ESP8266 Community Forum

- Sun Sep 25, 2016 10:04 am #55677 CH_PD should not be left floating, it needs to be attached to VCC.
Baudrate is irrelevant since the internal bootloader determine it automatically, therefore 115200 should work without any problems.

- Sun Sep 25, 2016 11:53 am #55681

It should be not enough power from FTDI to power ESP, so yeah only from external source.
Thanks for the tips : ). Baud-rate also is important, although with ch_pd floating i was able to flash esp with any baud-rate, only when uploading code with ESPlorer it works with the certain baudrate...
Does anyone know how to determine correct baud-rate for the chip? Or does everyone going random on that?

If I disconnect CH_PD/CHIP_EN (PIN 7 ESP8266) from the 5K pull-up the Espressif tool can't talk to the device. From the ESP8266 hardware guide: Chip Enable. High: On, chip works properly; Low: Off, small
current.
How you can get your device to function without pulling that pin to Vcc is strange to say the least since every drawing and spec sheet from Espressif shows pulling the pin high to enable the device, period. As it stands I can get ESP8266-201/01 devices to program intermittently using the Espressif tool but not NodeMCU tool, the NodeMCU finishes but the code will not run. Check out my progress viewtopic.php?f=9&t=820&p=55642#p55642 as I get time to trouble shoot this. My setup is a M102 breadboard with the standalone power supply, FTDI wired RTS to RST, GPIO0 to GND for programming and CHIP_EN pulled high with a 5K resistor.

- Sun Sep 25, 2016 3:12 pm #55688 From reading around, the chip is supposed to auto-detect the baud rate...and the esptool.py code assumes that. However, there are comments elsewhere that suggest that some versions of the chip may not do that - or may not do it correctly, so either 9600 or 115200 may be being assumed. I dunno about that, the boards I bought from some no-name place in China for $2 a piece do auto-detect the baud rate...so I have no actual evidence to the contrary.

As for power, I've been testing my IoT stuff (ported from RaspberryPi Zero) using a couple of AA batteries - which seems to work great - but I just bought a bunch of rechargeable 3.7v 650 mAh batteries to test with...the kind that are used in cheap drone aircraft. Those are tiny, lightweight, and insanely cheap in bulk.

- Mon Sep 26, 2016 7:43 am #55711

How you can get your device to function without pulling that pin to Vcc is strange to say the least since every drawing and spec sheet from Espressif shows pulling the pin high to enable the device, period.

Is it possible that there is an internal pullup on that pin - so disconnecting it allows it to float high?