user48730: As an off-Topic to my main question, regarding Robodyn's Uno+Wifi - it seems that Wifi does not work ( fail to connect and fail find any network ).
Juraj advised to use External Antenna ( did not work ) and try to make an RF calibration as shown on espressif's site. Which I fail to understand how it is done.
a) Can anyone help with RF Calibration ?
b) Might it be another reason for that ?
Guy
EDIT_1
Just to be clear, a sלetch was uploaded and executed successfully to the ESP8266 module (Basic WiFi connect and network scan ).
Edit_2


user37622: You can't do anything else with the RF calibration then to clean the flash area where it is stored. There are two reason for doing it:
First is reason to delete the RF calibration area is, if it was written by different version of Espressif SDK, including changing between AT firmware and Arduino. Then it is almost always wrong. I think they changed the data structure so some values are swapped.
Second reason is if the SDK did the calibration in wrong conditions like without antenna.
There is not much information about RF calibration. The FAQ has "Please erase the RF parameters to trigger overall calibration."
The AT firmware reference has (addresses for 4MB-C1):

blank.bin 0x3FB000 Initializes RF_CAL parameter area.
esp_init_data_default.bin 0x3FC000 Stores default RF parameter values, has to be downloaded into flash at least once. If the RF_CAL parameter area is initialized, this bin has to be downloaded too

The esp8266 Arduino core writes the data of esp_init_data_default.bin as part of the sketch's binary.
EDIT: the SDK does the 'digital calibration' at boot. it takes some microseconds. it is not done at every boot, but after some count of resets. this can be configured in the init section

48730: <p>As an off-Topic to my main <a href="https://arduino.stackexchange.com/questions/78808/robotdyns-unowifi-r3-atmega328pesp8266-32mb-flash-usb-ttl-ch340g-micro-usb?noredirect=1#comment174934_78808">question</a>, regarding Robodyn's Uno+Wifi - it seems that Wifi does not work ( fail to connect and fail find any network ).</p>
<p>Juraj advised to use External Antenna ( did not work ) and try to make an RF calibration as shown <a href="https://docs.espressif.com/projects/espressif-esp-faq/en/latest/development-environment/debugging.html?highlight=calibration#how-can-i-modify-the-default-method-of-rf-calibration-in-esp8266" rel="nofollow noreferrer">on espressif's site</a>. Which I fail to understand how it is done.</p>
<p>a) Can anyone help with RF Calibration ?</p>
<p>b) Might it be another reason for that ?</p>
<p>Guy</p>
<p><strong>EDIT_1</strong>
Just to be clear, a sלetch was uploaded and executed successfully to the ESP8266 module (Basic WiFi connect and network scan ).</p>
<p><strong>Edit_2</strong>
<a href="https://i.stack.imgur.com/sIedI.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/sIedI.jpg" alt="close up pic" /></a></p>
 37622: <p>You can't do anything else with the RF calibration then to clean the flash area where it is stored. There are two reason for doing it:</p>
<p>First is reason to delete the RF calibration area is, if it was written by different version of Espressif SDK, including changing between AT firmware and Arduino. Then it is almost always wrong. I think they changed the data structure so some values are swapped.</p>
<p>Second reason is if the SDK did the calibration in wrong conditions like without antenna.</p>
<p>There is not much information about RF calibration. The <a href="https://docs.espressif.com/projects/espressif-esp-faq/en/latest/development-environment/debugging.html?highlight=calibration#how-can-i-modify-the-default-method-of-rf-calibration-in-esp8266" rel="nofollow noreferrer">FAQ</a> has &quot;Please erase the RF parameters to trigger overall calibration.&quot;</p>
<p>The AT firmware reference has (addresses for 4MB-C1):</p>
<ul>
<li>blank.bin 0x3FB000 Initializes RF_CAL parameter area.</li>
<li>esp_init_data_default.bin 0x3FC000 Stores default RF parameter values, has to be downloaded into flash at least once. If the RF_CAL parameter area is initialized, this bin has to be downloaded too</li>
</ul>
<p>The esp8266 Arduino core writes the data of esp_init_data_default.bin as part of the sketch's binary.</p>
<p>EDIT: the SDK does the 'digital calibration' at boot. it takes some microseconds. it is not done at every boot, but after some count of resets. this can be configured in the init section</p>
