ESP32 Forum

Hello all,
I developed a custom board based on ESP32 interfaced with LAN 8720 Ethernet module. The Board works fine with ESP32-WROOM-32D but fails on ESP32-WROOM-32U. I have referred the schematic for designing LAN interface with some changes(included LED's for indication and different Ethernet connector) https://www.waveshare.com/w/upload/0/08 ... ematic.pdf
How do I troubleshoot the same?

How many units did you test?

@WiFive I have tested 4 units of wroom32u with LAN module and 6 units of Wroom32d with LAN

In what way does it fail? What are the logs?
There is wroom-32u version of this product
https://www.olimex.com/Products/IoT/ESP ... e-hardware

@WiFive I checked the hardware design of OLIMEX ESP32 Gateway .They have used LAN8710 instead of 8720.

Talking about logs, I uploaded Ethernet example from https://github.com/espressif/esp-idf/tr ... t/ethernet
and serial logs are as follows


I (599) cpu_start: Pro cpu up.
I (603) cpu_start: Application information:
I (608) cpu_start: Project name: ethernet_demo
I (613) cpu_start: App version: 1
I (618) cpu_start: Compile time: 17:09:13
I (623) cpu_start: Compile date: Mar 11 2019
I (628) cpu_start: ESP-IDF: v3.3-beta1-328-gabea9e4c0-dirty
I (635) cpu_start: Starting app cpu, entry point is 0x40080e5c
0x40080e5c: call_start_cpu1 at C:/msys32/home/users/esp/esp-idf/components/esp32/cpu_start.c:265

I (0) cpu_start: App cpu up.
I (646) heap_init: Initializing. RAM available for dynamic allocation:
I (652) heap_init: At 3FFAE6E0 len 00001920 (6 KiB): DRAM
I (658) heap_init: At 3FFB4080 len 0002BF80 (175 KiB): DRAM
I (665) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM
I (671) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (677) heap_init: At 40088528 len 00017AD8 (94 KiB): IRAM
I (684) cpu_start: Pro cpu start user code
I (31) cpu_start: Starting scheduler on PRO CPU.
I (0) cpu_start: Starting scheduler on APP CPU.
I (33) eth_example: Power On Ethernet PHY
I (43) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (53) emac: emac reset done
I (53) eth_example: Ethernet Started
I (4053) eth_example: Ethernet Link Up


The event is not going beyond "Link up" in esp32-wroom32u based boards
whereas in wroom-32d i get following output

I (0) cpu_start: App cpu up.
I (645) heap_init: Initializing. RAM available for dynamic allocation:
I (652) heap_init: At 3FFAE6E0 len 00001920 (6 KiB): DRAM
I (658) heap_init: At 3FFB4080 len 0002BF80 (175 KiB): DRAM
I (664) heap_init: At 3FFE0440 len 00003AE0 (14 KiB): D/IRAM
I (671) heap_init: At 3FFE4350 len 0001BCB0 (111 KiB): D/IRAM
I (677) heap_init: At 40088528 len 00017AD8 (94 KiB): IRAM
I (683) cpu_start: Pro cpu start user code
I (30) cpu_start: Starting scheduler on PRO CPU.
I (0) cpu_start: Starting scheduler on APP CPU.
I (33) eth_example: Power On Ethernet PHY
I (43) system_api: Base MAC address is not set, read default base MAC address from BLK0 of EFUSE
I (53) emac: emac reset done
I (53) eth_example: Ethernet Started
I (4053) eth_example: Ethernet Link Up
I (7033) event: eth ip: 192.168.29.25, mask: 255.255.255.0, gw: 192.168.29.1
I (7033) eth_example: Ethernet Got IP Addr
I (7033) eth_example: ~~~~~~~~~~~
I (7033) eth_example: ETHIP:192.168.29.25
I (7043) eth_example: ETHMASK:255.255.255.0
I (7043) eth_example: ETHGW:192.168.29.1
I (7053) eth_example: ~~~~~~~~~~~

Only difference between two boards is module(wroom32d and wroom32u).rest all designs are same.

I'm surprised there's any difference between 32U and 32D.

We have a board with a wroom-32U with a LAN8720 working ok. We just followed the LAN8720 design guidelines / reference designs and it worked. Never tried the board with a 32D through.

robertson80 wrote: ↑

Sun Mar 24, 2019 8:35 am

I'm surprised there's any difference between 32U and 32D.

We have a board with a wroom-32U with a LAN8720 working ok. We just followed the LAN8720 design guidelines / reference designs and it worked. Never tried the board with a 32D through.

@robertson80 the design worked. there were few glitches in the hardware which were later rectified and implemented successfully.