Is it possible to join a UART twice?

D

de1m2017-02-09 17:55:20

Electronics

de1m, 2017-02-09 17:55:20

I have an esp8266 and a co2 sensor is already connected to its TX / RX outputs, but the esp8266 is also programmed through these two ports.
Can I additionally connect my programmer to this output?
The goal is that when I insert all this into the case, it would be possible to change the firmware, how is this generally done correctly?

Reply

Answer the question

In order to leave comments, you need to log in

3 answer(s)

V

vaut, 2017-02-09
@vaut

Are jumpers that will connect and disconnect sensors suitable for you?

A

Armenian Radio, 2017-02-09
@gbg

Quite right - to pour the firmware over the air, but this must be thoroughly programmed.
Randomly connecting the programmer in parallel with the CO2 sensor is undesirable, the sensor will interfere with the programmer's operation. Also note that to flash the ESP8266, you need to apply LOG_0 to GPIO_0.
You can try flashing without powering the sensor.

A

AntHTML, 2017-02-09
@anthtml

Huart lines can have many receivers but only one transmitter.
Accordingly, you need to exclude the possibility of wedging in the second transmitter, i.e. during programming, de-energize the TX pin of the sensor from the line. How you implement it, a jumper on the TX line or on the sensor power is already your right.