You can repurpose the RX and TX pins independently: https://arduino.stackexchange.com/questions/29938/how-to-i-make-the-tx-and-rx-pins-on-an-esp-8266-01-into-gpio-pins In my project, using ESP-1 (which only exposes/breaks out GPIO0 and GPIO2), I have remapped RX (GPIO3) as an output. This allows me...

Use a Witty ESP8266 board
It has the programing part and the ESP on two separate boards, so you can use the programming circuit without having the ESP interfering with the reset sequence.

Does a solution exist on the ESP8266 to perform a Serial.swap only for Rx?
I am short on pins and need GPIO15 for another purpose.

Finally the Heltec display is working using its own driver: That driver is managing the two I2C channels, so you do not need the Wire.h library that would conflict. With auto &display = *(Heltec.display); at the beginning of setup() and at the beginning of loop(), you can use the usual display primi...

lbernstone wrote: ↑

Wed Jul 21, 2021 5:40 pm

0x78 is a common location. You can use a I2C scanner to find it. https://github.com/stickbreaker/arduino ... s/i2c_scan

Thank you, unfortunately that address does not work.
The ESP32 I2C scanner does not find any address when used with
SCL=15, SDA=4

The Heltec LoRa V1 ESP32module appears to have a distinct I2C connection to their OLED display. I tried to access the display using the standard SSD1306 librry that way: #ifdef CONTR_IS_HELTEC SSD1306Wire display(0x3c, 15, 4); //OLED 128*64 soldered #endif since they announced to use GPIO15 as SCL a...

What is the "internal switch amplifier"?

The new version 1.0.16 of ESP 32 compiler takes TLS by default! This may break e.g. communication with MQTT brokers that do not handle TLS. If you enable full debugging messages you get [V][ssl_client.cpp:265] stop_ssl_socket(): Cleaning SSL connection. [V][ssl_client.cpp:59] start_ssl_client(): Fre...

Espressif specifies: The ADC driver API supports ADC1 (8 channels, attached to GPIOs 32 - 39), That should include GPIO 37,38, logically with ADC1 and 2 respectively. The Vroom module does not expose these pins, so one have only 6 ADC inputs freely usable. (all ADC2 pins are is mainly not usable wit...

The ADC of the ESP32 has a – fully justified – bad reputation. - The advertised 12 bits are practically 9 bit +3 bit noise. - The V/ADC relation is not linear - The first 0.21V of the input (by 11dB attenuation) are ignored I am proposing here a solution to get an acceptable result despite of all th...