ESP RF Test Tool not compatible with native USB on ESP32-S3

[seonroz]

Hi folks,

I'm about to put my ESP32-S3 boards into CE pre-cert, and I was running through the RF Tool steps to ensure everything works as expected before sending stuff to the lab, but it seems the RF Tool is not compatible with running on native USB?

My boards only have native USB broken out, and if I put the board into download mode, I can open the port, and "download" the rf bin to RAM, but then the code fails to work when I try any of the Wifi/BT tests.

If I go into download mode, open the port and "download" the rf test bin to FLASH, it loads successfully, but of course the code wont run unless I press reset. Resetting the board might start the code, but I am unable to open the port any longer, so cannot run any tests.

I was able to connect an external programmer to RX/TX and flash and run the tests like that, but that is not a scenario that will work in the test lab. 1. I cant have wires handing off the board, with external programmers during the test, and 2. the test folks will totally mess it all up.

I want to provide my test lab with some boards for testing that have the firmware already on it, so they only have to load the tool, plug the board in via USB and open the port and run the tests... but this doesn't seem possible using native USB.

Any idea where to go to from here?

Thanks!

[ESP_Sprite]

Suggest you ping sales@espressif.com directly... I imagine the RF test needs to be modified to use the USB-serial-JTAG adapter (which I imagine you are using here, not the OTG that is also available?)

[seonroz]

Suggest you ping sales@espressif.com directly... I imagine the RF test needs to be modified to use the USB-serial-JTAG adapter (which I imagine you are using here, not the OTG that is also available?)

I'm already speaking to sales, and they have spoken to engineering, who have read this post (I hope by now anyway) and are supposed to be getting back to me.

I'm not sure what this bit means "SB-serial-JTAG adapter (which I imagine you are using here, not the OTG that is also available?)"

I'm not using any external adapter (well, I tested with a CP2104 programmer I made, only to check it was working) and I want to only use the native USB for connecting, downloading test firmware and running tests.

[ESP_Sprite]

There's two 'native USB' peripherals on the ESP32S3, which share a PHY. The thing you see by default on a factory-fresh unprogrammed ESP32S3 is the USB-serial-JTAG controller, which functions like an ESP-Prog, but is built-in to the SoC. In software (or by setting eFuses), you can swap this for the DWC-OTG peripheral, which is the same as the USB peripheral in the S2. The USB-serial-JTAG has the advantage that it's independent of software and as such usable in more scenarios, plus it provides JTAG; the OTG has the advantage that it provides DFU update functionality (and it fully programmable). Given the fact that you haven't messed with this too much and it's the default setting, I'm assuming you're talking about the former of the two.

[seonroz]

There's two 'native USB' peripherals on the ESP32S3, which share a PHY. The thing you see by default on a factory-fresh unprogrammed ESP32S3 is the USB-serial-JTAG controller, which functions like an ESP-Prog, but is built-in to the SoC. In software (or by setting eFuses), you can swap this for the DWC-OTG peripheral, which is the same as the USB peripheral in the S2. The USB-serial-JTAG has the advantage that it's independent of software and as such usable in more scenarios, plus it provides JTAG; the OTG has the advantage that it provides DFU update functionality (and it fully programmable). Given the fact that you haven't messed with this too much and it's the default setting, I'm assuming you're talking about the former of the two.

Oh, right! I wasn't away there were 2 different "native USB" peripherals on the S3. I was just assuming it was like the S2. So that's what IO3 is used for on boot, to switch between JTAG via pins and JTAG via USB-serial? - that now makes sense.

So when the S3 is put into "download mode" with IO0/reset, does that now put it into the USB-Serial-JTAG by default?

Anyway, yes it seem that also needs to be added to the RF test Tool, if that is what the device is defaulting to as it's now working right now.

Cheers,

[bobolink]

Seon,
After you get it all straight, a um video on debugging with “JTAG via USB-serial” would be interesting. While you are waiting for production S3s.

[ESP_Sprite]

For what it's worth, you can look up info about the USB-serial-JTAG thing in the ESP32C3. Aside from it sharing the PHY with the OTG peripheral (as the C3 does not have that), the process is the same.

[ESP_Jack]

Sorry for the delay. Using USB to download and run RF test firmware is not tested internally. The issues I can image: 1. USB may use bigger memory block in the ROM, which may cause corrupted when downloading through USB. 2. USB PHY in ESP32S3 impacts the RF performance somehow, it is possible that the USB PHY is disabled in RF test firmware. We will test this internally first, to see what is the root cause and how to fix this.

[ESP_WZH]

Hi, @Seon,
We currently do not provide support for USB Console in the RF_BIN, and we recommend that you use the native UART for testing. If it is necessary to use a USB serial port, we can provide an RF Bin that supports USB Console.

[seonroz]

Hi, @Seon,
The known problems that cause the phenomenon you are experiencing are as follows:

1. In order to avoid the adverse effects of the USB PHY on the RF-related PHY, we have turned off the USB PHY in the RF_BIN you get.
2. The console provided in our current test firmware does not provide support for USB-Serial-JTAG's UART.

Due to the above reasons and other potential problems, we recommend that you use the native UART for testing. If it is necessary to use a USB serial port, we can provide an RF Bin that supports USB Console, but it may take a while.

Thanks for the reply. This is super super upsetting to hear.

I don't have a seperate Serial2UART on my board, I only have native USB, so I'm going to have to supply my test lab with an external programming device and a bunch of wires and instructions to show them how to connect each wire to their corresponding
pins on my board using clipping connectors, and hope they do it right and they don't come off during the tests and they don't mess with the results, considering that adding external wires to my board (especially a GND wire) is adding an antenna to the board that could cause radiated interference.

All of this is going to cost me extra time (and therefore $) for my certification, and that really sucks, and it also introduces a bunch of fail points.

The fact that the USB PHY interferes with the RF is also really concerning to me.