Electronic – Using a microcontroller to program another microcontroller (on a wireless board)

microcontrollerprogrammingwireless

I am working on a project in which I want to include the functionality of reprogramming the main microcontroller via wireless transmission.

First, I have figured there needs to be a dedicated microcontroller programmed to facilitate this function, but how exactly would it need to be implemented?

Assuming the code is already compiled before transmission, would the code need to be stored in any specific way prior to being read and used to program the main controller?

Also, what exactly is the process required to facilitate the actual programming of the controller?

Best Answer

Some controllers can write to their own program flash under software control; others cannot. If you need to use a secondary processor to program the primary one, it's really not much different from any other task that requires willing certain pins in certain sequences with certain timing constraints. The one biggest thing to look for is that some parts can be programmed in a variety of ways, some of which may be much faster than others. If the part to be programmed can write to parts of its own flash under software control but can't do everything and thus requires the use of a secondary processor, it may sometimes be fastest to have the secondary processor program the primary one with just enough of a boot loader to receive its code via some other means (such as a UART) than to use the in-circuit programming mode for everything.

Related Solutions

How to get data from one micro controller to another using UART

I dont understand your confusion. You want to communicate between the two controllers with UART, then ofcourse both of them need UART capabilities and code for this. Your computer has drivers and software for dealing with this, so your microcontroller also needs a driver for it.

Your ATmega32 need UART TX functionality, while AT90USB1287 need UART RX functionality. Having already written both TX and RX for your ATmega32, writing the UART RX routine for AT90 should be a breese. You could add a bitvalue of some kind, identifying that the UART RX on AT90 is coming from your ATmega32, and directly pass it through to USB.

EDIT: Code from AVRFreaks that is written for at90usb1287

#include <avr/io.h> 
#include <util/delay.h> 

#define RXC      (RXC1) 
#define TXC      (RXC1) 
#define UCSRC    (UCSR1C) 
#define UCSRB    (UCSR1B) 
#define UCSRA    (UCSR1A) 
#define UDR      (UDR1) 
#define UBRRL    (UBRR1L) 
#define UBRRH    (UBRR1H) 
#define UBRR     (UBRR1) 
#define UDRE     (UDRE1) 
#define RXCIE    (RXCIE1) 
#define TXEN     (TXEN1) 
#define RXEN     (RXEN1) 
#define UCSZ0    (UCSZ10) 
#define UCSZ1    (UCSZ11) 
#define UMSEL0   (UMSEL10) 
#define UMSEL1   (UMSEL11) 

#define FRAMING_ERROR (1<<FE1) 
#define PARITY_ERROR (1<<UPE1) 
#define DATA_OVERRUN (1<<DOR1) 
#define DATA_REGISTER_EMPTY (1<<UDRE1) 
#define RX_COMPLETE (1<<RXC1) 

#define FOSC 16000000 

typedef unsigned char       Uchar; 
typedef unsigned long int   Uint32; 

#define Wait_USART_Ready() while (!(UCSR1A & (1<<UDRE1))) 

#define lowByte(w) ((uint8_t) ((w) & 0xff)) 
#define highByte(w) ((uint8_t) ((w) >> 8)) 

int main(void) 
{ 
/* Disable clock division */ 
clock_prescale_set(clock_div_1); 
   UBRRH = (Uchar)((((Uint32)FOSC)/((Uint32)USART_BAUDRATE*16)-1)>>8); 
   UBRRL = (Uchar)(((Uint32)FOSC)/((Uint32)USART_BAUDRATE*16)-1) & 0x0ff; 

   UCSRB |= (1 << RXEN) | (1 << TXEN); 
   UCSRC |= (1 << UCSZ1) | (1 << UCSZ0); 

   char ReceivedByte; 
   for (;;) // Loop forever 
   { 
      while ((UCSRA & (1 << RXC)) == 0) {}; // Do nothing until data have been received and is ready to be read from UDR 
      ReceivedByte = UDR; // Fetch the received byte value into the variable "ByteReceived" 

      while ((UCSRA & (1 << UDRE)) == 0) {}; // Do nothing until UDR is ready for more data to be written to it 
      UDR = ReceivedByte; // Echo back the received byte back to the computer 
   } 
}

Electronic – arduino – How to graduate from Arduino to using a microcontroller directly

Welcome to the wonderful world of Atmel. Let me offer you some answers to your questions based on my hobby and professional experience.

Do not bother with anything BUT in-circuit programming. Unless you are a perfect coder, removing a chip every time you want to program it is a nightmare. I recommend the AVRISPmkII as an entry level programming tool. The disadvantage is there is no hardware debug supported. An alternative is the dragon but I have no experience with that. I can say that the JTAGICEmk3 is a nice capable debug tool.

Atmel studio is good for programming. It is actually my favorite embedded development environment. You can use CLI tools such as AVRDUDE and AVR-GCC but the IDE takes care of that for you.

IN SUMMARY:

Buy an AVRISP for just programming (easier, plug&play) or a DRAGON (I can not offer advice).

On your board, bring out the ICSP pins to a 6-pin dual row 0.100" header -- the connections are described in this datasheet.

Reset switches are not needed.

Best Answer

Related Solutions

How to get data from one micro controller to another using UART

Electronic – arduino – How to graduate from Arduino to using a microcontroller directly

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