How to increase the esp send and receive sampling rate (AEGHB-788)

[Yaqi3707]

Hi there,

I have a problem with the CSI sampling rate between the transmitter and receiver using the../examples/csi_send & csi_recv.

I was using Rpi4 with OS: Linux raspberrypi 6.6.31+rpt-rpi-v8 #1 SMP PREEMPT Debian 1:6.6.31-1+rpt1 (2024-05-29) aarch64 GNU/Linux

My ESP-idf is: ESP-IDF v5.4-dev-1873-g41dd1a351b

From the transmitter, I set up 20000 loops for the esp_send function and increased the #define CONFIG_SEND_FREQUENCY 50000. I also set up system time to measure the total time cost. From the output of the terminal, it seems these 20000 packets have been sent in 15~16 seconds. ( My transmitter code tx.txt )

However, the receiver only captured around 200 data. I have increased the serial baud rate to 3000000 in the csi_data_read_parse.py. Based on the captured ID in the CSV file, it seems multiple packets dropped frequently. (Below is the CSV of my collected data) output18.csv

My two transmitters and receivers are placed stationarily and right next to each other in a quiet office room. Such massive packets loss is unexpected. (By the way, I changed my esp32 to esp32s3 from my last posted issue, I want to implement the FTM example later.)

Therefore, I am concerned with two questions:

1. How can I improve the sampling rate so that my receiver can collect 800~1000 pk/s?

2. Is there any way to stabilize the data captured by the receiver? In other words, how can I make the receiver capture most of the consecutive CSI data?

Sincerely appreicate any comments and guidance.

[MacChu0315-Espressif]

Hi，#135 and #173 may help, and you can try to increase the espnow rate.

[Yaqi3707]

Hi there, thanks for providing the information but I have tried the approaches you mentioned in those two issues. I previously increased the serial baud rate to 3000000 in the receiver, disabled the wait function in sender, and I attempted to modify the transmission rate in the sender too.

The problem I am stuck with the sender is that I followed the recommendation to modify the transmission rate function:

static const uint8_t CONFIG_CSI_SEND_MAC[] = {0x1a, 0x00, 0x00, 0x00, 0x00, 0x00};
...

static void wifi_init()
{
    ...
    // ESP_ERROR_CHECK(esp_wifi_config_espnow_rate(ESP_IF_WIFI_STA, WIFI_PHY_RATE_MCS7_SGI));

    if (esp_now_init() != ESP_OK) {
        ESP_LOGE("ESP-NOW","Error initializaing ESP-NOW");
        return;
    }

    esp_now_rate_config_t rate_config = {
        .phymode = WIFI_PHY_MODE_11G,
        .rate = WIFI_PHY_RATE_MCS7_SGI,
        .ersu = false,
        .dcm = false
    };

    ESP_ERROR_CHECK(esp_now_set_peer_rate_config(CONFIG_CSI_SEND_MAC, &rate_config));
    ...
}

However, the system keeps crashing and rebooting after I rebuilt and reflashed.

I tried to change the parameters of .phymode = WIFI_PHY_MODE_HT40 and .rate = WIFI_PHY_RATE_54M referred from esp_now.h and esp_wifi_types_generic.h but none of my attempts worked.

I truly appreciate if you could provide more information and assistance on this problem.

Meanwhile, as I increased the baud rate from the receiver, why do I still receive massive "element number is not equal" and "data is incomplete"? Is this the direct problem that causes me having serious CSI data loss from the receiver side? And how can I get consecutive data without any drop as you showed in #135?

[Yaqi3707]

Hi, @MacChu0315-Espressif Sorry for the interruption. Could you provide me more hints on how I can resolve this issue so that I can have the identical high-frequency sampling rate without any packet loss as you did in #135 ?

Thank you very much for your guidance and assistance!

[MacChu0315-Espressif]

hi @Yaqi3707, just for reference and simple proof of feasibility, I only made these changes on the basis of the original procedure:

[Yaqi3707]

Thank you very much. I attempted to redirect the output from the terminal but it still contained many system commands. I will try to use the SD card to write all the data into a local file as quickly as possible.