Internal clock on a breadboard Arduino

Community General Discussion
1

Hello, y'all,

I am currently building a wristwatch based on an Atmega328. I wouldn't call it an Arduino, clone or variant thereof, because this board is pretty much a socket and the I/O bus. Most people would call it a minimalist arduino (http://arduino.cc/en/Tutorial/ArduinoToBreadboard), but I call it pain.
My design is simple: an Atmega328 running on the internal clock, sending every minute a string of bits to a 74HC595. The 595 drives a 7-segment display and another 595... This interface I have flawlessly put together (sort of) with an Uno. But an Uno is too large for something to go on my arm, so I plan to migrate the Atmega to a new board (prototyping style) with a dedicated area for the 595's.
So that's my plan. But the Atmega currently runs the Uno bootloader as an Uno CPU should. This of course implies that it be clocked externally with the 16MHz crystal. I cannot migrate the crystal to the board, nor do I even have one. Therefore I want to set the CKSEL flags for internal clocking (I know the accuracy of these clocks is dreadful for timekeeping). This I plan to do by burning the bootloader for an "Atmega328 on a breadboard (8MHz internal clock)" onto it by using my handy second Uno with the ISP program.
Finally I am at the problem (woo). The Arduino Uno refuses to work with the Atmega328. Like, totally.

Details of the problem are...varied, actually. I have received the errors:

  1. Yikes! Device signature wrong or something. Check your wiring or somehow apply -F to skip this check.
  2. avrsomethingstk_500derp(): not in sync: expect 0xblah resp=0x00
  3. " resp=0x1C
  4. " resp=0x14

Looking at the article mentioned above, I found that "these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168)."
The article, almost spitefully, singled out the Uno as incompatible. Table-flips my setup out the window.
Reading other articles (understatement), I found that connecting a 10uF capacitor across the reset and ground pins will get the Uno to work. You can tell it didn't.

I have two Arduino Pro Minis, an Uno R3, and an Uno R3 SMD Edition. The Atmega328 comes from the Uno R3, the remaining board thereof I can use to program my Pro Mini boards. The CPU in the watch will be removable when I need to use the Uno R3.

2

FSA-00:
I am currently building a wristwatch based on an Atmega328.

Do you seriously mean a wristwatch? For keeping time? But then you go on to say you propose to use the internal clock of the 328, which is absolutely useless for keeping time! Care to explain this conflict?

FSA-00:
Most people would call it a minimalist Arduino (http://arduino.cc/en/Tutorial/ArduinoToBreadboard), but I call it pain.

And pain it certainly sounds like - using a tutorial from the site here. I suggest using Nick Gammon's tutorial instead.

FSA-00:
So that's my plan. But the Atmega currently runs the Uno bootloader as an Uno CPU should. This of course implies that it be clocked externally with the 16MHz crystal. I cannot migrate the crystal to the board, nor do I even have one. Therefore I want to set the CKSEL flags for internal clocking (I know the accuracy of these clocks is dreadful for timekeeping).

So why do you want to use the internal clock?

And why do you want a bootloader at all if it is not going to be connected to a serial port?

FSA-00:
This I plan to do by burning the bootloader for an "Atmega328 on a breadboard (8MHz internal clock)" onto it by using my handy second Uno with the ISP program. Finally I am at the problem (woo). The Arduino Uno refuses to work with the Atmega328. Like, totally.

Do you have a clock on the Atmega328?

FSA-00:
Looking at the article mentioned above, I found that "these techniques only work with the Arduino Duemilanove w/ an ATmega328, not the Arduino Uno (or older Arduino boards w/ an ATmega168)." The article, almost spitefully, singled out the Uno as incompatible.

And it is in fact, total garbage, a relic of Arduino prehistory. The UNO R3 will work perfectly.

FSA-00:
Reading other articles (understatement), I found that connecting a 10uF capacitor across the reset and ground pins will get the Uno to work. You can tell it didn't.

Read Nick Gammon's tutorials.

FSA-00:
I have two Arduino Pro Minis, an Uno R3, and an Uno R3 SMD Edition. The Atmega328 comes from the Uno R3, the remaining board thereof I can use to program my Pro Mini boards. The CPU in the watch will be removable when I need to use the Uno R3.

You will need a clock on the breadboard chip in order to access it with the ISP in order to change the clock fuses. You actually do not need a crystal, any recent UNO or the Pro Minis - any of them can be used to provide the clock. Just read Nick's articles (and forget Arduino Tutorials here - so many blunders and omissions).

3

Thanks for replying, and I now notice I failed to mention that I did in fact read Nick Gammon's article. Or...the one with the SD card? But now I have found in the Atmel website that other crystal values can be used, some of which are accessible. That I will attempt to use. In the time since my initial post I have found a new method which had not yet worked. Does anyone here have information about removing the CPU from the Uno and connecting its Sck, Mosi, Miso and Reset pins to those of the Atmega328, then burning a Lilypad bootloader? Would it be possible to just burn the 8MHz bootloader onto the Uno with the Atmega installed, lkke does the existing clock have to match the one being burned?ll

4

Paul__B, I can just see the look of abhorrence on your face as you read my initial post. So I will attempt to work with a 4MHz crystal I may or may not have desoldered from a junk PCB. But it is 4MHz, which is 3x slower than the 16MHz the ISP is expecting. Long exhale of air directed at my bangs. Don't worry about timing issues, and this is kinda like a cover story for my FS-PDBMATC-328-00, also called the F-duino. It was formed by the fsct that my existing watch beeps on the hour, which gets super annoying after an hour. Motives, you know. I'm not the kind of person who takes stuff seriously.ur.