ESP32 Direct coax wi-fi connection

[Jeff Addy]

I want to connect two ESP32 DevKits with an external antenna connector using coax cable. Is it possible to directly connect them without an attenuator? I have them working with two 30 Db attenuators and a T to connect a tinySA and I am getting around -25 dBm at the T. I am using ESP_NOW and Arduino for my program and have not found a way to change the TX power output. I have tried WiFi.setTxPower(WIFI_POWER_2dBm); in the setup but it doesn't change the power output when using ESP_NOW. Any help would be greatly appreciated.

[thezcx]

Which model do you use?

[Jeff Addy]

HiLetgo ESP32-DevKitC-V4 with ESP32-WROOM-32U Core Board.

[thezcx]

Remove the connector from PCB and solder mid to mid shield to any side of it. I'm using many in this way

[Jeff Addy]

Thank you for your response. Do you connect them directly or use an attenuator?

[Craige Hales]

@thezcx - Can you post a picture showing what you are doing? Sounds interesting.

I've used this on a wroom32 (pcb antenna) with a streaming wifi web socket:

Code: Select all

static int8_t const sPowers[] = {8, 20, 28, 34, 44, 52, 56, 60, 66, 72, 80};
...
        ESP_ERROR_CHECK_WITHOUT_ABORT(esp_wifi_set_max_tx_power(sPowers[p]));

The value 8 works over very short distances (10 feet maybe) and gives me a lower ADC noise than 52 to 80. I'm pretty sure the wifi tx is getting into the sensor.