Use this forum to chat about hardware specific topics for the ESP8266 (peripherals, memory, clocks, JTAG, programming)
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By perigalacticon
#72911 I have ordered 2 sets of ESP01 modules over the past few weeks and as far as I can see they are DOA. I am confused, because I have 8 working ESP01s that I program from the same fixtures, however the 2nd set have had absolutely no response on the serial monitor. The 2 sets of 4 are from different sellers. 4 are from an amazon seller "TBD CONTROLS" https://www.amazon.com/gp/product/B01MT6T73L/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1

4 are from Addicore https://www.addicore.com/ESP8266-ESP-01-p/130.htm.

From the packaging they appear to have been from the same manufacturer. I tried uploading at various speeds and listening on the serial monitor at all available speeds but there is absolutely no output on serial on power on or assertion of the reset pin (GND). There is no response to any AT commands. Nothing received at all on the serial monitor. I use the same fixture on my existing ESP01s and everything works fine. I use an FTDI cable, an external power supply and an 800mA 3.3v regulator, the voltage is steady.

Has anyone had a problem like this I am wondering if they are not getting destroyed during shipping. Physically they look good, just nothing on serial. On the IDE output I get

Code: Select allwarning: espcomm_sync failed
error: espcomm_open failed
error: espcomm_upload_mem failed
error: espcomm_upload_mem failed

The leds on the ESP01 never waiver, there is just a steady red led constantly on.
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By perigalacticon
#73124 Well people here's the answer, I made a mistake. I have not been using a pull up resistor on CH_PD. I've never had to before with 8 modules, but I have to with all the newer modules. The pull up fixes all the problems. Now if I could only fix these problems:

1. not starting the sketch on power on or requiring several power cycles to get it to start
2. not starting the sketch on manual reset
3. not starting the sketch after OTA upload
4. not connecting to networks
5. taking way too long to connect to network
6. not responding to OTA requests
7. OTA failing to complete upload
8. not restarting after OTA upload failure
9. requiring power cycle after failed OTA upload failure to restart
10. requiring power cycles after FTDI upload to start the sketch

IF you could clear these up it would be great.