Strange problem...

[manjh]

If you think you've seen it all, read on.

On a NodeMCU I was experimenting with a dust sensor GP2Y10 and a simple 2-line LCD display. I put together some rules, including some init messages to the LCD.
At some point I decided to swap the LCD for an OLED display that I have.
I forgot to remove the LCD commands in the rules. Should have thought of that.
After this, I rebooted the unit and it never came back alive. It keeps rebooting.
This is what I captured on the serial connection:

Code: Select all

ets Jan  8 2013,rst cause:2, boot mode:(3,7)

load 0x4010f000, len 1384, room 16 
tail 8
chksum 0x2d
csum 0x2d
v3de0c112
~ld
øªU
INIT : Booting Build nr:112
IP   : Static IP :10.0.0.206
WIFI : Connecting... 1
WIFI : Connected!
INIT : I2C
INIT : Boot OK
INIT : Normal boot
EVENT: System#Boot
ACT  : lcdcmd,clear

Exception (28):
epc1=0x4021ff9f epc2=0x00000000 epc3=0x00000000 excvaddr=0x00000008 depc=0x00000000

ctx: cont 
sp: 3fff2c90 end: 3fff32a0 offset: 01a0

>>>stack>>>
3fff2e30:  00000010 3fff2e90 3fff2e90 40222a84  
3fff2e40:  00000000 00000000 00000000 40222ad3  
3fff2e50:  3fff2264 00000010 00000000 4022008f  
3fff2e60:  00000001 00000001 00000001 402200d3  
3fff2e70:  00000000 00000001 00000000 402200e8  
3fff2e80:  00000000 00000001 00000001 402099b4  
3fff2e90:  00000000 00000000 00000000 00000001  
3fff2ea0:  4010480a 00000025 7fffffff 00000002  
3fff2eb0:  00000125 00000000 0000001f 40105ee1  
3fff2ec0:  4010376f 00080000 00000001 3fff2264  
3fff2ed0:  00000000 3fff2fa0 00002200 4000050c  
3fff2ee0:  3fffc278 4010346c 3fffc200 00000022  
3fff2ef0:  3fff2f00 00000000 00000004 3fff2fa0  
3fff2f00:  4021225c 00000030 00000008 ffffffff  
3fff2f10:  4021225c 00000000 3fff5790 ffff8000  
3fff2f20:  00000073 3fff57c0 402520ee 00000000  
3fff2f30:  00000080 3fff5798 00000000 3fff2264  
3fff2f40:  00000010 3fff3010 00000000 4010053d  
3fff2f50:  00000010 3fff3010 00000000 4010053d  
3fff2f60:  00000010 3fff3020 00000000 3fff3010  
3fff2f70:  00000010 3fff3010 3fff3010 40222a84  
3fff2f80:  3ffea2d4 00000000 3fff3010 40222ad3  
3fff2f90:  3ffea2d4 00000000 3fff3010 40222b05  
3fff2fa0:  0000000d 3fff3028 3fff3010 40222c9d  
3fff2fb0:  3fff579b 3fff3028 3fff3010 40222c9d  
3fff2fc0:  3fff5794 00000000 00000007 40223430  
3fff2fd0:  3fff577c 0000000f 00000005 3fff2264  
3fff2fe0:  00000010 3fff3070 00000000 4010053d  
3fff2ff0:  3ffea2d4 3fff30c4 00000006 40222a28  
3fff3000:  3ffea2d4 3fff30c4 00000005 3ffea2d4  
3fff3010:  00000010 3fff3070 3fff3070 40222a84  
3fff3020:  40251a64 00000006 3fff3070 40222ad3  
3fff3030:  3fff2264 00000370 00000370 4010020c  
3fff3040:  3fff31c4 00000000 3fff30d0 4010068c  
3fff3050:  3ffea2d4 00000000 3fff3180 40222a28  
3fff3060:  3fff31c4 0000000a 3fff3180 4021676a  
3fff3070:  00000000 00000000 00000000 40215f16  
3fff3080:  00000000 00000000 00000000 00000001  
3fff3090:  00000001 00000000 3fff3180 3fff3180  
3fff30a0:  00000010 3fff3138 3fff3138 40222a84  
3fff30b0:  3ffea2d4 00000000 3fff3138 40222ad3  
3fff30c0:  00000001 00000000 00000000 00000000  
3fff30d0:  00000000 00000000 00000000 00000000  
3fff30e0:  00000000 3fff31a8 00000000 4010053d  
3fff30f0:  00000010 00000001 3ffea2d4 3fff3180  
3fff3100:  3fff03ac 0000000b 3fff31c4 402073ed  
3fff3110:  00000010 3fff31a8 3fff31a8 40222a84  
3fff3120:  6364636c 632c646d 7261656c 3fff574c  
3fff3130:  0000000f 00000000 3fff5764 0000000f  
3fff3140:  00000000 3fff3180 3fff2280 00000000  
3fff3150:  00000001 00000001 40221548 3fff2280  
3fff3160:  00000001 00000000 3fff31e8 00000001  
3fff3170:  00000001 00000000 3fff31e8 4021127b  
3fff3180:  00000000 00000000 00000000 00000000  
3fff3190:  00000000 00000000 3fff440c 3fff443c  
3fff31a0:  0000000f 00000000 3fff5734 0000000f  
3fff31b0:  00000000 3fff3240 3fff4e54 0000000f  
3fff31c0:  0000000c 3fff4e3c 0000000f 0000000c  
3fff31d0:  3fff4e24 0000000f 00000000 3fff4424  
3fff31e0:  0000000f 0000000c 3fff4dfc 0000001f  
3fff31f0:  0000000c 3fff4dac 0000001f 00000013  
3fff3200:  000001ec 00000000 00000001 00000000  
3fff3210:  3fff3240 ffffffff 3fff3240 40222e08  
3fff3220:  3f0055aa 3fff32e8 3fff0e24 3fff2270  
3fff3230:  3fff1224 3fff32e8 3fff0e24 40213e11  
3fff3240:  3fff440c 0000000f 0000000b 3fff44f4  
3fff3250:  0000001f 00000012 fe00effe feefeffe  
3fff3260:  feefeffe feefeffe feefeffe feefeffe  
3fff3270:  feefeffe feefeffe feefeffe 3fff2270  
3fff3280:  3fffdad0 00000000 3fff2268 4022158c  
3fff3290:  feefeffe feefeffe 3fff2280 40100718  
<<<stack<<<

 ets Jan  8 2013,rst cause:2, boot mode:(3,7)

Before someone wonders: I was on build 148, and tried to go back a few releases to see if I can get a working system again. Had to go all the way to build 78: this gives me a working unit (no rules...).
As soon as I load a newer release, it fails again. I took the capture on build 112.

Q1: is my assumption correct? Rules causing this?
Q2: how can I get rid of this, i.e. clear the whole memory?

[manjh]

OK, I managed to destroy the evidence... cleared the memory by connecting TX/RX and restarting the unit.
Memory is now cleared and I am able to start the unit normally.

Part of me is happy because I can now move on with this unit.
But unfortunately we'll never know what caused this problem!

[manjh]

I found the cause of the problem!
After getting the ESP unit back up and running again with an OLED screen attached, I made a little mistake and submitted an LCD command via the command field in the tools tab.
This actually brought the system down and made it reboot.
I tried the same on another ESP unit in my house: same result.

This means that my original problem was indeed caused by the LCD command in the system-boot part of my rules!
And it can be reproduced easely: simple select an ESP unit without LCD attached, and send it an LCD command.
Bingo!

I suppose this is a bug?

[Shardan]

Open a Github issue?

[manjh]

Open a Github issue?

Yes, just did. Issue #581.

[manjh]

Problem was successfully reproduced by one of the developers. A fix will be made and tested.