Simply. I have a component tester that I fried the mcu. A supposedly discharged capacitor wasn't so.
I really don't want to throw the thing away. But I do have SMD skills and the equipment.
The 32 pin QFP is marked as in the subject.
Atmel Mega328P U-TH.
Apparently a counterfeit chip. At any rate pretty impossible to locate in the USA.
It is clocked with an 8 MHz crystal.
I have found the firmware which includes the bootloader.
Could anyone please suggest a replacement IC?
I have searced suppliers and can get the Atmega328P. But with variants. And the clock speed appears to be 20 MHZ. Although I'm led to believe that is the internal speed and an external xtal overrides that.
My intention is to flash a new chip using a genuine Uno with the programmer in the IDE.
I'd really appreciate any help that you folks could offer.
It's been awhile since I logged in. Lost my credentials. So made a new user name.
I would buy that Atmega328p with the same physical package format and use that.
You can clock them all with external crystal or with the internal oscillator.
I don't quite follow you. The TQFP32 is the same as the one that is in the tester. I intend on removing it and replacing the defective chip in the tester. There are header pads in the tester and I would need to solder pins on them. The documentation for pinout is pretty vague so I would need to trace back to the chip to do that. There is a warning to desolder the TFT display ribbon cable also.
So. Besides the expense for a single use TQFP chip fixure. $5 USD at my door for a complete mini seemed like a good choice.
All of the documentation tells me I should be able to wipe the mini completely.
The reply from the youtube video linked below tells me this:
"Yes the bootloader is included. A totally blank chip is all you need (and a programmer of course)".
So. With dude I selected Force and Erase EEPROM before hitting Program.
With the correct .hex Program and .eep EEPROM file selected. I got no errors after the process.
I would have chosen to blank the chip. After overcoming fuse settings that locked the program area, etc.
As I mentioned. Blanking, zero filling eeproms like you see for pc bios and such is straight forward.
Pulling the DIP and blanking and flashing is pretty easy.
Using the Uno as a programmer would lead you to think you could blank a target mega328P MCU.
And also using the IDE with the Uno MCU pulled. Or with dude.
All I see is load EEPROM and Program flash and programming the bootloader.
Zero fill, blanking the chip. Just like a brand new one off of a reel.
Where are the docs and methods on how to do that?
Why don't my selected .hex and .eep files read back the same?
Google was a casual friend on all of those queries.
I have a good array of SMD rework and repair equipment and a "few" years of experience.
Why is the LED flashing on the Mini and how can I find out why and if it is correct or not?
The makefile and configuration for the tester match the features it has. The flash files are included so I don't need to run it.
A lot of questions, yes. Good ones I hope. Somebody has the answers. Really need a few tips and advice.
If there are other components attached to the SPI pins in your tester reprogramming may fail. You need nothing else but your programmer to be connected to the MCU.
I would recommend to solder the new Atmega328 on such an adapter plate and program it, before you solder it in the tester.
Actually these replies are very similar to many others having to to do with the programming difficulties. The photo below shows the pin configuration that I'm using.
Digi-Key might have been just worth the wait and shipping.
It is not the cost of just tossing the tester in the trash. It's what is said can be done easily is not so.
The tester uses an external 8 MHz crystal. The advertised promini I got from Amazon is advertised as having a 16 MHz clock speed.
The crystal is marked AP. And without probing the clock with an oscilloscope, I'm assuming it is in fact 16 MHz.
Could that be an issue? The makefile shows 8 Mhz. Does programming the mini with 16 MHz cause a failure?
I can certainly pull the crystal. Documents of the chip says it uses a native 8 MHz internal clock.
Maybe I missed something. Perhaps the internal clock can be programmed differently.
But what gives? Is there only 1 programmer sketch for the UNO?
If another one is out there could that help?
And the question. Burning just a bootloader to the promini?
Why did it work when I removed the MCU from the Uno?
Something smells fishy. If the Uno has no processor. It can't be a programmer.
Discrepencies in the flash files and what was read back after. What's up with that?
Nothing says anything should be difficult. Then a "put a 10uF electrolytic capacitor across gnd and reset" comes up. No joy on that one.
Atmel Flip comes up. It does not work on the Uno. Same as everyone else.
The flashing LED on the Uno does not happen. Still flashed as a programmer.
Once the promini is hooked up, LED's on both flash.
So, the LED flashing must be coming from the promini? Yes? No?
Can that code be embedded in the bootloader of the promini?
Or is it inside of the eep, eeprom program?
The breakout board looks slick. Tried looking for an actual promini schematic like I have to see is any component would be "getting in the way" of the straight pin-pin of the breakout board.
None of this is stupid stuff. I considered the youtube reply that the bootloader is included in the flash files.
But now I'm led to believe that the bootloader lives in a separate section and has to be flashed as a separate process. But how? Using the Uno as a programmer?
Everyone says how to do it. Everyone says this is how you do it. Everyone makes it seem straight forward.
Nobody says what to do and how to diagnose why you haven't has success.
Some people grip that the promni's they have bought have no bootloader. They just sit there stagnant and dead.
Same procedures. How to flash a bootloader into them. Just do it like this and ba-da-bing.
But it ain't always so. 6 months go by and the post's closed.
Guys and gals. Can I get more than a one line reply to troubleshoot this please??
Edit: And. What's up with the other 6 pin ISP header by the Uno's USB socket?
Can a bootloader bu loaded to the mini with it. Or does bootloader programming only work with a programmer? My Uno as a programmer is being a pain.
So I pulled the crystal from the board. With the mini hooked back up to the uno on the ICSP port. No more LED flash.
Still. With every instruction how to burn a bootloader to the uno. Followed to a tee. No real feeling of success. Set the IDE to use the uno as the programmer. Target as specified. None work.
Poked around at different settings. Finally got something. Breaking the connection by pulling the USB cable from my pc. Most of the readable text disappeared. What gives??
