Serial Peripheral with MDBT42Q

[espruino-discuss]

Posted at 2019-12-12 by user106663

Hi I see the MDBT42Q Breakout uses the only UART for serial console.

I'd like to use an RN2483A (I've a breakout board from tindie [1] on the way)

Will it be possible in JS code to claim the UART for interfacing with this peripheral, and use the BLE interface for consoe/firmware/script upload.

Some thoughts:
a) I notice it checks the status of the MCU:RX <-- TX line.
I assume the RN2483 isn't going to boot up with TX high (but that could be a gross presumption)

b) Can the BLE radio be disabled in code? I would only need the radio on for config/update, it'd be nice to shut the radio down.

c) What's the deep sleep current like on the MDBT42Q breakout compared to the Pico.
I was going to use the pico but some off the PPI features look really interesting.

Thanks.

R

[1] https://www.tindie.com/products/drazzy/rn2483-breakout-bare-board/

[gfwilliams]

Posted at 2019-12-12 by @gfwilliams

Will it be possible in JS code to claim the UART

Yes, just move the console out the way. Bluetooth.setConsole(1) is fine for this.

I assume the RN2483 isn't going to boot up with TX high (but that could be a gross presumption)

It probably will do, but that's no problem.

Can the BLE radio be disabled in code?

Yes, NRF.sleep - but it uses so little power it makes sense to keep it on

What's the deep sleep current like on the MDBT42Q

20uA when advertising, 10uA or under when asleep on the breakout board. On the module itself (without the voltage regulator) you're looking at 3uA or less.

[espruino-discuss]

Posted at 2019-12-12 by AkosLukacs

Some info about the Serial console in the MDBT42Q
Yes, you can disable the UART console with Bluetooth.setConsole(true).

a: "Note: Serial1 is not enabled by default because it requires the high speed oscillator to stay on, which increases power draw a huge amount. If you connect the UART but don't power down and power on the MDBT42Q, you won't get a serial port."

b: Yes, you can disable bluetooth NRF.sleep() and NRF.wake(). Note: it disables bluetooth immediately. Even if you are connected via Nordic UART.

c: Edit: ok, Gordon was faster, and he is right about the regulator or not...

[espruino-discuss]

Posted at 2019-12-12 by user106663

Thank you @gfwilliams and @AkosLukacs for your comments.
Very helpful.
Thanks very much