I read where someone put the bootloader on their SMD Atmega328P by just manually pressing/holding it on pads while the bootloader loaded. I made this little board to do this, but before I add it to my next BatchPCB order, I had 2 questions.
I designed it where I could just plug it into pins 8 thru 13 on my UNO. Will pins 8 and 9 supply enough current to do this task? 8 will be the ground, 9 will be +5 volts.
Also, if the connection fails during the bootloading process, does that 'brick' the chip?
thanks,
ps. All the components (caps, crystal, and a test LED-to verify success via the blink sketch) will be soldered to the board. Only the Atmega328P-AU will be left blank, to manually hold the chip on and bootload it.
• Get rid of the capacitor on AREF. When burning a bootloader it serves no useful purpose.
• Follow pito's advice. Get some decoupling capacitors on those power lines.
• Drop the crystal + capacitors. I would use a clock signal from the programmer (are you using ArduinoISP?) instead. Less soldering. Fewer things that can go wrong. Easier to fix if something is wrong.
• Have holes drilled around the target's corners so I could potentially put in "pillars" to keep the target aligned.
• Include a sketch with the bootloader that blinks the LED on PD3 as confirmation that bootloading worked.
Will pins 8 and 9 supply enough current to do this task? 8 will be the ground, 9 will be +5 volts.
There have been various problems reported on the forum when VCC / GND pins were left unconnected. I suggest making a valiant effort to get them all powered.
SouthernAtHeart:
I designed it where I could just plug it into pins 8 thru 13 on my UNO. Will pins 8 and 9 supply enough current to do this task? 8 will be the ground, 9 will be +5 volts.
I think he means he wants to power the jig via the Uno (ArduinoISP) pins 8 and 9. Probably not recommended.
I guess that would make it very convenient since it’s small and compact to just plug the board into the Uno headers with just the 6-pins. Yes, that is clever.
Edited my layout a bit, and will see how it works. Yes the diode is for testing purposes, so I know it's flashed before soldering it on an important board. I first designed it to sit inside the perimeter of the UNO, but then changed it so it sets on pins 8 thru 13, on the outside, with the chip on the very outside of the little 1" square board. I have a tiny spring clamp, about like a clothes pin, I can clamp the chip on with that, visually inspect it for squareness, and flash away.
I'll let you know how it works in about a month.
I saw that for the first time on Jeenodes.. DIY PCB's, staggered pins and I thought it for a special connector till I fitted a 6 pin female to the holes and it didn't fall out..
it comes as a 'kit' without the ATmega328P-AU chip soldered on.. so you can put blanks in there..
(similar to your solution)
the problem I was (am) having is that the crystal on this board is 16MHz.. and the end board I am trying to put the chip in is a 8MHz board... so the hobby king cable would fix that!
question:
I see the hobby king cable mention needing to beused with an AVR programmer..etc..etc..
would the Arduino/IDE suffice in this instance as well? or does one need a special DEDICATED programing hardware?
(I have only ever used the Arduino/IDE for flashing bootloaders)