- Wed Apr 18, 2018 9:37 am
#75461
Hi, I have received some sample PCBs assembled with ESP12F modules. I've verified the power supply and the ESP12 connections and they seem to be ok. I've been able to talk with the ESP12 using AT commands, so the Rx and Tx are correctly connected. I'm able to boot it by the code in the flash (AI-Thinker), it states boot mode (3,7) or (3,0) depending if it is a power-up or a reset. I was also able to boot it in programming mode (tying GPIO0 to gnd), it states boot mode (1,7) or (1,0) depending if it is a power-up or a reset. The problem I'm facing is that I am not able to program it, Arduino states espcomm_sync_error every time I try it, I observe that the ESP12F receives several commands but never answers to Arduino, so the process never ends well (The ESP Tx led never blinks in the programming attempt, only the Rx led blinks). Also using the NodeMCU flasher tool was not able to get the node MAC addresses or to program it, like I do with other ESP12 modules, including other ESP12F modules I have. What do you think could be the problem? A bad ESP12F module that works but doesn't answer to programming commands (maybe crashes after booting from the internal bootloader)? Connecting it to putty when booting in programming mode, I only observe the boot mode line (reset cause 2, boot mode (1,0) or (1,7) as I state above). I'll try to remove it and test it on other board, but since these were professionally assembled boards in a pick and place line I was trying to avoid that until now, but all my ideas were tested.
Another test I did was to observe the Rx line on the ESP12F and noticed that it changes normally when I transmit data from putty when it is in normal mode, but it is stuck to 3.3V when it boots in bootloader mode (it only fluctuates a few millivolts below 3.3V when it receives data. This seems a bad ESP12F module, doesn't it? I've tried with two different FTDI adapters and had the same behavior.
Thanks in advance!
Fernando