andrewju wrote:jhsa wrote:Guys, DO NOT power the radio from the voice module regulator. It will give you problems when flashing the radio as the voice module is also powered.
Can you elaborate on this? Is it something specific to serial communication between the voice module and the 9x?
I'm asking because I think I'm the one who first powered up the 9x mainboard from the voice module's VR. Back then the voice module was connected via LCD lines. I had a radio working this way for more than half a year - regularly updating via avrdude and USBasp. I saw no issues of any kind, it worked just great.
As I said before, I have just replaced the m128 with a m2561.. I then decided to power the radio from the voice module's regulator. It has a L4940 V5, which is a 1.5A low dropout regulator. When flashing with my mySmartUSB Light programmer, it gave error.. But the chip don't like this programmer anyway, don't know why. This one powers the board only when flashing.
The UsbAsp powers the board all the time, and the radio with the voice module ON (Because it is connected to the 5V rail) was rebooting every time it left the splash screen. I decided to proceed with flashing anyway, and I nearly bricked the chip.The radio wouldn't turn on and every attempt to flash it failed.. Wrong signature (The m2561 seems to like this one). I had to flash it again using the -B100 option. That revived it again. Funny that it would read the eeprom Ok but it wouldn't flash.. I still didn't flash it since then as I just installed a new regulator on the radio. Will test later in the evening..
I do think it is important that the Voice Module stays OFF when flashing the radio, or maybe, have the radio powered ON and the voltage turned OFF in the programmer.. I think I tried that after it failed but it didn't work.. Maybe because it was already dead.. I really don't feel like testing the failure possibilities here as I'm not really in the mood to replace the chip again on this radio, and don't know if the mainboard would take another chip change, even using that amazing "Chip Quik" stuff.
Another possibility, is to flash the radio using serial with an FTDI adapter. That can be done as the radio has a bootloader. Maybe I should go back doing that. It takes a bit longer but I feel it is safer. I didn't try it yet with the m2561 though.
I also found out that the Atmega2561 is a little bit temperamental when flashing. Not mentioning that it is quite sensitive to static as well.. Don't even ask..
I didn't see any issues - neither with flashing, nor with static... And I installed quite some 2561's by now...
Something specific I should watch out for?
I had to replace the chip twice. The first one had a bad pin, the one that connects to the "Exit" key.. Also it would always give a wrong signature. It had some kind of identity disorder
I managed to flash it using AvrStudio, and also change the fuses, but the signature problem never went away. My guess is that it was zapped with static. Maybe by me, or by the fact it came on a piece of cardboard and held to it with tesa tape..