Custom ESP32 Board Programming
Posted: Tue Feb 18, 2020 4:33 pm
Hi guys 
,
I'm working with a custom PCB using the ESP32-WROOM-32D module. I've got it running the default code successfully, and it spits out the expected stuff over serial (top of attached image).
I'm now trying to connect to it via esptool.py and am having some issues. I'm pretty confident the boot strap pins are correct as I am receiving "rst:0x4 (OWDT_RESET),boot:0x6 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_FEO_V2))" etc. over serial when resetting the chip (bottom of attached image). However, after receiving this esptool.py fails with the famous "Timed out waiting for packet header" error.
I've checked with a scope and while the chip sends a serial transmission on reset, it definitely does not send anything back to esptool once it has been sent something. Esptool is sending stuff (again confirmed via scope). I have checked wiring several times (originally I was getting nothing at all because I had the serial wires the wrong way around so you know...).
I do have a particularly weird setup - I forgot to add a serial to usb converter on my PCB, so I'm connecting using an mbed as a middle man - the code for the mbed is pretty simple, hold the relevant boot strapping pins up, and then transfer anything received from usb to serial and vice versa (at 115200 baud). I've also tried holding the pins up, restarting the esp32 and then lowering them, no difference was made.
,I'm working with a custom PCB using the ESP32-WROOM-32D module. I've got it running the default code successfully, and it spits out the expected stuff over serial (top of attached image).
I'm now trying to connect to it via esptool.py and am having some issues. I'm pretty confident the boot strap pins are correct as I am receiving "rst:0x4 (OWDT_RESET),boot:0x6 (DOWNLOAD_BOOT(UART0/UART1/SDIO_REI_FEO_V2))" etc. over serial when resetting the chip (bottom of attached image). However, after receiving this esptool.py fails with the famous "Timed out waiting for packet header" error.
I've checked with a scope and while the chip sends a serial transmission on reset, it definitely does not send anything back to esptool once it has been sent something. Esptool is sending stuff (again confirmed via scope). I have checked wiring several times (originally I was getting nothing at all because I had the serial wires the wrong way around so you know...).
I do have a particularly weird setup - I forgot to add a serial to usb converter on my PCB, so I'm connecting using an mbed as a middle man - the code for the mbed is pretty simple, hold the relevant boot strapping pins up, and then transfer anything received from usb to serial and vice versa (at 115200 baud). I've also tried holding the pins up, restarting the esp32 and then lowering them, no difference was made.
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