ESP8266 Community Forum

- Thu Oct 29, 2015 10:18 am #32554 It is difficult to see in a video how the wiring is done.
Do you have a PullUp resistor on the MCP Reset pin ? (otherwise, it can explain the randomness at power up)
Also, for the ESP itself, do you have PullUp resistors on CH_PD and RES pins ?

- Thu Oct 29, 2015 10:40 am #32558 Wow. Not sure how I missed all of this.

Basically, to answer your question(s): No. I don't have any of those things

Also, for some reason I didn't know I needed to set the REST pin on the esp8266. Is that ALWAYS need to be connected? Even when I'm flashing/programming?

I'm going to read some tutorials regarding "pull up resistors" and give this a shot again (sadly, I don't exactly know what you mean in your instructions but I'm fairly sure that I should, I've heard "pull up resistor" a lot, so I'll do a bit of reading).

Thanks Martin, I really really really appreciate it.

- Thu Oct 29, 2015 10:55 am #32560 Leaving important pins floating is never a good thing, especially on important pins such reset, it act like an antenna, which leads to unknown state.
On ESP-12, all CH_PD/RES/GPIO2/GPIO0 needs PullUps to stay at defined HIGH state while GPIO15 needs PullDown to be at LOW state for proper boot process.
Other pins are less important since they are not used by the bootloader.

- Thu Oct 29, 2015 11:44 am #32562 OK, so an update:

I think I have adding SOME of the things you said I need:

1. I added a pull up resistor to the RESET pin on the esp-01
2. I added a pull up resistor to the ch_pd pin on the eps-01 (q: I've read in a number of palces that the esp-01 should be connected directly to 3.3V??)
3. I added a pull up resistor to the RESET pin on the MCP

Questions:

1. This seems to "work" a bit more reliably now (yeah!), but it's somewhat strange because before, the second I plugged in the esp-01 into power the light would start blinking (or not blinking, or sometimes blinking, etc ). Now, if I disconnect and then plug it in, it takes a seemingly random amount of time for the light to start blinking. This isn't exactly a significantly sample size, but I just timed it twice, and the first time it took ~1 minute and 55 seconds for the light to start blinking. The second time it took 10 seconds. So actually, I'm sort of wondering if before it was doing the same thing I just wasn't waiting long enough to see if it "came on".

2. How do I add a "pull up resistor" to the GPIO 0/2 pins? They are directly connected to the SCL/SDA pins on the MCU. The other pins I "get" because they are open, so I essentially just connect them to 3.3V with a 47k resistor. But the pins that are already connected, so I' not 100% sure how to "pull up" those pins. If it's not easy to explain, please don't as I can/will figure this out via the magic of reading/youtube videos .

Thanks again!