I am currently playing with esp8266. It is connected to arduino via software COM port. Arduino is sending AT commands and esp is sending responses back. The problem is that small responses look absolutely normal but longer ones are kind of damaged. First I thought this was because poor wiring but problem remained after correcting it. Also long responses are always corrupted after certain point and there is not absolute garbage but something looking slightly like correct thing:
AT+CWLAP
+CWLAP:(3,"MGTS_GPON_1936",-81,"94:4a:0c:44:8d:58",0,23,0)
+CWLAP:("::,C"N7:e,Ar8":,C""::,C"-2:0:O-ea,Aa":c,C"5::0LG8,f9):P-9:3Lv8:5,AT68d1
"9":"
458e1
AT+CWLAP
+CWLAP:(4,"Vikus",-60,"f4:6d:04:a0:ee:36",1,40,0)
+CWLAP:(3,"NURIK":55Ae4,803WM_205)PS,30):_,37,Ae9e13+,s-0e0PR,453LT9":,):_"8:1+,"::,+T"::,+,"5:3
busy s...
Recv 4 bytes
SEND OK
+IPD,166:<html>
<head><title>400 Bad Request</title></heaor>r e/
e<<tS
After replacing power supply, arduino, esp module and load capacitor things not changed:
AT+CIPSTART=
"UDP","time1.google.c⸮Kb⸮⸮⸮j
0,CONNECT
OK
AT+CIPSE
ND=48
OK
>
Secv 48 cytes
SE
ND OK
+RE⸮⸮⸮⸮"
⸮
AT+CWLAP
+CWLAP:(3,"NUR
IK",-74,"38:2c:4a:98:85:4f",1,0,0)
+CWLAP:(4,"MGT_P96,4":8b:::
8"18⸮⸮⸮*A⸮B⸮b⸮U⸮⸮͡⸮⸮⸮ʲ⸮⸮%⸮х⸮⸮⸮bkʂb2⸮⸮⸮⸮*⸮颊҂⸮Ҫ⸮b⸮b⸮
Ғ*⸮⸮bb⸮b⸮Jj
+CWLP3"oOK0"7,04:::8a080
⸮*A⸮B⸮b⸮⸮k⸮͉bj⸮b2Ѳ
The reason is Arduino's Software serial can't properly work on 115200 baud rate needed to communicate to esp8266. To fix this you have to send command AT+UART_DEF=9600,8,1,0,0 to change esp baud rate and after that change SoftwareSerial speed to 9600.