ESP8266 Community Forum

- Fri Mar 08, 2019 10:55 am #80974 Hi!

I am quite new to this stuff, so might ask really stupid questions.

I have a setup that I just can not get to work.

ESP-01
TMP275

Both running 3.3v from same source.

I have connected the SDA to GPIO0 and SCL to GPIO2 and get no data out.

I have tested the same code with Uno to A4 & A5 pins and its working fine, so sensor is working.
(0x48 address).

What on earth I need to do to fire this baby up?

I have tried also using 330Ohm resistors inline with the SDA/SCL + added 3k3-10k pullup resistors to VCC.

Could it be that I have fried the GPIO pins at some point that they do not work anymore as they should?

I tested the GPIO2 pin with DHT11 and its working with it as its PWM?

In code I used the wire.begin(0, 2) so as by documentation it should work..

When I try to boot the ESP, if either of the SDA/SCL is connected the ESP crashes.

Can someone elaborate how to to do this?

Thank you!

- Sun Mar 10, 2019 4:11 am #80997 in general it should work, I use the bme280 in same setup.
obviously the TMP275 has non-optimal behaviour during power-on and pulls sda and/or scl low.
on esp-01 there is not much you can do, maybe reconfig rx/tx ...

- Mon Mar 11, 2019 12:03 am #81031 I got it working! But..

I have 3 sensors that I would like to have running at the same time.

TMP275 measuring outdoors temp (I need this as the DHT11 does not go below zero)
DHT11 to measure indoor temp/humidity
DHT11 to measure outdoor humidity

I think I need to use interrupts here, but how do I do that?

(I face the issue that if I connect the DHT to pin GPIO 14 (the physical pin 9 /MTMS) the code will not run).

Yes, i have soldered wire to pin9 and tried to use DHT pin as 14 in the code. (defined the pin as input)

The flash is running in DIO mode, so this pin should be free?

I am sending the data to Blynk by reading the serial data to virtual pins.

I know that I could build 3 setups and use the different virtual pins for each and combine them in blynk,

but that would be waste of 3 separate esp´s.

Any help with this is much appreciated. Maybe some sketch that I could work to suite my purposes?

Pete

- Fri Mar 15, 2019 11:01 pm #81140 Anyone?