ESP32 as HOST MCU

[alberk8]

Is it possible to have an example implementation where ESP32 is use as the HOST and ESP32-C3 as the client for both Wifi and BLE with SPI and/or Uart. Thank you.

[ajita02]

Hi @alberk8, Its definitely possible. Please follow this documentation. You need to port MCU example according to ESP32.

[alberk8]

Hi @alberk8, Its definitely possible. Please follow this documentation. You need to port MCU example according to ESP32.

Thank you for the prompt reply. A working example would be much appreciated.

[ajita02]

Hi @alberk8,

Configuring ESP as host and client doesn't make helpful use case for end users, as ESP already have WiFi-BT functionality. You can take help of MCU implementation for porting application to ESP32.

Thanks, Ajita

[alberk8]

I might looked not useful but it gives a testable scenario before moving to implementing on other MCU. I would like to call it a reference implementation.

[copercini]

I think it's interesting to use an ESP32 with an ESP32-C5 for example, then it's possible to use Ethernet from the standard ESP32 and Wi-Fi 5GHz from ESP32-C5

[alberk8]

I think it's interesting to use an ESP32 with an ESP32-C6 for example, then it's possible to use Ethernet from the standard ESP32 and Wi-Fi 5GHz from ESP32-C6

There is a use case that I want to use. On an ESP32 I would setup an Soft AP accepting client connection and on a C3 where it connects to an STA to push data up to a cloud. Well you might say that this already works with one ESP32. Yes but you cannot have high volume traffic when both STA and AP is running on one hardware.

[mantriyogesh]

We can do it if you feel the use case helps you. Spare us two week time to implement and test, considering current priority items.

[alberk8]

We can do it if you feel the use case helps you. Spare us two week time to implement and test, considering current priority items.

Hi @mantriyogesh , Thank you for the prompt reply. Please proceed with the reference implementation. Thank you again.

[mantriyogesh]

Hello @alberk8

I have done PoC for this & arping is working fine. Right now I have added high debug prints and some in place changes for porting from cmsis to freertos (ESP operated on idf based freertos). If impatient & If you want to try the solution (to try), let me know.

I am going to add this in supported host MCU list itself, once I cleanup and add some more code.

[alberk8]

Thanks for the update. I can wait for the final product.

[mantriyogesh]

Hello @alberk8

Edit 1: Added other supported ESP chipset connections

We are parking this activity for some time, because of another high priority items to take. Anyway, the ESP32 as host is working fine. The station and softAP should work with ESP32 as Host (on SPI transport)

1. Select any two chips which you have, one as host and one as slave.

For example, ESP32 as Host and ESP32-C3 as slave.

You can also use two same kind of chipsets also.

For example, You have two ESP32-S3. One of them is Master and other as slave.

Once you choose master and slave chipset, Please make a note of which one is slave and which one is host (just so as not to get confused later!)

1. Slave flashing Flash esp_hosted_fg/esp/esp_driver/network_adapter in slave chipset using esp-idf release/v5.0 or master branch (use main documentation) Host side flashing covered ahead.

2. Connections between Host & Slave

Function	ESP32	ESP32-C2 / ESP32-C3 / ESP32-C6	ESP32-S2 / ESP32-S3	Function
CS0	IO14	IO10	IO10	CS0
SCLK	IO15	IO06	IO12	SCLK
MISO	IO13	IO02	IO13	MISO
MOSI	IO12	IO07	IO11	MOSI
GND	GND	GND	GND	GND
Handshake	IO02	IO03	IO02	Handshake
Data ready	IO04	IO04	IO04	Data ready
Slave reset	M: IO05 / S: EN	M: IO05 / S: RST	M: IO05 / S: RST	Slave reset

M: Master side pin S: Slave side Pin

3. Files to note: esp_hosted_fg/host/microcontrollers/port/esp_hosted_config.h - contains the common config

4. Building a. Apply patch ESP32_as_Host_over.patch on git commit, fe0b10584417629908cee8141699c2f35ea05a25 b. setup idf release/v5.0 on your laptop c. build and flash host

   cd esp_hosted_fg/host/microcontrollers/port/esp/esp32
   idf.py set-target <host_esp_chipset>
   idf.py flash monitor

   can be one from esp32, esp32c2, esp32c3, esp32c6, esp32s2, esp32s3

5. Known issues (will solve these once resume this activity)

a. Flashing either chipset when both chipsets are connected in usb is not possible. This mostly would be due to using bootstrap pin GPIO02 as handshake. workaround: flash slave ESP first and detach, flash host ESP with idf.py flash monitor & then while flashing in progress, attach SLAVE ESP correct fix: try changing HANDSHAKE Pin from GPIO02 to some other non bootstrapping pin

b. reset pin is not working slave reset (c3 reset) is not happening. Should be small issue to fix, but did not get the time to look into this.

c. Linux and STM32 is broken to build. Basically, the changes are done from system and design point of view. But in meantime, I have broken STM32 an Linux build system due to change of directory structure. ESP32 as host will not face any issue although for building.

6. Limitations - We have not yet tried to integrate SDIO transport

Please do try and let us know, if the things work at your place.

[alberk8]

Thank you for the detailed update.

[mantriyogesh]

With fe0b10584417629908cee8141699c2f35ea05a25 as base ESP-Hosted commit,

ESP chipset as host some more updates: lwip_ported_ESP32_as_Host_SerialMsgs_changed.patch

This patch working lwip stack working with station and softap mode. memcpy etc could be optimised ahead.

Please note:

1. this has changed the base Serial messages and not compatible with the Hosted master. What it means, you need to use slave and host code both from this patch.
2. host/microcontrollers/drivers/netif will showcase the lwip port according to ESP-IDF standards

idf.py monitor can be used to change the SPI (and all ESP-Hosted) pins at host ESP.

[alberk8]

@mantriyogesh, Where can I find the completed ESP32 as a host example? Thank you.

[mantriyogesh]

Did you try https://github.com/espressif/esp-hosted/issues/186#issuecomment-1490201090?

[mantriyogesh]

You can refer to the upto date code base. esp_as_slave+esp_as_host: h1.8jul23.tgz

Pins for ESP32 <- SPI -> ESP32 Slave & Host ESP32: MOSI : 13 MISO: 12 CLK: 14 CS: 15 HS: 26 DR : 4 GND

Host pin 5 <--> Slave EN

Flashing procedure

Other esp chipsets are also supported. pins could be found from idf.py menuconfig at both slave and host.

idf supported: release/v5.1 ESP chipsets, esp32, esp32-c2/c3/c6/s2/s3 should be supported by this.

1. disconnect both slave & host
2. connect slave esp

   $ cd esp_hosted_fg/esp
   $ idf.py -p <serial_port_slave> menuconfig 
   # Navigate to  'Example Configuration'. please check pins to be used at slave, hosted config, spi config etc using this command.
   $ idf.py -p <serial_port_slave> flash monitor

3. disconnect slave esp from laptop
4. connect host esp to laptop
5. in new terminal window,

   $ cd esp_hosted_fg/host/microcontrollers/port/esp/examples/wifi/iperf
   $ idf.py -p <serial_port_host> menuconfig
   # Navigate to  'Example Configuration'. please check pins to be used at host esp, hosted config, spi config etc using this command.
   $ idf.py -p <serial_port_host> flash monitor

6. connect back slave esp. logs should start in slave terminal. if not started, run

   $ idf.py -p <serial_port_slave> monitor

Some points to note:

1. LWIP performance is not great, looking into this issue
2. SPI as transport is supported till now

[mantriyogesh]

GPIO for ESP as slave and ESP as Host with SPI transport to work with https://github.com/espressif/esp-hosted/issues/186#issuecomment-1626859260

ESP32	ESP32-S2/S3	ESP32-C2/C3/C6	Function
13	11	7	MOSI
12	13	2	MISO
14	12	6	CLK
15	10	10	CS
26	17	3	Handshake
4	4	4	Data Ready
GND	GND	GND	Ground
5	5	5	Slave Reset

[mantriyogesh]

Latest fixes for stable LWIP :

On https://github.com/espressif/esp-hosted/commit/fe0b10584417629908cee8141699c2f35ea05a25 , apply ESP_as_Host_with_stable_LWIP.patch