SparkFun Forums

[tfinks]

Let's say I design and build a derivative of an Arduino board. Is there anything Arduino-specific that needs to be done to the off-the-shelf processor to make it work with the Arduino ecosystem?

[Stuart.W]

you'll need to setup the proper microcode in the the ATmega chips, the preprogramed chips are available on the internet. But, you can buy an Arduino much cheaper then you can build one...., even here in Arkansas...

[jremington]

Bootloader, unless you use an ISP programmer. http://www.gammon.com.au/breadboard

[Valen]

Most boards that have a usb-to-serial chip also can do auto-reset of the chip by pulsing the DTR pin (or RTS on really old boards) of the serial port. Otherwise a manual reset is necessary when programming.

[Valen]

[can't edit anymore] ... and it is hard to get the timing right.

[tfinks]

My thanks for the helpful replies.

I've ordered a Pocket AVR programmer, and I'll add a header and processor reset to the target hardware.

[jremington]

If you intend to use the Arduino DTR automatic reset method for uploading, the board should have a 0.1 uF capacitor between /RESET (with 10K pullup) and DTR.

[Belarm]

Hey,

I have made my own board with Atmega32U4 and 2 acceleromters. I have put an Arduino bootloader of Sparkfun Pro Micro (3.3V,8MHz) on it. But the problem is that I have used pins PF0 and PF1 of Atmega as chip select pins, but in Sparkfun Pro Micro they are not used. So how can I define them in Arduino ? int CS =A4 doesn't works. Is there other way to do it like "int CS = pin.PF0" or something like that? Thanks.