GPIO-Controlled Network Connection
This example demonstrates how to use a GPIO to control a network connection to a remote server. Once the network connection is open, data can be automatically streamed between Gecko OS and the remote server.
Features Demonstrated
- ioconn.* variables
Method
The Gecko OS
ioconn
feature makes it easy for an MCU, or blackbox electronic system with a serial output, to add network communication with a remote server. A GPIO is assigned as the
ioconn.control_gpio
. Toggling the ioconn control GPIO makes and breaks the network connection to the remote server.
The remote server used in the demonstration is the Silabs test TCP echo server, located online at
test.zentri.com
. The TCP echo server simply echoes any messages back to the client.
A computer, connected via USB to the evaluation board, takes the part of the MCU host system.
To set the level of the ioconn control GPIO high, various techniques are possible. In this demonstration, a switch is used to connect a logic high (3.3V) to the ioconn control GPIO pin. In an actual implementation, the host system toggles the ioconn control GPIO.
This demonstration uses the user LED GPIOs on the module for the ioconn control and status GPIOs. The LEDs are configured so that:
- User LED1 turns on when the ioconn control GPIO is asserted
- User LED2 turns on when a connection with the remote server is established
This demonstration works on a Mackerel, Moray or Medusa evaluation board.
Setup
Connect the switch between the IOC_CTRL and VDD_3V3, using eval board pins as indicated below:
Board | IOC_CTRL (LED 1) | VDD_3V3 | IOC_STATUS (LED2) |
---|---|---|---|
Mackerel AMW004-E03 | GPIO 22: Pin H2-10 | Pin H2-20 | GPIO 21 |
Moray AMW006-E03 | GPIO 16: Pin H8-24 | Pin H7-35 | GPIO 13 |
Medusa AMW007-E03 | GPIO 1: Pin H2-3 | Pin H2-8 | GPIO 4 |
Connect the module via USB to your computer and open a serial terminal console. See Getting Started .
The following assumes that the module is in the default state. To return to the default state, perform a factory reset .
Set up the local Wi-Fi network parameters.
Gecko OS commands | Comments |
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Configure the ioconn variables.
Gecko OS commands | Comments |
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Performing a GPIO-Controlled Host Connection
When the
IOC_CTRL
GPIO is low, the
stream_list
command does not list any TCP client network stream:
> stream_list
! # Type Info
Assert the module
IOC_CTRL
GPIO by setting the switch to ON.
The stream_list command lists the new TCP client network stream:
> stream_list
! # Type Info
# 0 TCPC 107.170.222.80:50007 (22316)
While the
IOC_CTRL
GPIO is still asserted, send a message to the server:
Gecko OS commands | Comments |
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Gecko OS Response |
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Now check if a message has been received in reply:
Gecko OS commands | Comments |
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Gecko OS Response |
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The server's response echoes the message sent.
De-assert the ioconn control GPIO by setting the switch to OFF.
Once again, the stream_list command does not list any TCP client network stream:
> stream_list
! # Type Info
Using Stream Mode
A typical use of the GPIO Controlled Network Connection feature is to allow a device to stream data to and from a server. To demonstrate this, put the module in stream mode:
Gecko OS commands | Comments |
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The module terminal console can no longer send commands to Gecko OS. Try typing at the terminal. There is no response. Characters you type are transparently streamed to the network, which is currently not connected. See Serial Interface, Stream Mode .
Now assert the ioconn control GPIO by setting the switch to on.
All characters received from the remote server appear automatically on the console.
Now type some characters into the module terminal console. Typed characters are echoed (after round-trip network latency) by the Silabs test server.
Supporting Gecko OS Editions and Versions
- Gecko-OS-2.0+
Change Log
Modified | Changes |
---|---|
2014-11-28 | Created |