problems migrating ESP-Modem from 2020-version to 1.0.5 (IDFGH-11815)

[JB-DX]

problems migrating ESP-Modem from 2020-version to 1.0.5 (IDFGH-11815)

[david-cermak]

Ad1) need to add a urc handler, a planned feature for modem_v1.2. This library also supports it, but it involves using some advanced c++ API: you can check this example:

esp-protocols/components/esp_modem/examples/modem_console/main/modem_console_main.cpp

Lines 374 to 378 in 7d0eb5c

	ESP_LOGI(TAG, "Adding URC handler");
	dce->set_on_read(handle_urc);
	} else {
	ESP_LOGI(TAG, "URC removed");
	dce->set_on_read(nullptr);

Ad2) You can also create a custom command or handler in this library. For example:

    std::string output;
    auto ret = dce->command("at+cpbf=\"user\"\r", [&output](uint8_t *data, size_t len) {
        std::string_view response((char *) data, len);
        if (response.find("OK") != std::string::npos) {
            output = response;
            return command_result::OK;
        }
        return command_result::TIMEOUT;
    }, 1000);

Maybe the default esp_modem_at() command should return everything, not just the last line (but I believe this per line tokenization is useful in most cases, as it filters out potential echo's and garbage).

[JB-DX]

Thanks for your suggestions!
My app is written in C, I can't convert it to C++
How can I set_on_read() from C? dce->set_on_read() obviously does not compile.

Yes I also was thinking that esp_modem_at() would return everything, but your concerns are valid too.
For multiline reponses esp_modem_at() either needs the additional parameter accept_multi_line
or a separate function esp_modem_at_multiline() so esp_modem_at() can be left unchanged.

[david-cermak]

I'm sorry, I don't really have a good suggestion for C right now (other than create a custom DCE as in the console example and wrap it in C-API)

dce->set_on_read() obviously does not compile.

It does compile in that example, but as said above -- uses some C++ magic to conveniently override set_on_read() in

esp-protocols/components/esp_modem/examples/modem_console/main/my_module_dce.hpp

Lines 67 to 81 in 7d0eb5c

	void set_on_read(esp_modem::got_line_cb on_read_cb)
	{
	if (on_read_cb == nullptr) {
	handling_urc = false;
	handle_urc = nullptr;
	dte->on_read(nullptr);
	return;
	}
	handle_urc = std::move(on_read_cb);
	dte->on_read([this](uint8_t *data, size_t len) {
	this->handle_data(data, len);
	return command_result::TIMEOUT;
	});
	handling_urc = true;
	}

For multiline reponses esp_modem_at() either needs the additional parameter accept_multi_line separate function esp_modem_at_multiline() so esp_modem_at() can be left unchanged.

Yes, I'd probably add a new function, as you proposed, which could be used more universally. I would also remove the trailing \r here, so the new function could be used to send any kind of characters, e.g. the +++:

esp-protocols/components/esp_modem/src/esp_modem_command_library.cpp

Lines 393 to 394 in 7d0eb5c

	std::string at_command = cmd + "\r";
	return generic_get_string(t, at_command, out, timeout);

[JB-DX]

I managed to add a esp_modem_set_read_cb() in C and that works.
When will v1.2 available?

Another problem:
How can I reconnect to PPP ? I'm using SIM800.
After an established connection I call esp_modem_set_mode(dce, ESP_MODEM_MODE_COMMAND)
and later on (it can be hours later)
esp_modem_set_mode(dce, ESP_MODEM_MODE_DATA);

But that results just in a "User interrupted event" and it doesn't get connected.

The SIM800 sends:

CONNECT
~ÿ}#À!}!}!} }2}"}&} }*} } }#}$À#}'}"}(}"Uƒ~~ÿ}#À!}#}$} }*}"}&} }*} } t"~~ÿ}#À!}!}"} }.}"}&} }*} } }'}"}(}"ÐÓ~~ÿ}#À!}"}%} }4}"}&} }*} } }%}&áÏFˆ}'}"}(}"}=}(~~€!����À¨þþHÌ~~€!����-��àB~~ÿ�À!���…r~
NO CARRIER

A similar question right at the first connection-try after reset:
If it can't get a PPP connection because the provider has no capacity, I get IP_EVENT_PPP_LOST_IP
How can I start a retry? Setting ESP_MODEM_MODE_DATA doesn't work.
Do I have to destroy and re-create the DCE each time? That sounds a bit awkward.

[JB-DX]

Now I got it running. The reason was the missing APN

[david-cermak]

Thanks for the update!

When will v1.2 available?

I'm currently getting ready for v1.1, should be available next week or so,.
Version v1.2 would add a few features, so I think it should be ready sometime in Feb/March. As for the URC handler, its not a big change and I think I could get it working after the 1.1 release.

[david-cermak]

Closing, as I think all questions have been answered. Please reopen or create new issues if it's not the case.

[mettz]

Sorry @JB-DX, I have your same issue regarding the URC handler and set_read_cb stuff and I can't convert my app to c++, too. Could you please share your esp_modem_set_read_cb function implementation? Because I'm not able to make mine work

[JB-DX]

I assumed that the URC handler would have been implemented by now, but I can't find it.

in esp_modem_c_api.cpp I added this:

extern "C" esp_err_t esp_modem_set_read_cb(esp_modem_dce_t *dce_wrap, esp_modem_terminal_read_cbt read_cb)
{
    if (dce_wrap == nullptr || dce_wrap->dce == nullptr || dce_wrap->dte == nullptr) {
        return ESP_ERR_INVALID_ARG;
    }
    if (read_cb) {
        dce_wrap->dte->on_read([read_cb](uint8_t *line, size_t leng) {
           read_cb(line, leng);
            return command_result::TIMEOUT;  
        });
    } else {
        dce_wrap->dte->on_read(nullptr);
    }
    return ESP_OK;
}

and in esp_modem_c_api_types.h add this:
esp_err_t esp_modem_set_read_cb(esp_modem_dce_t *dce_wrap, esp_modem_terminal_read_cbt read_cb);