Data is configured and working (redSensorToCloud sends data). Did connect to AT command port, basic commands such as !SELMODE and !MAPUART work, but the AirVantage commands (e.g., +WDSS) return an error.
Are there any AT commands that allow me to set up a packet data call, or do I need to use Legato apps to move data between the I2C port and a cloud destination?
We would recommend using Legato API for doing that.
Finally back.
Done and done. Installed latest FW and platform, things are much better.
One question, how do you forward http traffic between the cell and the UART/console using the framework? Everything goes to the log which is fine for demos. Not so good for shuffling large amounts of data from the cloud to an attached micro.
Thanks!
Another question - do the Legato apps require TCP support for communication? My situation does not have TCP support, it needs to use the UART channel as a simple serial connection. The expectation is to use the Sierra Wireless chip as a bridge, doing all the IP framing and such on the cloud side, while communicating with a micro on the UART side.
Thanks!
Hi griggs,
Can you try to clarify your system architecture. Do you have an external microcontroller attached to a UART of the WP? Or are you using the mt7697 on the mangOH Red as your microcontroller? Does the microcontroller provide some hardware capability that the WP module does not? I’m curious why the microcontroller is necessary in your use case.
Right now I’m using a MangOH Red as a dev board. The “real deal” will be a PIC32 wired to 7603 UART lines. The board and app are custom.
Thanks!
Further info - The WP is simply a way to connect remotely. The PIC connects to multiple other devices using a customer-specified protocol.
One option seems to be write a TCP server program for Linux and have it basically just forward all data to/from the UART connected to the PIC32. I’m guessing that you don’t want it to be totally insecure, so then you need to deal with authentication and encryption which will take a decent amount of effort to get right.
You could use ssh to take care of the authentication/encryption side of things and then just run a command over ssh to deal with the serial port.
Maybe the PIC32 is logging continuously though and you want to retain those logs even if there is no client connected to receive the logs. In that case, it seems like you want to have a continuously running process in Linux that interacts with the serial port and then also allow client(s) to connect periodically to send commands or read logs.
It really depends on what you’re trying to achieve.
The idea is to use the WP76xx as the TCP frame and security “data mule” The HTTP connection would (ideally) use the Legato framework to handle authentication to a remote server, passing data to/from a hardwired UART connection to the PIC32. I don’t care about security between the PIC and the WP - that is a physical security issue I can’t address. I was just hoping I could use the UART line as a wire to the PIC, without needing TCP to get the PIC to talk to the WP. The WP will use standard security for the cell data connection to the remote server.
Thanks!
Connecting the PIC to the WP UART shouldn’t be a problem. Just make sure the UART voltage levels match. Also look at at!mapuart command to control what feature is connected to the UART. You want the one referred to as “Linux application”. I provided the information above from memory. Please verify the details by looking at the AT command document for your module. The AT command guide is on source.sierrawireless.com.
On it - and many thanks!
I plan on using the UART1 interface on the IoT expansion board to send AT commands to the WP8548 chip using an external microcontroller (for now at least. I might use the WP8548 as my main processing unit). I have successfully sent AT commands via the USB interface through a windows terminal app. Is there any configuration I have to do for the AT commands to work through the UART1 interface? I will not have the USB connected obviously while I attempt to send AT commands via UART1 to the WP8548, so was wondering if sending AT commands via the UART1/IoT expansion board will work without any configuration.