ESP8266 Community Forum

Posted: **Sat Apr 28, 2018 1:57 am**

Hi everyone,
i wonder if somebody has already experimented my issue.
I have a ESP07 and upload a program with a FTDI USB converter.
This program works well.
If i supply the ESP07 by a LiOn battery (~4 V) everything is ok.
But if i supply it by a LiFePo4 battery (3.2V), nothing works. I have exception and stack error.

Concerning the program, i try with example programs of the librairy and the problem is the same.
Here are one the stack errors (because i don't have the same issue each time...:

Code: Select all

Exception (0):
epc1=0x4022d788 epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000000 depc=0x00000000

ctx: sys 
sp: 3ffff710 end: 3fffffb0 offset: 01a0

>>>stack>>>
3ffff8b0:  e49d9e70 d4c77b00 0008e598 8cbb5d85  
3ffff8c0:  00000000 00000000 00000001 40006545  
3ffff8d0:  00000001 00000000 00000008 3ffff922  
3ffff8e0:  400068d5 00000000 00000000 400067bc  
3ffff8f0:  00000008 00000000 00000000 00000000  
3ffff900:  4022da3d 3ffee328 00000000 40006545  
3ffff910:  3ffff923 00000000 00000000 40006545  
3ffff920:  00000000 0000000e 00000000 00000000  
3ffff930:  00000000 00000000 00000000 00000001  
3ffff940:  40227dbf 00000000 00000000 00000000  
3ffff950:  00000000 00000008 3ffff972 00000000  
3ffff960:  00000000 00000000 00000000 00000000  
3ffff970:  00004330 40228314 0000005a 0000005a  
3ffff980:  3ffee328 60009a00 3ffee34e 3fff036c  
3ffff990:  00000005 00000000 00000000 00000008  
3ffff9a0:  00000000 00000000 00000000 00000000  
3ffff9b0:  00000000 00000000 402272d8 00000202  
3ffff9c0:  00fb00f7 00f800ff 3ffee338 00000001  
3ffff9d0:  000000e8 00000000 4022a091 60009a00  
3ffff9e0:  3ffee328 60009600 3ffee384 00000000  
3ffff9f0:  3fff036c 3ffee34e 3fff0240 0000001d  
3ffffa00:  1fffffff 00000006 3ffee328 00000064  
3ffffa10:  3fff026c 00000000 00000000 00000000  
3ffffa20:  4022a723 3ffee328 3ffee328 00000000  
3ffffa30:  3ffee3d4 4022a720 3ffee328 00000000  
3ffffa40:  00000000 00000001 60000200 e8d97916  
3ffffa50:  40226303 00000000 3ffee328 00000000  
3ffffa60:  40105eae 60000e00 00000024 3fffff10  
3ffffa70:  4022b47e 3ffffa80 00000008 4021aa0a  
3ffffa80:  00000000 00000000 00000083 015ccf7f  
3ffffa90:  00000000 b20083f6 00006f80 3fff016c  
3ffffaa0:  00000000 40201b39 3fff016c 3fff016c  
3ffffab0:  3ffede9e 4022f720 00000001 00000000  
3ffffac0:  00000001 3fff016c 000002f4 003fc000  
3ffffad0:  4010564a 00000012 3ffede9e 40217593  
3ffffae0:  40217c08 60000e00 3fff016c 40217be3  
3ffffaf0:  40104e90 000003fd 00000012 60000200  
3ffffb00:  3fffff10 d937a188 8918e87c dcc6dd1a  
3ffffb10:  ffffffff ffffffff ffff0003 00000000  
3ffffb20:  3fff1500 00000228 00000001 4021b2ac  
3ffffb30:  3fff1584 00000001 3ffe8bb1 402142c8  
3ffffb40:  00030503 00010003 243ffe97 a6000000  
3ffffb50:  ff3ffe89 3cffffff b440104a b8005bf4  
3ffffb60:  003fff33 50000000 b83ffeeb 403fff33  
3ffffb70:  b83fff23 003fff33 ff000000 7cffffff  
3ffffb80:  40402033 003fff23 0d884297 c0ed205d  
3ffffb90:  f2f84e8b 94e75781 964749dd cec1d9be  
3ffffba0:  89b463d8 ac95aaf9 ffffffff ffffffff  
3ffffbb0:  ffffffff ffffffff ffff00ff ffffffff  
3ffffbc0:  0000000a 5f505345 36463338 00003130  
3ffffbd0:  00000000 00000000 00000000 00000000  
3ffffbe0:  00000000 00000000 00000000 00000000  
3ffffbf0:  00000000 00000000 00000000 00000000  
3ffffc00:  00000000 00000000 00000000 00000000  
3ffffc10:  00000000 00000000 00000000 00000000  
3ffffc20:  00000000 ffffffff ffffffff ffffffff  
3ffffc30:  ffffffff ffffffff ffffffff ffffffff  
3ffffc40:  ffffffff 000001ff ffffff04 ffff0001  
3ffffc50:  00000000 3fff1500 00000228 00000001  
3ffffc60:  4021b2ac 3fff1584 00000001 3ffe8bb1  
3ffffc70:  402142c8 3ffe9700 00000024 3fff89a6  
3ffffc80:  ffffffff 40104a3c 005bf4b4 3fff33b8  
3ffffc90:  00000000 3ffeeb50 3fff33b8 3fff2340  
3ffffca0:  3fff33b8 00000000 ffffffff 4020337c  
3ffffcb0:  3fff2340 ffffffff ffffffff ffffffff  
3ffffcc0:  ffffffff ffffffff ffffffff ffffffff  
3ffffcd0:  ffffffff ffffffff ffffffff ffffffff  
3ffffce0:  ffffffff ffffffff ffffffff ffffffff  
3ffffcf0:  ffffffff ffffffff ffffffff ffffffff  
3ffffd00:  ffffffff ffffffff ffffffff ffffffff  
3ffffd10:  ffffffff ffffffff ffffffff ffffffff  
3ffffd20:  ffffffff ffffffff ffffffff ffffffff  
3ffffd30:  ffffffff ffffffff ffffffff ffffffff  
3ffffd40:  ffffffff ffffffff ffffffff ffffffff  
3ffffd50:  ffffffff ffffffff ffffffff ffffffff  
3ffffd60:  ffffffff ffffffff ffffffff ffffffff  
3ffffd70:  ffffffff ffffffff ffffffff ffffffff  
3ffffd80:  ffffffff ffffffff ffffffff ffffffff  
3ffffd90:  ffffffff ffffffff ffffffff ffffffff  
3ffffda0:  ffffffff ffffffff ffffffff ffffffff  
3ffffdb0:  ffffffff ffffffff ffffffff ffffffff  
3ffffdc0:  ffffffff ffffffff ffffffff ffffffff  
3ffffdd0:  ffffffff ffffffff ffffffff ffffffff  
3ffffde0:  ffffffff ffffffff ffffffff ffffffff  
3ffffdf0:  ffffffff ffffffff ffffffff ffffffff  
3ffffe00:  ffffffff ffffffff ffffffff ffffffff  
3ffffe10:  ffffffff ffffffff ffffffff ffffffff  
3ffffe20:  ffffffff ffffffff ffffffff ffffffff  
3ffffe30:  ffffffff ffffffff ffffffff ffffffff  
3ffffe40:  ffffffff 04080000 001c110c 01010000  
3ffffe50:  ffffffff 00000003 ffffff00 ffffffff  
3ffffe60:  ffffffff ffffffff ffffffff ffffffff  
3ffffe70:  ffffffff ffffffff ffffffff ffff0064  
3ffffe80:  00000000 00000000 ffffffff ffffffff  
3ffffe90:  ffffffff ffffffff ffffffff ffffffff  
3ffffea0:  ffffffff ffffffff ffffffff ffffffff  
3ffffeb0:  ffffffff ffffffff ffffffff ffffffff  
3ffffec0:  ffffffff ffffffff ffffffff ffffffff  
3ffffed0:  ffffffff ffffffff ffffffff ffffffff  
3ffffee0:  ffffffff ffffffff ffffffff ffffffff  
3ffffef0:  ffffffff 0d884297 c0ed205d f2f84e8b  
3fffff00:  94e75781 964749dd cec1d9be 89b463d8  
3fffff10:  ac95aaf9 ffffffff ffffffff ffffffff  
3fffff20:  ffffffff ffffffff ffffffff ffffffff  
3fffff30:  ffffffff ffffffff ffffffff ffffffff  
3fffff40:  ffffffff ffffffff ffffffff ffffffff  
3fffff50:  ffffffff ffffffff ffffffff ffffffff  
3fffff60:  ffffffff ffffffff ffffffff ffffffff  
3fffff70:  ffffffff ffffffff ffffffff ffffffff  
3fffff80:  ffffffff ffffffff ffffffff ffffffff  
3fffff90:  ffffffff 49073c2f 71493818 19795a08  
3fffffa0:  400201e9 19065a20 ffffff00 55aa55aa

Posted: **Sat Apr 28, 2018 3:57 am**

hmmm, at least now we have proof that continued overvoltage damages the esp8266 (or at least the flash).

Posted: **Sat Apr 28, 2018 9:01 am**

Most likely you have no proper bypass capacitors added to the ESP-07. And I suspect that you are using inadequate wiring.

At 4 volts the power dip is not below what the ESP8266 needs to operate. But at 3.2 volts the dip disrupts operation. The meter can't measure the sudden drop in voltage. You are seeing the average value with the meter.

If you don't know what to do with the above information then post a picture of your setup with the lithium battery.

Posted: **Sat Apr 28, 2018 10:51 pm**

I don't have Fritzing for this moment but there is the current configuration=

VCC and GND are connected to the lithium battery with a capacitor of 22 µF
CH_EN is tied up by a resistor of 4.7 kohm
RST is directly connected to GPIO 16 by a jumper to allow deepsleep capability
RX, TX, GND are connected to FTDI USB converter to see the serial notifications.

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