Skip to contentSkip to navigationSkip to topbar
Rate this Page:

Works with Super SIM: Quectel EG21-G


The Quectel EG21-G module supports LTE Cat 1 (4G), UMTS/HSPA+ (3G), and GSM/EDGE/GPRS (2G) cellular connectivity, and features integrated GNSS. Optimized for IoT applications requiring higher bandwidths than the IoT-oriented 3GPP standard Cat-M1 can accommodate, the EG21-G provides data rates of up to 10Mbps down and 5Mbps up.

(information)

Info


Get started with EG21-G and Super SIM

get-started-with-eg21-g-and-super-sim page anchor

The best way to begin working with the EG21-G is to take advantage of Quectel's UMTS & LTE EVB developer kit(link takes you to an external page). It features powerful and easy‐to‐use tools in an environment specifically designed for the development and testing of cellular and GNSS applications based on any of a variety of Quectel modems, including the EG21-G. Just clip on a test board featuring the modem you're using. The one you need for this guide is the EG21-G-TE-A test board. It's available separately. The kit can be connected to and used with a Windows 10, Linux or macOS computer.

Quectel's UMTS and LTE EVB developer kit features easy‐to‐use tools designed for the development of cellular applications .

The EVB and the separate test board can be purchased from the following suppliers:

EVB

evb page anchor
(information)

Info

Working with the EVB and EG21-G requires a configured Super SIM. If you haven't set up your Super SIM in the Console(link takes you to an external page), please do so now. The Super SIM First Steps guide has help if you need it.

1. Connect the EVB to your computer

1-connect-the-evb-to-your-computer page anchor
  1. Slot a Super SIM into the board's SIM holder. It takes a standard mini-sized SIM, or a micro- or nano-SIM first fitted into an adapter:

    Fit a full-size SIM into the EVB's SIM slot.
  2. Fit the EG21-G test board to the top of the EVB, clipping it to the two connectors in the middle of the EVB. You can place it correctly by aligning the metal panel on the underside of the test board with the four arrows printed on the EVB:

    Align the test card's metal shield with the arrows printed on the EVB.
  3. Connect one of the larger bundled antennas to the test board's uFL connector, marked MAIN. You will need one of the supplied whip adapters to join board and antenna:

    Fit the whip antenna adapter to the test card connector marked main.
  4. Connect the EVB to your computer with the supplied RS232-USB cable. Connect the cable to the EVB's COM (MAIN) connector:

    Clip the chunk RS232 cable to the EVB. The other end fits into a USB port on your computer.
  5. Connect the EVB to a suitable power source, such as a USB AC adapter, and then turn on the EVB by sliding the POWER switch to the position marked ON on the board:

    Connect the EVB's micro USB connector to a five volt AC adapter and push the power switch.
  6. Press the PWRKEY button once to enable the modem test board:

    Press the button marked PWRKEY to power up the modem.

At this point the board's POWER, STATUS, and NET_MODE LEDs should be lit, and the NET_STA LED should be flashing:

Confirm the power, status and net sta LEDs are lit.

2. Access the EVB from your computer

2-access-the-evb-from-your-computer page anchor
LinuxmacOSWindows 10
  1. Open your distribution's terminal app.
  2. Confirm connection with ls /dev/ttyUSB* — you should see a single device listed: /dev/ttyUSB0 . This is the USB-to-serial device you'll use to communicate with the EVB.
  3. Using a serial tool like minicom — you will have to install this separately from source or a package manager like apt — access the board with minicom -o -D /dev/ttyUSB0 .

3. Check your current carrier

3-check-your-current-carrier page anchor

Within minicom or PuTTY, enter the AT command AT+COPS? to see which carrier your EG21-G is connected through:

Check the connected carrier.

The EG21-G supports LTE Cat-1 FDD in bands 1-5, 7-8, 12-13, 18-20, 25-26, 28, TDD in bands 38-41, and GSM at 850, 900, 1800, and 1900MHz.

If you wish to limit communications to LTE only, i.e., to disable 2G (GSM), issue this command:


_10
AT+QCFG="nwscanmode",3

To instruct the modem to initiate data-centric attachments only — ie., not to make voice-oriented circuit-switched attachments too, which is the default — issue:


_10
AT+QCFG="servicedomain",1

All these settings will be applied immediately.

Issue this AT command first to apply the Super SIM Access Point Name (APN):


_10
AT+CGDCONT=1,"IP","super"

By default, the EG21-G will roam automatically, but you can force this by issuing:


_10
AT+QCFG="roamservice",2

These settings will be applied immediately.

Establish a data connection

establish-a-data-connection page anchor

Having set the modem's APN, establish a Packet Data Protocol (PDP) context with the following command:


_10
AT+QIACT=1

The single parameter is the PDP context's ID, in the range 1-16. It should match the first parameter in the above CGDCONT command.

You can also QIACT, in its read form, to get the device's data-connection state — and IP address, if the context is active:


_10
AT+QIACT?
_10
+QIACT: 1,1,1,"100.74.24.186"

The first numeric parameter is the context ID. The second is its state — 1 indicates it is active — and the third is its type: 1 for IPV4 or 2 for IPV6.

Issue the Quectel-specific command


_10
AT+QPING=1,"<TARGET_IP_ADDRESS_OR_NAME>"

to ping a server. Using one of Google's DNS servers as an example, this will yield:


_10
+QPING: 0,"8.8.8.8",32,172,255
_10
+QPING: 0,"8.8.8.8",32,212,255
_10
+QPING: 0,"8.8.8.8",32,376,255
_10
+QPING: 0,"8.8.8.8",32,174,255
_10
+QPING: 0,4,4,0,172,376,233

To issue an HTTP GET request using the EG21-G's built-in HTTP client, run the following commands:

  1. Set the PDP context ID: AT+QHTTPCFG="contextid",1
  2. Enable output of HTTP response headers: AT+QHTTPCFG="responseheader",1
  3. Activate the PDP context if it is not already active: AT+QIACT=1
  4. Set the target URL: AT+QHTTPURL=21 This sets the modem to receive, prompted by the output CONNECT . The first parameter is the number of bytes the modem should expect to receive: it will end input after receiving this number of characters. The value of 21 comes from the URL below. The URL you provide must include the protocol, i.e., http:// .
  5. Upon receiving CONNECT , enter the URL. For example: http://ifconfig.co/ip
  6. Make a GET request: AT+QHTTPGET
  7. View the request: AT+QHTTPREAD

The request will look like this:


_17
HTTP/1.1 200 OK
_17
Date: Thu, 19 May 2022 09:42:03 GMT
_17
Content-Type: text/plain; charset=utf-8
_17
Content-Length: 13
_17
Connection: keep-alive
_17
CF-Cache-Status: DYNAMIC
_17
Report-To: {"endpoints":[{"url":"https:\/\/a.nel.cloudflare.com\/report\/v3?s=9kzHe%2BCGgSnaBOgrEZS6NVZA%2BRV1RQGBlD5gTX5WQGNFtSd4RPnimFfKpQ5e%2FV4DmTsZcyFOZyG}
_17
NEL: {"success_fraction":0,"report_to":"cf-nel","max_age":604800}
_17
Server: cloudflare
_17
CF-RAY: 70dbe160d822595c-IAD
_17
alt-svc: h3=":443"; ma=86400, h3-29=":443"; ma=86400
_17
_17
44.204.32.39
_17
_17
OK
_17
_17
+QHTTPREAD: 0

(warning)

Warning

This example uses a service that returns the IP address of the requester.

Custom HTTP request headers

custom-http-request-headers page anchor

If you need to provide extra HTTP request headers, such Authorization: Basic <API_KEY>, or a custom header required by your server, issue


_10
AT+QHTTPCFG="requestheader",1

to tell the modem to use the custom header that you will provide when you make each request. You will need to create a full HTTP request header separated from your request body by the characters <CR><LF>. Whether you make a POST or a GET request, include a byte-count parameter that totals the header plus the body (POST request) or header alone (GET request). For example, AT+QHTTPGET=60,512 for a 512-byte header (including the end-of-header <CR><LF>). The first parameter, 60, is a timeout. This usually defaults to 60 seconds but must be included if a second parameter is also present.

To issue a secure HTTP GET request using the EG21-G's built-in HTTP client, you follow the same procedure outlined above but with some extra steps included to configure SSL.

  1. Set the PDP context ID: AT+QHTTPCFG="contextid",1
  2. Enable output of HTTP response headers: AT+QHTTPCFG="responseheader",1
  3. Activate the PDP context if it is not already active: AT+QIACT=1
  4. Select the SSL context ID for this PDP context ID: AT+QHTTPCFG="sslctxid",1
  5. Set the SSL version. Choose TLS 1.2: AT+QSSLCFG="sslversion",1,3
  6. Set the SSL cipher suite. Choose all types: AT+QSSLCFG="ciphersuite",1,0xFFFF
  7. For testing, set the SSL verification level to 0, so no CA certificate is required: AT+QSSLCFG="seclevel",0
  8. Set the target URL: AT+QHTTPURL=70 This sets the modem to receive, prompted by the output CONNECT. The parameter is the number of bytes the modem should expect to receive: it will end input after receiving this number of characters. The value of 70 comes from the URL below. The URL you provide must include the protocol, i.e., https:// .
  9. Upon receiving CONNECT , enter the URL. For example: https://twilio-cms-prod.s3.amazonaws.com/documents/super-sim-test.json
  10. Make a GET request: AT+QHTTPGET
  11. View the response: AT+QHTTPREAD

The request will look something like this:


_16
HTTP/1.1 200 OK
_16
Date: Thu, 19 May 2022 10:23:25 GMT
_16
Last-Modified: Thu, 19 May 2022 10:05:25 GMT
_16
Accept-Ranges: bytes
_16
Content-Type: application/json
_16
Server: AmazonS3
_16
Content-Length: 128
_16
_16
{
_16
"userId": 1,
_16
"id": 5,
_16
"title": "laboriosam mollitia et enim quasi adipisci quia provident illum",
_16
"completed": false }
_16
OK
_16
_16
+QHTTPREAD: 0

Perform an HTTP(S) POST

perform-an-https-post page anchor

Sending data from the modem to an Internet-hosted API follows the paths outlined above for the HTTP and HTTPS protocols. The key difference is that you call AT+QHTTPOST instead of AT+QHTTPGET.

Optionally, the QHTTPOST command takes a parameter indicating the amount of data you are sending. The modem uses this to read that number of bytes via the UART over which your application is communicating with it — just as it does with the QHTTPURL command we used earlier. If you are providing a custom HTTP request header, remember to include its length too.

While the EG21-G supports low-power modes for eDRX and PSM, support for these features will vary by visited network and location. The commands to enable each of these settings on the EG21-G are, respectively:


_10
AT+CEDRXS=1
_10
AT+CPSMS=1

Both settings, but especially PSM, can prevent the modem from being accessible through the terminal during its sleep time. It's best to experiment with these features with the modem local. To disable all power saving if needed, send:


_10
AT+CEDRXS=0
_10
AT+CPSMS=0


Reach out for more information

reach-out-for-more-information page anchor

Keen to find out more about how the Quectel EG21-G cellular module can power your IoT product design? Contact Quectel sales(link takes you to an external page) to line up a conversation.

And don't forget, we're always ready to discuss how Super SIM can help you(link takes you to an external page) too.



Rate this Page: