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mAVRISP

Table of Contents

    An mbed can be used for In-System Programming [ISP] of AVR microcontrollers over a simple three-wire SPI interface.

    The current version uses the simple AVR910 protocol to flash the Atmel chip.

    Example

    This example will run through programming an ATMega328P with the mAVRISP program.

    Hello World!

    Import program
    mAVRISP - main.cpp

    00001 /**
00002  * Program an AVR with an mbed.
00003  */
00004 
00005 #include "AVR910.h"
00006 
00007 LocalFileSystem local("local");
00008 Serial pc(USBTX, USBRX);
00009 AVR910 mAVRISP(p5, p6, p7, p8); //mosi, miso, sclk, nreset.
00010 
00011 int main() {
00012 
00013     int success  = -1;
00014     int response =  0;
00015 
00016     //Read the vendor code [0x1E == Atmel].
00017     response = mAVRISP.readVendorCode();
00018 
00019     if (response == ATMEL_VENDOR_CODE) {
00020         pc.printf("Microcontroller is an Atmel [0x%02x]\n", response);
00021     } else if (response == DEVICE_LOCKED) {
00022         pc.printf("Device is locked\n");
00023         return -1;
00024     } else {
00025         pc.printf("Microcontroller is not an Atmel\n");
00026         return -1;
00027     }
00028 
00029     //Read part family and flash size - see datasheet for code meaning.
00030     response = mAVRISP.readPartFamilyAndFlashSize();
00031 
00032     if (response == 0xFF) {
00033         pc.printf("Device code erased or target missing\n");
00034     } else if (response == 0x01) {
00035         pc.printf("Device locked\n");
00036         return -1;
00037     } else {
00038         pc.printf("Part family and flash size code is: 0x%02x\n", response);
00039     }
00040 
00041     //Read part number.
00042     response = mAVRISP.readPartNumber();
00043 
00044     if (response == 0xFF) {
00045         pc.printf("Device code erased or target missing\n");
00046     } else if (response == 0x02) {
00047         pc.printf("Device locked\n");
00048         return -1;
00049     } else {
00050         pc.printf("Part number code is: 0x%02x\n", response);
00051     }
00052 
00053     //Open binary file to write to AVR.
00054     FILE *fp = fopen(PATH_TO_BINARY, "rb");
00055 
00056     if (fp == NULL) {
00057         pc.printf("Failed to open binary. Please check the file path\n");
00058         return -1;
00059     } else {
00060         //Program it!
00061         pc.printf("Binary file opened successfully\n");
00062         success = mAVRISP.program(fp,
00063                                   ATMEGA328P_PAGESIZE,
00064                                   ATMEGA328P_NUM_PAGES);
00065         fclose(fp);
00066     }
00067 
00068     if (success < 0) {
00069         printf("Programming failed.\n");
00070     } else {
00071         printf("Programming was successful!\n");
00072     }
00073 
00074 }

    Wiring

    Atmel Pinmbed Pin
    MOSIp5
    MISOp6
    SCKp7
    nRESETp8
    VCCVout
    AVCCVout
    AREFVout
    GNDGND

    API

    Import program
    mAVRISP - AVR910 Class Reference

    Public Member Functions

    AVR910 (PinName mosi, PinName miso, PinName sclk, PinName nReset)
    Constructor.
    int program (FILE *binary, int pageSize, int numPages=1)
    Program the AVR microcontroller connected to the mbed.
    void setFrequency (int frequency)
    Set the frequency of the SPI communication.
    int readVendorCode (void)
    Read the vendor code of the device.
    int readPartFamilyAndFlashSize (void)
    Read the part family and flash size of the device.
    int readPartNumber (void)
    Read the part number.

    TODO

    References

    All wikipages