Trying to program custom ATMEGA328 U-TH Board

[bkellett]

I had someone convert a schematic I had tested/prototyped with an arduino nano and wiz5500 board, along with some IO to a custom PCB. I now finally have my custom PCB and am trying to program it, eventually aiming to connect it to the Blynk cloud. I am having trouble programming however. I tried following this guide using an Arduino Mega I have lying around.

My pin connections between my Mega board and target are as below:

Mega Pin 51 --> MOSI of Target ICSP Header
Mega Pin 50 --> MISO of Target ICSP Header
Mega Pin 52 --> SCK of Target ICSP Header
Mega Pin 10 --> Reset of Target ICSP Header

The target board is powered by a 12V DC source which steps down to 5V and 3.3V.

The code I am using is below. My error is:

avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x03
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x03
avrdude: ser_send(): write error: sorry no info avail
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x03
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x03
Error while burning bootloader.

I have set my programmer mode to "Arduino as ISP". My mega board just has the blink example loaded onto it at the moment.

// ArduinoISP
// Copyright (c) 2008-2011 Randall Bohn
// If you require a license, see
// https://opensource.org/licenses/bsd-license.php
//
// This sketch turns the Arduino into a AVRISP using the following Arduino pins:
//
// Pin 10 is used to reset the target microcontroller.
//
// By default, the hardware SPI pins MISO, MOSI and SCK are used to communicate
// with the target. On all Arduinos, these pins can be found
// on the ICSP/SPI header:
//
//               MISO °. . 5V (!) Avoid this pin on Due, Zero...
//               SCK   . . MOSI
//                     . . GND
//
// On some Arduinos (Uno,...), pins MOSI, MISO and SCK are the same pins as
// digital pin 11, 12 and 13, respectively. That is why many tutorials instruct
// you to hook up the target to these pins. If you find this wiring more
// practical, have a define USE_OLD_STYLE_WIRING. This will work even when not
// using an Uno. (On an Uno this is not needed).
//
// Alternatively you can use any other digital pin by configuring
// software ('BitBanged') SPI and having appropriate defines for PIN_MOSI,
// PIN_MISO and PIN_SCK.
//
// IMPORTANT: When using an Arduino that is not 5V tolerant (Due, Zero, ...) as
// the programmer, make sure to not expose any of the programmer's pins to 5V.
// A simple way to accomplish this is to power the complete system (programmer
// and target) at 3V3.
//
// Put an LED (with resistor) on the following pins:
// 9: Heartbeat   - shows the programmer is running
// 8: Error       - Lights up if something goes wrong (use red if that makes sense)
// 7: Programming - In communication with the slave
//

#include "Arduino.h"
#undef SERIAL


#define PROG_FLICKER true

// Configure SPI clock (in Hz).
// E.g. for an ATtiny @ 128 kHz: the datasheet states that both the high and low
// SPI clock pulse must be > 2 CPU cycles, so take 3 cycles i.e. divide target
// f_cpu by 6:
//     #define SPI_CLOCK            (128000/6)
//
// A clock slow enough for an ATtiny85 @ 1 MHz, is a reasonable default:

#define SPI_CLOCK 		(1000000/6)


// Select hardware or software SPI, depending on SPI clock.
// Currently only for AVR, for other architectures (Due, Zero,...), hardware SPI
// is probably too fast anyway.

#if defined(ARDUINO_ARCH_AVR)

  #if SPI_CLOCK > (F_CPU / 128)
    #define USE_HARDWARE_SPI
  #endif

#endif

// Configure which pins to use:

// The standard pin configuration.
#ifndef ARDUINO_HOODLOADER2

  #define RESET     10 // Use pin 10 to reset the target rather than SS
  #define LED_HB    9
  #define LED_ERR   8
  #define LED_PMODE 7

  // Uncomment following line to use the old Uno style wiring
  // (using pin 11, 12 and 13 instead of the SPI header) on Leonardo, Due...

  #define USE_OLD_STYLE_WIRING

  #ifdef USE_OLD_STYLE_WIRING

    #define PIN_MOSI	51
    #define PIN_MISO	50
    #define PIN_SCK		52

  #endif

  // HOODLOADER2 means running sketches on the ATmega16U2 serial converter chips
  // on Uno or Mega boards. We must use pins that are broken out:
#else

  #define RESET     	4
  #define LED_HB    	7
  #define LED_ERR   	6
  #define LED_PMODE 	5

#endif

// By default, use hardware SPI pins:
#ifndef PIN_MOSI
  #define PIN_MOSI 	MOSI
#endif

#ifndef PIN_MISO
  #define PIN_MISO 	MISO
#endif

#ifndef PIN_SCK
  #define PIN_SCK 	SCK
#endif

// Force bitbanged SPI if not using the hardware SPI pins:
#if (PIN_MISO != MISO) ||  (PIN_MOSI != MOSI) || (PIN_SCK != SCK)
  #undef USE_HARDWARE_SPI
#endif


// Configure the serial port to use.
//
// Prefer the USB virtual serial port (aka. native USB port), if the Arduino has one:
//   - it does not autoreset (except for the magic baud rate of 1200).
//   - it is more reliable because of USB handshaking.
//
// Leonardo and similar have an USB virtual serial port: 'Serial'.
// Due and Zero have an USB virtual serial port: 'SerialUSB'.
//
// On the Due and Zero, 'Serial' can be used too, provided you disable autoreset.
// To use 'Serial': #define SERIAL Serial

#ifdef SERIAL_PORT_USBVIRTUAL
  #define SERIAL SERIAL_PORT_USBVIRTUAL
#else
  #define SERIAL Serial
#endif


// Configure the baud rate:

#define BAUDRATE	19200
// #define BAUDRATE	115200
// #define BAUDRATE	1000000


#define HWVER 2
#define SWMAJ 1
#define SWMIN 18

// STK Definitions
#define STK_OK      0x10
#define STK_FAILED  0x11
#define STK_UNKNOWN 0x12
#define STK_INSYNC  0x14
#define STK_NOSYNC  0x15
#define CRC_EOP     0x20 //ok it is a space...

void pulse(int pin, int times);

#ifdef USE_HARDWARE_SPI
#include "SPI.h"
#else

#define SPI_MODE0 0x00

#if !defined(ARDUINO_API_VERSION) || ARDUINO_API_VERSION != 10001 // A SPISettings class is declared by ArduinoCore-API 1.0.1
class SPISettings {
  public:
    // clock is in Hz
    SPISettings(uint32_t clock, uint8_t bitOrder, uint8_t dataMode) : clockFreq(clock) {
      (void) bitOrder;
      (void) dataMode;
    };

    uint32_t getClockFreq() const {
      return clockFreq;
    }

  private:
    uint32_t clockFreq;
};
#endif  // !defined(ARDUINO_API_VERSION)

class BitBangedSPI {
  public:
    void begin() {
      digitalWrite(PIN_SCK, LOW);
      digitalWrite(PIN_MOSI, LOW);
      pinMode(PIN_SCK, OUTPUT);
      pinMode(PIN_MOSI, OUTPUT);
      pinMode(PIN_MISO, INPUT);
    }

    void beginTransaction(SPISettings settings) {
      pulseWidth = (500000 + settings.getClockFreq() - 1) / settings.getClockFreq();
      if (pulseWidth == 0) {
        pulseWidth = 1;
      }
    }

    void end() {}

    uint8_t transfer(uint8_t b) {
      for (unsigned int i = 0; i < 8; ++i) {
        digitalWrite(PIN_MOSI, (b & 0x80) ? HIGH : LOW);
        digitalWrite(PIN_SCK, HIGH);
        delayMicroseconds(pulseWidth);
        b = (b << 1) | digitalRead(PIN_MISO);
        digitalWrite(PIN_SCK, LOW); // slow pulse
        delayMicroseconds(pulseWidth);
      }
      return b;
    }

  private:
    unsigned long pulseWidth; // in microseconds
};

static BitBangedSPI SPI;

#endif

void setup() {
  SERIAL.begin(BAUDRATE);

  pinMode(LED_PMODE, OUTPUT);
  pulse(LED_PMODE, 2);
  pinMode(LED_ERR, OUTPUT);
  pulse(LED_ERR, 2);
  pinMode(LED_HB, OUTPUT);
  pulse(LED_HB, 2);

}

int ISPError = 0;
int pmode = 0;
// address for reading and writing, set by 'U' command
unsigned int here;
uint8_t buff[256]; // global block storage

#define beget16(addr) (*addr * 256 + *(addr+1) )
typedef struct param {
  uint8_t devicecode;
  uint8_t revision;
  uint8_t progtype;
  uint8_t parmode;
  uint8_t polling;
  uint8_t selftimed;
  uint8_t lockbytes;
  uint8_t fusebytes;
  uint8_t flashpoll;
  uint16_t eeprompoll;
  uint16_t pagesize;
  uint16_t eepromsize;
  uint32_t flashsize;
}
parameter;

parameter param;

// this provides a heartbeat on pin 9, so you can tell the software is running.
uint8_t hbval = 128;
int8_t hbdelta = 8;
void heartbeat() {
  static unsigned long last_time = 0;
  unsigned long now = millis();
  if ((now - last_time) < 40) {
    return;
  }
  last_time = now;
  if (hbval > 192) {
    hbdelta = -hbdelta;
  }
  if (hbval < 32) {
    hbdelta = -hbdelta;
  }
  hbval += hbdelta;
  analogWrite(LED_HB, hbval);
}

static bool rst_active_high;

void reset_target(bool reset) {
  digitalWrite(RESET, ((reset && rst_active_high) || (!reset && !rst_active_high)) ? HIGH : LOW);
}

void loop(void) {
  // is pmode active?
  if (pmode) {
    digitalWrite(LED_PMODE, HIGH);
  } else {
    digitalWrite(LED_PMODE, LOW);
  }
  // is there an error?
  if (ISPError) {
    digitalWrite(LED_ERR, HIGH);
  } else {
    digitalWrite(LED_ERR, LOW);
  }

  // light the heartbeat LED
  heartbeat();
  if (SERIAL.available()) {
    avrisp();
  }
}

uint8_t getch() {
  while (!SERIAL.available());
  return SERIAL.read();
}
void fill(int n) {
  for (int x = 0; x < n; x++) {
    buff[x] = getch();
  }
}

#define PTIME 30
void pulse(int pin, int times) {
  do {
    digitalWrite(pin, HIGH);
    delay(PTIME);
    digitalWrite(pin, LOW);
    delay(PTIME);
  } while (times--);
}

void prog_lamp(int state) {
  if (PROG_FLICKER) {
    digitalWrite(LED_PMODE, state);
  }
}

uint8_t spi_transaction(uint8_t a, uint8_t b, uint8_t c, uint8_t d) {
  SPI.transfer(a);
  SPI.transfer(b);
  SPI.transfer(c);
  return SPI.transfer(d);
}

void empty_reply() {
  if (CRC_EOP == getch()) {
    SERIAL.print((char)STK_INSYNC);
    SERIAL.print((char)STK_OK);
  } else {
    ISPError++;
    SERIAL.print((char)STK_NOSYNC);
  }
}

void breply(uint8_t b) {
  if (CRC_EOP == getch()) {
    SERIAL.print((char)STK_INSYNC);
    SERIAL.print((char)b);
    SERIAL.print((char)STK_OK);
  } else {
    ISPError++;
    SERIAL.print((char)STK_NOSYNC);
  }
}

void get_version(uint8_t c) {
  switch (c) {
    case 0x80:
      breply(HWVER);
      break;
    case 0x81:
      breply(SWMAJ);
      break;
    case 0x82:
      breply(SWMIN);
      break;
    case 0x93:
      breply('S'); // serial programmer
      break;
    default:
      breply(0);
  }
}

void set_parameters() {
  // call this after reading parameter packet into buff[]
  param.devicecode = buff[0];
  param.revision   = buff[1];
  param.progtype   = buff[2];
  param.parmode    = buff[3];
  param.polling    = buff[4];
  param.selftimed  = buff[5];
  param.lockbytes  = buff[6];
  param.fusebytes  = buff[7];
  param.flashpoll  = buff[8];
  // ignore buff[9] (= buff[8])
  // following are 16 bits (big endian)
  param.eeprompoll = beget16(&buff[10]);
  param.pagesize   = beget16(&buff[12]);
  param.eepromsize = beget16(&buff[14]);

  // 32 bits flashsize (big endian)
  param.flashsize = buff[16] * 0x01000000
                    + buff[17] * 0x00010000
                    + buff[18] * 0x00000100
                    + buff[19];

  // AVR devices have active low reset, AT89Sx are active high
  rst_active_high = (param.devicecode >= 0xe0);
}

void start_pmode() {

  // Reset target before driving PIN_SCK or PIN_MOSI

  // SPI.begin() will configure SS as output, so SPI master mode is selected.
  // We have defined RESET as pin 10, which for many Arduinos is not the SS pin.
  // So we have to configure RESET as output here,
  // (reset_target() first sets the correct level)
  reset_target(true);
  pinMode(RESET, OUTPUT);
  SPI.begin();
  SPI.beginTransaction(SPISettings(SPI_CLOCK, MSBFIRST, SPI_MODE0));

  // See AVR datasheets, chapter "SERIAL_PRG Programming Algorithm":

  // Pulse RESET after PIN_SCK is low:
  digitalWrite(PIN_SCK, LOW);
  delay(20); // discharge PIN_SCK, value arbitrarily chosen
  reset_target(false);
  // Pulse must be minimum 2 target CPU clock cycles so 100 usec is ok for CPU
  // speeds above 20 KHz
  delayMicroseconds(100);
  reset_target(true);

  // Send the enable programming command:
  delay(50); // datasheet: must be > 20 msec
  spi_transaction(0xAC, 0x53, 0x00, 0x00);
  pmode = 1;
}

void end_pmode() {
  SPI.end();
  // We're about to take the target out of reset so configure SPI pins as input
  pinMode(PIN_MOSI, INPUT);
  pinMode(PIN_SCK, INPUT);
  reset_target(false);
  pinMode(RESET, INPUT);
  pmode = 0;
}

void universal() {
  uint8_t ch;

  fill(4);
  ch = spi_transaction(buff[0], buff[1], buff[2], buff[3]);
  breply(ch);
}

void flash(uint8_t hilo, unsigned int addr, uint8_t data) {
  spi_transaction(0x40 + 8 * hilo,
                  addr >> 8 & 0xFF,
                  addr & 0xFF,
                  data);
}
void commit(unsigned int addr) {
  if (PROG_FLICKER) {
    prog_lamp(LOW);
  }
  spi_transaction(0x4C, (addr >> 8) & 0xFF, addr & 0xFF, 0);
  if (PROG_FLICKER) {
    delay(PTIME);
    prog_lamp(HIGH);
  }
}

unsigned int current_page() {
  if (param.pagesize == 32) {
    return here & 0xFFFFFFF0;
  }
  if (param.pagesize == 64) {
    return here & 0xFFFFFFE0;
  }
  if (param.pagesize == 128) {
    return here & 0xFFFFFFC0;
  }
  if (param.pagesize == 256) {
    return here & 0xFFFFFF80;
  }
  return here;
}


void write_flash(int length) {
  fill(length);
  if (CRC_EOP == getch()) {
    SERIAL.print((char) STK_INSYNC);
    SERIAL.print((char) write_flash_pages(length));
  } else {
    ISPError++;
    SERIAL.print((char) STK_NOSYNC);
  }
}

uint8_t write_flash_pages(int length) {
  int x = 0;
  unsigned int page = current_page();
  while (x < length) {
    if (page != current_page()) {
      commit(page);
      page = current_page();
    }
    flash(LOW, here, buff[x++]);
    flash(HIGH, here, buff[x++]);
    here++;
  }

  commit(page);

  return STK_OK;
}

#define EECHUNK (32)
uint8_t write_eeprom(unsigned int length) {
  // here is a word address, get the byte address
  unsigned int start = here * 2;
  unsigned int remaining = length;
  if (length > param.eepromsize) {
    ISPError++;
    return STK_FAILED;
  }
  while (remaining > EECHUNK) {
    write_eeprom_chunk(start, EECHUNK);
    start += EECHUNK;
    remaining -= EECHUNK;
  }
  write_eeprom_chunk(start, remaining);
  return STK_OK;
}
// write (length) bytes, (start) is a byte address
uint8_t write_eeprom_chunk(unsigned int start, unsigned int length) {
  // this writes byte-by-byte, page writing may be faster (4 bytes at a time)
  fill(length);
  prog_lamp(LOW);
  for (unsigned int x = 0; x < length; x++) {
    unsigned int addr = start + x;
    spi_transaction(0xC0, (addr >> 8) & 0xFF, addr & 0xFF, buff[x]);
    delay(45);
  }
  prog_lamp(HIGH);
  return STK_OK;
}

void program_page() {
  char result = (char) STK_FAILED;
  unsigned int length = 256 * getch();
  length += getch();
  char memtype = getch();
  // flash memory @here, (length) bytes
  if (memtype == 'F') {
    write_flash(length);
    return;
  }
  if (memtype == 'E') {
    result = (char)write_eeprom(length);
    if (CRC_EOP == getch()) {
      SERIAL.print((char) STK_INSYNC);
      SERIAL.print(result);
    } else {
      ISPError++;
      SERIAL.print((char) STK_NOSYNC);
    }
    return;
  }
  SERIAL.print((char)STK_FAILED);
  return;
}

uint8_t flash_read(uint8_t hilo, unsigned int addr) {
  return spi_transaction(0x20 + hilo * 8,
                         (addr >> 8) & 0xFF,
                         addr & 0xFF,
                         0);
}

char flash_read_page(int length) {
  for (int x = 0; x < length; x += 2) {
    uint8_t low = flash_read(LOW, here);
    SERIAL.print((char) low);
    uint8_t high = flash_read(HIGH, here);
    SERIAL.print((char) high);
    here++;
  }
  return STK_OK;
}

char eeprom_read_page(int length) {
  // here again we have a word address
  int start = here * 2;
  for (int x = 0; x < length; x++) {
    int addr = start + x;
    uint8_t ee = spi_transaction(0xA0, (addr >> 8) & 0xFF, addr & 0xFF, 0xFF);
    SERIAL.print((char) ee);
  }
  return STK_OK;
}

void read_page() {
  char result = (char)STK_FAILED;
  int length = 256 * getch();
  length += getch();
  char memtype = getch();
  if (CRC_EOP != getch()) {
    ISPError++;
    SERIAL.print((char) STK_NOSYNC);
    return;
  }
  SERIAL.print((char) STK_INSYNC);
  if (memtype == 'F') {
    result = flash_read_page(length);
  }
  if (memtype == 'E') {
    result = eeprom_read_page(length);
  }
  SERIAL.print(result);
}

void read_signature() {
  if (CRC_EOP != getch()) {
    ISPError++;
    SERIAL.print((char) STK_NOSYNC);
    return;
  }
  SERIAL.print((char) STK_INSYNC);
  uint8_t high = spi_transaction(0x30, 0x00, 0x00, 0x00);
  SERIAL.print((char) high);
  uint8_t middle = spi_transaction(0x30, 0x00, 0x01, 0x00);
  SERIAL.print((char) middle);
  uint8_t low = spi_transaction(0x30, 0x00, 0x02, 0x00);
  SERIAL.print((char) low);
  SERIAL.print((char) STK_OK);
}
//////////////////////////////////////////
//////////////////////////////////////////


////////////////////////////////////
////////////////////////////////////
void avrisp() {
  uint8_t ch = getch();
  switch (ch) {
    case '0': // signon
      ISPError = 0;
      empty_reply();
      break;
    case '1':
      if (getch() == CRC_EOP) {
        SERIAL.print((char) STK_INSYNC);
        SERIAL.print("AVR ISP");
        SERIAL.print((char) STK_OK);
      } else {
        ISPError++;
        SERIAL.print((char) STK_NOSYNC);
      }
      break;
    case 'A':
      get_version(getch());
      break;
    case 'B':
      fill(20);
      set_parameters();
      empty_reply();
      break;
    case 'E': // extended parameters - ignore for now
      fill(5);
      empty_reply();
      break;
    case 'P':
      if (!pmode) {
        start_pmode();
      }
      empty_reply();
      break;
    case 'U': // set address (word)
      here = getch();
      here += 256 * getch();
      empty_reply();
      break;

    case 0x60: //STK_PROG_FLASH
      getch(); // low addr
      getch(); // high addr
      empty_reply();
      break;
    case 0x61: //STK_PROG_DATA
      getch(); // data
      empty_reply();
      break;

    case 0x64: //STK_PROG_PAGE
      program_page();
      break;

    case 0x74: //STK_READ_PAGE 't'
      read_page();
      break;

    case 'V': //0x56
      universal();
      break;
    case 'Q': //0x51
      ISPError = 0;
      end_pmode();
      empty_reply();
      break;

    case 0x75: //STK_READ_SIGN 'u'
      read_signature();
      break;

    // expecting a command, not CRC_EOP
    // this is how we can get back in sync
    case CRC_EOP:
      ISPError++;
      SERIAL.print((char) STK_NOSYNC);
      break;

    // anything else we will return STK_UNKNOWN
    default:
      ISPError++;
      if (CRC_EOP == getch()) {
        SERIAL.print((char)STK_UNKNOWN);
      } else {
        SERIAL.print((char)STK_NOSYNC);
      }
  }
}

Any help greatly appreciated

[pylon]

@bkellett

Mega Pin 51 --> MOSI of Target ICSP Header
Mega Pin 50 --> MISO of Target ICSP Header
Mega Pin 52 --> SCK of Target ICSP Header
Mega Pin 10 --> Reset of Target ICSP Header

GND connection is missing!

[bkellett]

Connect ground of my Mega to my Target? My target is running on a seperate DC battery pack that feeds it 12V

[jremington]

@bkellett

Connect ground of my Mega to my Target?

Yes, of course. GND = voltage reference and signal return path, as is required.

[bkellett]

Ok now that's done, connected GND of Mega to the GND ICSP pin of my target. When I still try burn bootloader:

avrdude: Yikes!  Invalid device signature.
         Double check connections and try again, or use -F to override
         this check.

Error while burning bootloader.

[sterretje]

Are your trying to program while the Wiz5500 is connected. As far as I know the Wiz5500 uses SPI and that might interfere with ICSP.

[bkellett]

My Wiz5500 would be connected yes, as it is on the same target board. The only I/O I have to this board is the ICSP header. I've attached a schematic below of my target board

Schematic_Nano+Wiznet R1 copy_2022-06-02 (3).pdf (161.4 KB)

[6v6gt]

What is the MCU: ATmega328 (as shown) or Atmega328P (as say in the Nano) ? This may be relevant to the invalid signature issue.
You appear to be trying to load a bootloader onto it but you have not broken out an FTDI header and there is no capacitor for the DTR pin of the FTDI (or similar) adaptor so it is not clear what the purpose of the bootloader would be.

[bkellett]

The package I can see on the PCB is ATMEGA328 U-TH (354730 2140PG6).

I'm just trying to upload my program to the board, via my Arduino Mega Board. From looking online, this method seemed to be the way so hence I was following it. I am not too familiar with FTDI. I do just have an ICSP header on board for I/O and nothing else.

[6v6gt]

Loading a program (sketch) over the ICSP header should work. Loading the bootloader initially will set the fuses so it is correct that you try it. The FTDI header is optional but at least TX and RX would be useful so you can use the serial monitor for debugging.
However, you still have the problem that the ATmega328 which you are using has a different device signature to ATmega328p. Some Arduino cores can handle that, for example miniCore GitHub - MCUdude/MiniCore: Arduino hardware package for ATmega8, ATmega48, ATmega88, ATmega168, ATmega328 and ATmega328PB but the official Arduino core does not. But before you proceed further, can you show a bit more of the error messages that you got in post #5 including the signature that it actually found (if any).

[bkellett]

Arduino: 1.8.15 (Windows 10), Board: "Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"

avrdude: Yikes! Invalid device signature.

     Double check connections and try again, or use -F to override

     this check.

Error while burning bootloader.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Does my target need to be connected for this? Also - I just realized perhaps the board I was trying is blown. I have multiple so its fine, it was supposed to be designed for 12V input but I now notice no LED's are lit. I will retry with a lower rated voltage supply

[6v6gt]

@bkellett

Does my target need to be connected for this?

Yes. The process you are following is attempting to load a program (in this case a bootloader) into the flash memory of the target ATmega328. When you select a board type in the IDE, this is naturally the ATmega328. If you select a Uno for example, which is close, and it gets further, you'll get a much more explicit error message saying what signature was found and what it expected. At that stage, you have then to load a core which can handle the ATmega328.

You said this in your first post:

@bkellett

I have set my programmer mode to "Arduino as ISP". My mega board just has the blink example loaded onto it at the moment.

I suppose that you have, in the meantime, loaded that ArduinoISP sketch onto it

[pylon]

@bkellett

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

Did you read that part of the output? Did you follow the instruction there?