t conn_handle, ble_gap_phys_t const *p_gap_phys));

This means that you need to increase the event length for your connection to accomodate the coded phy transmission as it take atleast 8 times more time to transmit than a normal 1M non coded phy transmission of your packet.

You can change the event length in your sdk_config.h file NRF_SDH_BLE_GAP_EVENT_LENGTH. Increase the value to maybe 320 if this is the only connection you have.

RE: Why can't I use CODED PHY in ipsp example?

Elissa — Thu, 19 Apr 2018 05:32:49 GMT

I add phy change to ipsp initiator, too, of course. and I use same device ans same version of SDK to initiator.

sd_ble_gap_phy_update returns 13, operation time out or not enough resources for operation

RE: Why can't I use CODED PHY in ipsp example?

Susheel Nuguru — Wed, 18 Apr 2018 18:28:28 GMT

probably the peer is not configured to support coded phy . Also check if the sd_ble_gap_phy_update call returned with any errors for coded phy

RE: Why can't I use CODED PHY in ipsp example?

Elissa — Wed, 18 Apr 2018 10:40:28 GMT

There was no error, and I could not get BLE_GAP_EVT_PHY_UPDATE event. Using 1Mbps and 2Mbps PHY, I successfully get BLE_GAP_EVT_PHY_UPDATE.

RE: Why can't I use CODED PHY in ipsp example?

Susheel Nuguru — Wed, 18 Apr 2018 10:34:47 GMT

it should work, do you get any errors or asserts? what do you that you could not change to coded phy? do you get BLE_GAP_EVT_PHY_UPDATE event after the phy update request?