CC Load

Programmable DC Load

Flexible programmable DC constant current/power load using Arduin Nano and a custom PCB.

Following some ideas from this YouTube playlist from Scullcom Hobby Electronics.

PCB design and schematic

Finished device in enclosure

Programming the ATmega328P

Setting the fuses

If you just want the same ones as used in a standard Arduino, you can find them in the boards.txt file:

uno.bootloader.low_fuses=0xff
uno.bootloader.high_fuses=0xde
uno.bootloader.extended_fuses=0x05

We will be using another Arduino as ISP, so we should first program it with given example code, then we can use avrdude option 'avrisp', and use the port number of that device. We can read the fuses, and check if conncections are ok with:

.\utils\avrdude-v8.0\avrdude.exe -c avrisp -p m328p -P com23 -b 19200 -U lfuse:r:-:i -U hfuse:r:-:i -U efuse:r:-:i -v

So for these default settings we would use the following command:

.\utils\avrdude-v8.0\avrdude.exe -c avrisp -p m328p -P com23 -b 19200 -U lfuse:w:0xFF:m -U hfuse:w:0xDE:m -U efuse:w:0x05:m -v

Where:

  -c <programmer>                          Specify programmer type.
  -p <partno>                              Required. Specify AVR device.
  -P <port>                                Specify connection port.
  -b <baudrate>                            Override RS-232 baud rate.
  -U <memtype>:r|w|v:<filename>[:format]   Memory operation specification.
  -v                                       Verbose output. -v -v for more.

More options info can be found here.

Burning the bootloader

To burn the bootloader, we will also be using Arduino as ISP, and in Arduino software just select burn bootloader after we select the board as Arduino Uno.

Flashing the program

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