How to verify the 4Mbps transmission mode of the nRF54L15 series?

[Cytheria]

I noticed that the product information of the nRF54L15 series kit supports 4Mbps, but I'm unsure how to verify it. Are there any relevant examples available? I have currently tried the radio_test example, but this example doesn't show the actual data rate.

[ER!K]

Our of curiosity, did you succeed with higher throughput when using the 4Mbps phy?

[Cytheria]

yes,i used the esb sample.

[ER!K]

Thanks for following up. What throughput were you able to achieve?

[Cytheria]

3.21Mbps

[ER!K]

Nice, that's a quite decent result! You mind sharing the major tweaks/settings to achieve that? 

[Cytheria]

To obtain a timestamp, you can use the k_uptime_get() function to calculate the number of bytes received within a specific time interval.

[ER!K]

Thanks. I was more referring to the used settings when initializing/running ESD other than using ESB_BITRATE_4MBPS and setting the payload to its maximum. Did you come across some non-obvious settings which had major impact on improving throughput?

[ER!K]

Okay, I'm at 2.35Mbps with basically the below settings and a payload of 252. I tried adding CONFIG_ESB_NEVER_DISABLE_TX=y in the prf.conf and then reduce the retransmit_delay but this is throwing an error when going below 435 since there is a minimum fix-coded into esb.c (#define RETRANSMIT_DELAY_MIN 435). I reduced this in esb.c to just 1 and can then reduce the retransmit_delay in my code and this improves to around 2.8Mbps. However, I don't really like changing code in the SDK. Anyone having further clues and suggestions for improving throughput?

struct esb_config config = ESB_LEGACY_CONFIG;

config.protocol = ESB_PROTOCOL_ESB_DPL;

config.retransmit_delay = 435;

config.retransmit_count = 0;

config.bitrate = ESB_BITRATE_4MBPS;

config.event_handler = event_handler;

config.mode = ESB_MODE_PTX;

config.selective_auto_ack = true;

config.use_fast_ramp_up = true;

tx_payload.noack = true;

[ER!K]

I found that the macro ESB_CREATE_PAYLOAD(...) used by the ESB samples only support up to 63 bytes data length, hence not suitable for leveraging the full 252 bytes possible. I composed the ESB payload manually and now get decent 3.3Mbps of throughput (without acknowledge).

static struct esb_payload tx_payload = {

.pipe = 0,

.length = 252,

.data = {

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,

0,0 }

};

 

[Cytheria]

Congrats! If I recall correctly, I also modified that specific part at the time.