Connect a serial input for Keyboard


We would like to Connect a numeric keypad using USB serial (or RS232/xxx) to the MangOH yellow device to receive user keystroke inputs as a string so that we can process the data on the edge.
Is this currently supported? and if so, what is the easiest and/or best way to achieve this?

The requirement is to capture a numeric input at the edge and send it to the cloud. Any pointers will be appreciated whether we should look at USB to UART or GPIO and also at a high level how this can be achieved.

Thanks in advance

Hi Theo

In order to support a USB keyboard you would need

  1. The Linux driver (might already be built into the WP7702 OS)
  2. A Legato app to handle the USB keyboard data and send it to the Legato Datahub
  3. Access to Sierra’s Edge Octave binary images
  4. The Legato build system

A tricky project.

An alternative is to connect a serial (UART based) keyboard to the mangOH yellow UART1 via the (1V8 logic) IoT expansion board. You will need a voltage level shifter to interface the keyboard with the mangOH - if using an RS232 keyboard you will need an RS232 converter that interfaces with 1V8 logic. In order to achieve this with standard parts off the net you will probably need a RS232 <> 3V3 and 3V3 <> 1V8 level shifter

In Octave you could use the USP protocol to capture the keyboard data and then an edge action to process it

I hope this helps


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Hi Theo,

Are you familiar with out Universal Serial Parser? It is in preview on the 3.0.x releases:

If you are willing to use RS232, then perhaps this will work for you.


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Thank you John and Ian, for the responses. You guys have given me something the work with. I will report back shortly on my progress.

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