ESP8266 Community Forum

- Thu Oct 08, 2015 1:40 pm #30896 i2c scanner didn't bring up any of my 3 modules, but 2 of them work...

- Thu Oct 08, 2015 2:16 pm #30902 Did you try the "autospeed" only or all speeds manually too?
Some of these sensors don't work at all speeds (on ESP), some have special sesitivity on states of their pins on Power-up (sometimes conflicting with the needs of limited i/o ESP-01).

I finally have an AM2321 and SSD1306 working on the same i2c on a ESP-01 but it was struggle to get there coming from an arduino mini pro ...

What about the powersupply? Does your breakout have a seperate regulator? Arduino usually are 5V, the sht20 3.3V only.

- Fri Oct 09, 2015 5:24 am #30941 Well this is interesting. If I de-power the unit then plug it back in and run the multispeed scanner, it finds all 3 devices on the first run. When I run it again I see 2 devices, then 0 and they never respond again. The happy thing is that this is reproducible! It seems to happen the same way every time. A board reset has no effect - only power cycling. Must be poisoning the bus somehow...

I'll send a board to someone on the dev team if you need something to test with to get this fixed - https://dl.dropboxusercontent.com/u/157 ... 9%20PM.jpg

Last edited by Daemach on Fri Oct 09, 2015 6:30 am, edited 1 time in total.

- Fri Oct 09, 2015 6:29 am #30942 More info - the first run completes in 142ms, the second in 560ms and the third+ in 1500ms... This is also reproducible.