Serial dumping _VMDPR (Really unknown error please help!)

Using Arduino Programming Questions
1

Ok so i was just programming trying to do some serial to serial com with my rasp pi and my ATmega328-PU and I think i might have screwed something up.

when even the most basic of program

void setup()
{
Serial.begin(115200);
}

void loop()
{
Serial.println("test");
}

it spams stuff like this endlessly when i watch its serial in putty or anything

VMDPR_|3:0:|258:248:245:239:231:287:|1547|VMDPR
VMDPR|3:0:|254:253:251:246:238:245:|1547|VMDPR
VMDPR|3:0:|244:246:249:250:246:276:|1547|VMDPR
VMDPR|3:0:|250:251:251:248:237:222:|1547|VMDPR
VMDPR|3:0:|246:248:247:251:242:219:|1547|VMDPR
VMDPR|3:0:|211:217:221:223:215:155:|1547|VMDPR
VMDPR|3:0:|207:211:214:218:217:158:|1547|VMDPR
VMDPR|3:0:|155:163:175:187:201:182:|1547|VMDPR
VMDPR|3:0:|160:163:167:177:194:191:|1547|VMDPR
VMDPR|3:0:|168:168:169:172:187:192:|1547|VMDPR
VMDPR|3:0:|174:173:173:173:184:190:|1547|VMDPR
VMDPR|3:0:|175:176:176:175:183:189:|1547|VMDPR
VMDPR|3:0:|178:179:179:178:173:190:|1547|VMDPR
VMDPR|3:0:|181:181:181:180:179:188:|1547|VMDPR
VMDPR|3:0:|182:184:184:184:180:184:|1547|VMDPR
VMDPR|3:0:|162:164:175:184:195:241:|1547|VMDPR
VMDPR|3:0:|166:166:170:177:190:246:|1547|VMDPR
VMDPR|3:0:|171:170:171:174:185:245:|1547|VMDPR
VMDPR|3:0:|199:195:195:199:215:313:|1547|VMDPR
VMDPR|3:0:|203:200:196:200:209:309:|1547|VMDPR
VMDPR|3:0:|202:201:200:201:208:306:|1547|VMDPR
VMDPR|3:0:|200:200:201:202:207:304:|1547|VMDPR
VMDPR|3:0:|198:200:199:202:206:303:|1547|VMDPR
VMDPR|3:0:|196:196:200:202:206:303:|1547|VMDPR
VMDPR|3:0:|196:197:199:201:207:302:|1547|VMDPR
VMDPR|3:0:|196:196:198:200:206:301:|1547|_VMDPR

2

How did you wire it up? The PI runs at 3.3v and the Arduino runs at 5v so I assume you ran it through a converter. There is one example on the web where someone ran it though a CD4050. See the page here Raspberry Pi and Arduino via GPIO UART | andremiller.net

Assuming you did not directly connect them I am unsure what these values are supposed to mean. They aren't ASCII values because they are larger than 8 bit chars (values > 255).