WiFi Controlled Wheelchair

This is post is a follow on to my original wheelchair hack at: https://bobparadiso.com/2014/10/28/ble-controlled-wheelchair/
That post has all the info about the motor driver’s communication protocol(timing, checksum, etc).

I’ve been recently been acquainted TI’s CC3200 WiFi chip and wanted to post an example of using it. One thing I like about this chip is that it includes an ARM Cortex-M4 so in addition to handling the WiFi communication you can use it run your application code and/or serve web pages without needing a separate MCU. Another thing I like about it is that it can run as a wireless Access Point. In other words, even if without any other WiFi network accessible, your smartphone or computer could connect directly to it, and be served a page to interact with. All of this is also without having anything extra installed on your device, just your web browser is enough.

Here’s where I got with it:

To test this, similar to my previous wheelchair post I only had to add 2 components to replace the joystick: a step down converter for the voltage(that blue board tuned to bring the 24V down to 5V), and the MCU board. For this test I used the CC3200 Launchpad evaluation board, handy since it breaks out all the pins, has a USB connector for programming and debugging, and buttons and some indicator LEDs built in, and the antenna. I setup the CC3200 running as an Access Point named “Wheelchair”. Once connected, you can hit “wheelchair.com” which will bring up the control page for the wheelchair(only if you’re connected to the Wheelchair Access Point). That page has some buttons to manually open or close a WebSocket connection. Once the websocket is open your device will stream the position of the onscreen joystick. The CC3200 receives this over the websocket and controls the motors accordingly.




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