ESP8266 HW requirements and exception 28

[SoCalDude]

I am new to this SDK and I am struggling to understand the HW requirements. I have been searching high and low for this error at no avail. I have two NodeMCU based boards, where one works and the other throws exception 28.  From understanding, the boards should be very similar.

This device works:

NodeMCU V3 LoLin

Manufacturer: e0

Device: 4016

This device fails:

Geekcreit NodeMcu

https://www.banggood.com/Geekcreit-Doit-NodeMcu-Lua-ESP8266-ESP-12E-WIFI-Development-Board-p-985891.html

Manufacturer: c8

Device: 4016

I have several of these boards and some say ESP8266MOD and others say 2AL3B-ESP-F. None of them works.

The error I get on the second board:

Fatal exception (28): 

epc1=0x4000228b, epc2=0x00000000, epc3=0x00000000, excvaddr=0x000000b5, depc=0x00000000

My understanding is that exception 28 is a memory exception (working outside valid range).

Can anyone point me to documentation that can help me shed some light on whats wrong.

[SoCalDude]

Sigh, maybe more users would have success with the SDK if you used default values accepted by most devices:
# Flash mode, valid values are same as for esptool.py - qio,qout,dio.dout

FLASH_MODE ?= qio

 

I suggest changing this to dio