Well the Subject says it all! I have made a standalone circuit using a xtal, atmage328pu, a nokia 5110 display, some buttons and some resistors/capasitators. So far doing the ethcing of the pcb in my kitchen.
Now I want to program it using a usb cable and move it all to smd. What chip shuld I use to do the translation between usb and atmega328pu? Or could I use some other atmega thats is compatible with Arduino and got a usb input/output?
Please help a old dog learn new tricks!
This being a timer, I'll might add a rtc chip if I can't make the internal timer accurate enogh (3 sec drift in 2.5 mins is NOT good enough)
ow I want to program it using a usb cable and move it all to smd. What chip shuld I use to do the translation between usb and atmega328pu? Or could I use some other atmega thats is compatible with Arduino and got a usb input/output?
Honestly, you have a few choices:
You can leave the FTDI (usb-serial) interface external like the Pro Mini.
You can integrate the Usb-Serial like the Nano.
You can virtualize the USB functionality like the Pro Micro.
This being a timer, I'll might add a rtc chip if I can't make the internal timer accurate enogh (3 sec drift in 2.5 mins is NOT good enough)
Do you really need full-time USB support? If not, then there is no reason to have a separate chip eating up precious battery supplied milliamps! Most of my non-attached to PC projects are built around the 328P based Pro Mini.
For projects that are battery powered and need occasional use of USB, I will typically use the Pro Micro based on the 32U4. The bootloader is essentially LUFA... can be HID or Com to the PC.
Rarely do I use the Nano, because of the extra current drain. I can, of course, cut the trace and install a jumper, but that is simply too much effort.
So far doing the ethcing of the pcb in my kitchen.
When 1st married, I was into model rockets in a big way (the world was different then, too.) My wife caught me making sugar rocket fuel in her kitchen and thought I was making candy since I was using her candy thermometer. When she learned it was rocket fuel, so invoked a vocabulary that suggests she was a reincarnated sailor. That was 41 years ago and I have not built a rocket since that faithful day....
Just saying, the kitchen sink may be contested territory unless you are living alone.
Ok,, if the 328 has got a arduino bootloader get a ftdi and just connect the serial pins and ground.
Bad thing with this is that you cannot use the pins for anything else.
if you want to do it good, get a icsp programmer and break out the spi pins and reset.
I have been using the ICSP so far, but now i want to step it up a bit to not having to use a programmer, but just a microusb cable. Updating the units on the go would be easier, and more fun to put more things into the pcb. This is a project I want to make a few units of, so I want it to be simple to use and simple to update, if it's simple to make that is not a drawback.
I got bootloaders on all my chips, but when I take the step to smd I need a way to burn the bootloader too.
I need to examine the possible ways to integrate the usb. I'm not sure what the different ways to interface with the usb? Full integration or serial or....
The project is a timer to be worn on my arm while shooting handguns, so it will be battery powered. The current drain is a problem, I want it to use less power to get more battery life from it.
I'm wondering about swap the atmega328pu through the hole chip with a AT90USB646 smd. The AT90USB646 does have native usb and a buildt in rtc. It's a bit overkill to use it, but one chip that got it all in one. Got to order some samples. Not having desided anything yet....
The kitchen is a womans domain, but what she doesn't know wont kill me! But rocketfuel, no thats not me. I'm reloading bullets on our dining table.
PunyViking:
Is it possible to do full programming via the V-USB concept? Both uploading sketches and burning bootloaders?
It's a geniuos consept if it all works!
Yes,
The USnoobie does it... requires one additional push-button in the current incarnation! I built out one over the Christmas holidays just for play - works as described on XP, Vista. Have no experience with Win7 or Win8 in the lab... unfortunately, it is everywhere else in the house to my dismay.
That looks like a good solution CrossRoads if I only har room for it. But that's way to big for my project. I hope to make all my electronics on a pbc the same size as the breakout board on the nokia 5110 display pluss a few miliimeters for some buttons.
The V-USB concept looks like a way to do it, or using the atmega32u2 chip. that chip can be programmed using the arduino ide. I still would like a chip with usb input and a rtc circuit in the chip.
