Falha inconsistente do bootloader ATMEGA328P
Estou criando um carregador sem fio com um microcontrolador nele.
Montei 3 placas. Um deles tem um microcontrolador que funciona bem - queima o bootloader e carrega o esboço do código perfeitamente. No entanto, tenho duas outras placas - mesmos componentes que não funcionam. O bootloader falha com as seguintes mensagens:
Primeira Tábua
System wide configuration file is "/home/bem22/tools/arduino-1.8.10/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "/home/bem22/.avrduderc"
User configuration file does not exist or is not a regular file, skipping
Using Port : /dev/ttyUSB0
Using Programmer : stk500v1
Overriding Baud Rate : 19200
AVR Part : ATmega328P
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 20 4 0 no 1024 4 0 3600 3600 0xff 0xff
flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
Programmer Type : STK500
Description : Atmel STK500 Version 1.x firmware
Hardware Version: 2
Firmware Version: 1.18
Topcard : Unknown
Vtarget : 0.0 V
Varef : 0.0 V
Oscillator : Off
SCK period : 0.1 us
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.02s
avrdude: Device signature = 0x000000 (retrying)
Reading | ################################################## | 100% 0.02s
avrdude: Device signature = 0x000000 (retrying)
Error while burning bootloader.
Reading | ################################################## | 100% 0.02s
avrdude: Device signature = 0x000000
avrdude: Yikes! Invalid device signature.
Double check connections and try again, or use -F to override
this check.
avrdude done. Thank you.
Segunda Placa
System wide configuration file is "/home/bem22/tools/arduino-1.8.10/hardware/tools/avr/etc/avrdude.conf"
User configuration file is "/home/bem22/.avrduderc"
User configuration file does not exist or is not a regular file, skipping
Using Port : /dev/ttyUSB0
Using Programmer : stk500v1
Overriding Baud Rate : 19200
AVR Part : ATmega328P
Chip Erase delay : 9000 us
PAGEL : PD7
BS2 : PC2
RESET disposition : dedicated
RETRY pulse : SCK
serial program mode : yes
parallel program mode : yes
Timeout : 200
StabDelay : 100
CmdexeDelay : 25
SyncLoops : 32
ByteDelay : 0
PollIndex : 3
PollValue : 0x53
Memory Detail :
Block Poll Page Polled
Memory Type Mode Delay Size Indx Paged Size Size #Pages MinW MaxW ReadBack
----------- ---- ----- ----- ---- ------ ------ ---- ------ ----- ----- ---------
eeprom 65 20 4 0 no 1024 4 0 3600 3600 0xff 0xff
flash 65 6 128 0 yes 32768 128 256 4500 4500 0xff 0xff
lfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
hfuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
efuse 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
lock 0 0 0 0 no 1 0 0 4500 4500 0x00 0x00
calibration 0 0 0 0 no 1 0 0 0 0 0x00 0x00
signature 0 0 0 0 no 3 0 0 0 0 0x00 0x00
Programmer Type : STK500
Description : Atmel STK500 Version 1.x firmware
Hardware Version: 2
Firmware Version: 1.18
Topcard : Unknown
Vtarget : 0.0 V
Varef : 0.0 V
Oscillator : Off
SCK period : 0.1 us
avrdude: AVR device initialized and ready to accept instructions
Error while burning bootloader.
Reading | ################################################## | 100% 0.02s
avrdude: Device signature = 0xff007f
avrdude: Expected signature for ATmega328P is 1E 95 0F
Double check chip, or use -F to override this check.
avrdude done. Thank you.
Para a placa posterior, geralmente gero device signature 0xffffff ou 0xfff000 ou 0x000fff ou 0x00ff00 etc.
Para as placas 1 e 2, verifiquei as conexões manualmente (do pino QFN ao Arduino ISP) usando um multímetro. As tensões também estão ok - a placa fica normal 3v3.
O único medo para mim é ter queimado os chips durante a soldagem. Usei fio de solda 60/40 e estação de solda a 300 graus. Isso é muito alto? O tempo de contato foi relativamente baixo (menos de 5 segundos).
Aqui estão algumas fotos com a minha configuração: [![digite a descrição da imagem aqui][1]][1] [![insira a descrição da imagem aqui][2]][2]
E aqui está o meu esquema: [![digite a descrição da imagem aqui][3]][3]
Alguma pista do porquê? [1]:https://i.stack.imgur.com/pUEs3.jpg[2]:https://i.stack.imgur.com/R9LLc.jpg[3]:https://i.stack.imgur.com/F832p.png
Respostas
No final, este foi um problema de solda. Não respeitei vários cuidados ao projetar a prancha.
Por exemplo, usei vias nos pads já curtos e isso aumentaria a tensão superficial da solda líquida, não permitindo que ela se ligasse ao cobre.