Attiny 44 in boot loop

I made my own board using Attiny 44A. It is simple board, made to drive couple of mosfets. Currently there are only MCU and power installed. The problem is that it seems to be stuck in a boot-loop even when the most simple blink-led application is used. Reboot happens in about 100ms interval.

I use AD0 and AD1 to measure input voltages. PB0 and PB1 are used to drive mosfets (currently only 10k resistors). Power output should be solid with 5V regulator and two 4.7uF multilayer ceramic capacitors (one after regulator and other in the near of MCU). Measured power fluctuation is less than 50mV (oscilloscope).

ICSP pins are connected to 6-pin header and I have successfully used Arduino atmega 2560 board as a ICSP programmer. Other pins are left unconnected, and I configure them as outputs (I have also tried not to do that). I have also tried to putk 10k (5V) pullup-resistor to reset-terminal.

Does anyone have similar problems or any idea what is causing this. All my sketches work well when flashed into mega 2560.

Do you have the 0.1uF ceramic cap between vcc and gnd right next to the chip? This is required for stable operation (as it is on nearly every digital ic)

Does blink work?

Yes. I have 0.1uF as well as 4.7uF. Right between power pins 1 and 14. I have 4.7uF because I can expect relatively high peak currents when driving mosfets.

Blink does not work properly. It will turn the output on, but reboot happens right after it, before delay has expired. Instead of 1s pulse, I see about 50ms pulse and then another after reboot.

I'm quite experienced designer, but haven't done much in past ten years. This is my first project with Attiny.

Using internal clock ?

Is it burnt for internal clock ?

(clutching at straws here :slight_smile: )

Yours,
TonyWilk

Yes. I'm using 8MHz internal clock. Device is as it was shipped meaning I haven't done any high voltage programming. I have been lazy and haven't read all the manuals and I assume that it should work with default settings. If it does not, it can be good reason for the failure. However, it obviously executes init-code and some instructions from loop(), so I'm afraid the problem is not that simple.

I have double checked the circuitry ad haven't found anything suspicious. In the matter of fact, power is more stable than I stated before. It was measured when connected into USB through AT Mega. When I use battery power, maximum peaks in MCU-power are about 5mV.

Tero:
I assume that it should work with default settings

Might be worth looking into the Watchdog...

Yours,
TonyWilk

Have you done "burn bootloader"? You need to do that on a new chip to set the clock speed.

I did 'burn bootloader'. I also tried disabling watchdog. Neither had any influence on the problem.

I'm starting to wonder if It's possible that my MCU is damaged. I soldered it with proper grounding, so it is hard to believe.

Thanks for DrAzzy for his post and advertisement. I was able to solve my problem. It was caused by malfunctioning core. Previously I used 'Attiny bu David A. Mellis 1.0.2'. For some reason that did not work with my board.

I installed Attiny Core from http://drazzy.com/package_drazzy.com_index.json and my board started to work immediately. Even my more complex final code works properly.

Now I got warnings like 'board xxx doesn't define 'Build board' preference', but those are much better than sketches which doesn't work at all.

Tero:
Thanks for DrAzzy for his post and advertisement. I was able to solve my problem. It was caused by malfunctioning core. Previously I used ‘Attiny bu David A. Mellis 1.0.2’. For some reason that did not work with my board.

I installed Attiny Core from http://drazzy.com/package_drazzy.com_index.json and my board started to work immediately. Even my more complex final code works properly.

Now I got warnings like ‘board xxx doesn’t define ‘Build board’ preference’, but those are much better than sketches which doesn’t work at all.

Can you get me the exact text of those error messages? Also what version of the IDE? I do not recall seeing those messages last time I was using my core, hence my concern.

I’m too lazy to write messages (since copy does not work), so you can see them from attached image.

My Arduino Ide version is 1.8.1.

Tero:
I'm too lazy to write messages (since copy does not work), so you can see them from attached image.

My Arduino Ide version is 1.8.1.

Those are coming from a different ATTiny core you have installed, not mine.

Okay. Then my configuration files are somehow messed up. I have board 'Attiny 24/44/84' and chip 'Attiny 44' selected.

Currently I have only 'Arduino AVR Boards' and you core files installed from boards manager. I have tried another ones but removed them. Maybe something have left behind.

I will reinstall my Arduino ide when I have time. Thank's for you for you help.