Hi,
I'm working on the OpenTRV project (I expect I can't post links initially and so I won't even try, but you can find it with your favourite search engine if you wish) for saving energy in heating systems with a smart retrofit Thermostatic Radiator Valve and some stuff to call for heat from a boiler centrally.
I already have a PICAXE prototype up and running at my house across multiple nodes each controlling wireless valves via RFM22/RFM23, etc.
I want to build a parallel ATmega/Arduino stack which I expect to be able to do more sophisticated things, and more power-efficiently.
In some configurations our hardware will be powered by a couple of AA rechargeables so operation down to around 2V is needed, but operation at 3.3V (or 5V) may also happen, eg at mains-powered nodes.
I have so far succeeded in using my UNO as ISP to get a (8MHzRC/8, see below) bootloader into a couple of blank ATmega328P chips (so far as I can tell), but moving on to program them a TTL-232R-3V3 has me foxed so far.
I am running IDE 1.0.3 on a Mac.
I have added this to the end of the boards.txt file:
atmega328bb2AA.name=ATmega328 on a breadboard (8 MHz internal clock / 8), 2xAA supply 1.8V BOD
atmega328bb2AA.upload.protocol=stk500
atmega328bb2AA.upload.maximum_size=30720
atmega328bb2AA.upload.speed=57600
atmega328bb2AA.bootloader.low_fuses=0x62
atmega328bb2AA.bootloader.high_fuses=0xDA
atmega328bb2AA.bootloader.extended_fuses=0x06
atmega328bb2AA.bootloader.path=arduino:atmega
atmega328bb2AA.bootloader.file=ATmegaBOOT_168_atmega328_pro_8MHz.hex
atmega328bb2AA.bootloader.unlock_bits=0x3F
atmega328bb2AA.bootloader.lock_bits=0x0F
atmega328bb2AA.build.mcu=atmega328p
atmega328bb2AA.build.f_cpu=1000000L
atmega328bb2AA.build.core=arduino
atmega328bb2AA.build.variant=standard
Note in particular the fuses (so the CPU clock is 1MHz, and BOD is set at 1.8V) and the f_cpu (set to 1MHz correctly) I hope.
Attempting to load the blink sketch spits out, after a pause:
avrdude: stk500_recv(): programmer is not responding
My best guess was that I probably also had to reduce "upload.speed" to 7200, but no luck so far.
I have automatic reset apparently working (reset tied high with 10K, via 100nF to RTS, so a LED on digital pin 13 (PB5) blinks when the IDE opens the connection and slowly thereafter).
I'm pretty familiar with electronics and computing, but have no AVR-specific test gear. I have a couple of these 328Ps, an UNO and a Leonardo.
Any other clues?
Rgds
Damon