ATMEGA328AU bootloader and programming sketches

I needed to update how to boot-load and program ATMEGA328AU chips.

Attached is a brief rundown on how-to.

I hope you find it useful.

PDF

From breadboard to protoshield

Tests on both the light and sound circuits on breadboard were promising. They tests did show a great deal of false triggering and I believe this was due to the bad connection nature of breadboards.

I took both circuits and layed them out on protoboard. This allows direct connection to the Arduino.

Tests so far are very promising.

soundTrigger circuit with microphone in the background

stormTrigger V3 layed out and working well

soundTrigger rising

Playing with an electret microphone and a simple circuit.
A Mega328 samples the noise generated by the circuit and triggers a camera on the output via an opto-isolator.

Schematic in Eagle

Bread boarded Prototype

Measuring I/O performance

Performance looks promising. Measuring a triggering delay of 35uS (microseconds).
Arduino sketch to follow...

Program TQFP32 MEGA328P (Arduino)

A quick look on the web reveals a lack of ways to get a bootloader onto an MEGA328P AU in TQFP32 SMD package.

Atmel have a board available for their STK600 development kit (Atmel.com). With some modification the board can fit to an Arduino on the standard headers, and have bootloaders burned easily.

A good alternative is available on ebay (here). However you will need to add a PCB to adapt to Arduino headers.

Oscillator circuit (crystal, capacitors and resistor) connected to xtal1, xtal2 and GND.

Birdsnest of interconnecting cables from the Arduino headers.

Closeup of MEGA328P in place for programming

Remove the MEGA328P from the Arduino

Mount the AVR board to the Arduino

Hook up the set via USB to your PC then use the following to program the TQFP32 MEGA328P

That gets the bootloader onto the chip.

You will need to include a header on your PCB to access TX, RX, RESET, 5V and GND to program the MEGA328P from the Arduino environment, using an Uno to pass-through the signals, or a standard ICSP header for programming via Atmel Studio and an AVRISPII.

Version 2 arrives...

The V2 PCB arrived from Silver Circuits last week. I am quite satisfied with performance after preliminary tests using Canon 5D MK3, 7D and Nikon D3100.

This circuit is a much more efficient board layout and dimensions come in at 8cm x 6cm. The LCD is an 8x2 type which is sufficient for display and settings.

Version 2 PCB with V0.96a software

This photo was taken using a DSLR with a radio trigger. Settings were 1/200 @ f2.8 with the flash set to 1/64th power, bounced at the ceiling. You can see the green LED within the rotary encoder is illuminated showing a flash has been detected.

I have added a second 3.5mm input to the PCB (center jack socket on the left) for expansion purposes I will go into later.

Contact me if you have any questions: phase1consult@gmail.com

The stormTrigger

Back to September 2011.

A quality camera triggering device is expensive.

The need for a lightning trigger was highlighted to me while staying in Hat Yai for a few days. Setting up a tripod on a balcony then setting the camera to long exposure mode, and continuously pressing the shutter, hoping to capture a lightning strike proved to be very hit & miss.

I have been playing with Atmega microcontrollers for a few months now, developing my understanding of programming and interfacing with sensors.

I set about deciding upon the specifications.