UART Comms

Posted on Fri 30th, May 2014

• #1

StuntMonkeh

Is it possible to program the Espruino without a USB cable?

For instance if I were to connect the Espruino UART4 (Pins C10 & C11) to a Raspberry Pi would I be able to send the Javascript commands to the Espruino without using a USB cable?
• #2

DrAzzy

Yes - but I think you'd need to write code to move the console to UART4. I haven't tried this, except on UART1.

If you use UART1 (A9/A10), it will automatically use that as the console if USB isn't connected (those are the same pins used by the HC-05 bluetooth<->serial module, if you install it, allowing you to connect over bluetooth and control it that way).
• #3

StuntMonkeh
I see what you mean. The only reason for choosing UART4 is that those pins are UART only and no PWM.
So to use UART4 I guess I need to drop in something like this:
```
Serial4.setup(9600, {rx:C11,tx:C10});
```
• #4

DrAzzy

I think you also need to do:

Serial4.setConsole()
• #5

Gordon
You may need something like this - to ensure that at startup, Espruino always swaps over to Serial4:
```
Serial4.setup(9600, {rx:C11,tx:C10});
function onInit() {
  Serial4.setConsole();
}
```

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