Heltec V3 with ESP32 S3 works over CP210x but not over USB JTAG.

[MichaelPWalter]

The Heltec V3 comes with the ESP32 S3 which does not seem to be explicitly supported yet. Communication over the USB port utilizes the CP210x so it works. The S3 specifically has an additional USB JTAG interface which is exposed over the GPIO headers so connection would be more convenient.
D+ is located on GPIO Pin 20 and D- on GPIO Pin 19. Power HAS to be provided over the 5v rail, not Ve.

Is there a way to establish a solid connection via the GPIO pins ? I do sometimes get a response using meshtastic --noproto but after the initial header it's always completely silent. Let me know what i can do to help.

[MichaelPWalter]

I've analyzed the chip in accordance to /info/ubuntu/diy.txt as follows. This can be seen as /info/ubuntu/heltec_v3.txt

`lsusb

Bus 001 Device 009: ID 303a:1001 Espressif USB JTAG/serial debug unit
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb -d 303a: -v

Bus 001 Device 009: ID 303a:1001 Espressif USB JTAG/serial debug unit
Couldn't open device, some information will be missing
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 239 Miscellaneous Device
bDeviceSubClass 2
bDeviceProtocol 1 Interface Association
bMaxPacketSize0 64
idVendor 0x303a
idProduct 0x1001
bcdDevice 1.01
iManufacturer 1 Espressif
iProduct 2 USB JTAG/serial debug unit
iSerial 3 48:CA:43:59:06:20
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 0x0062
bNumInterfaces 3
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xc0
Self Powered
MaxPower 500mA
Interface Association:
bLength 8
bDescriptorType 11
bFirstInterface 0
bInterfaceCount 2
bFunctionClass 2 Communications
bFunctionSubClass 2 Abstract (modem)
bFunctionProtocol 0
iFunction 0
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 2 Communications
bInterfaceSubClass 2 Abstract (modem)
bInterfaceProtocol 0
iInterface 0
CDC Header:
bcdCDC 1.10
CDC ACM:
bmCapabilities 0x02
line coding and serial state
CDC Union:
bMasterInterface 0
bSlaveInterface 1
CDC Call Management:
bmCapabilities 0x03
call management
use DataInterface
bDataInterface 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 10 CDC Data
bInterfaceSubClass 2
bInterfaceProtocol 0
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x01 EP 1 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 2
bAlternateSetting 0
bNumEndpoints 2
bInterfaceClass 255 Vendor Specific Class
bInterfaceSubClass 255 Vendor Specific Subclass
bInterfaceProtocol 1
iInterface 0
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x02 EP 2 OUT
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x83 EP 3 IN
bmAttributes 2
Transfer Type Bulk
Synch Type None
Usage Type Data
wMaxPacketSize 0x0040 1x 64 bytes
bInterval 1

esptool.py chip_id

esptool.py v4.7.0
Found 1 serial ports
Serial port /dev/ttyACM0
Connecting...
Detecting chip type... ESP32-S3
Chip is ESP32-S3 (QFN56) (revision v0.2)
Features: WiFi, BLE, Embedded Flash 8MB (GD)
Crystal is 40MHz
MAC: 48:ca:43:59:06:20
Uploading stub...
Running stub...
Stub running...
Warning: ESP32-S3 has no Chip ID. Reading MAC instead.
MAC: 48:ca:43:59:06:20
Hard resetting via RTS pin...

`

[Abdull]

did you solder those empty resistor pads on the PCB in order to have the ESP32-S3's USB D+ and D- package leads connected to the header pins? Because at least for the Heltev LoRa V3, V3.1, and V3.2 hardware revisions, this must be done first - and probably the resistors that hook up the USB-C port's D+ and D- to the CP2102 USB UART chip have to be removed, otherwise there would be three USB devices (the ESP32-S3, the CP2102, and the USB-C connected devices) competing for a bus ressource that can only handle exactly two.

[MichaelPWalter]

I will have to try that :)

[Abdull]

via https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA_V3(Rev1.1).pdf :

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via https://resource.heltec.cn/download/WiFi_LoRa_32_V3/HTIT-WB32LA(F)_V3.1_Schematic_Diagram.pdf :

Note: don't confuse the different pins and signals labeled with "19" and "20": 19 and 20 are reused for IC-specific pins as well.

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via https://docs.espressif.com/projects/esp-idf/en/v5.3.1/esp32s3/api-guides/jtag-debugging/configure-builtin-jtag.html :

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ESP32-S3 datasheet (includes further information about steps required to set up USB JTAG): https://www.espressif.com/sites/default/files/documentation/esp32-s3_datasheet_en.pdf .