Using radio

[espruino-discuss2]

Posted at 2022-07-22 by user147266

Hi, I have this old car key that I presume works with radio and wondered if I could get my Bangle.js to receive signals from it?

[espruino-discuss2]

Posted at 2022-07-23 by @fanoush

There are many types of radios that differ both in frequencies and protocols. BLE radio in Bangle can do only 2.4GHz and the hardware can send only limited types of packets for similar protocols, you can't do e.g. wi-fi over it even if it is 2.4GHz too. Nordic SDK says "Supported protocols - The nRF52 Series multiprotocol radio supports Bluetooth Low Energy, proprietary (including Enhanced ShockBurst and Gazell), ANT, Thread, Zigbee, and 802.15. 4.".

Your old car key may quite likely use different frequency like 433/868/915 MHz. If it uses 2.4GHz then there is some chance the hardware could do it but it would be a lot of work to figure out details.

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Posted at 2022-07-23 by @fanoush

BTW it is possible to very easily figure out at least the frequency of the remote by using cheap DVB-T usb dongle (google RTL2832U DVB-T or RTL-SDR) and software like Universal Radio Hacker https://github.com/jopohl/urh

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Posted at 2022-07-23 by Hank

Is there an example of a zigbee implementation available? Just curious...

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Posted at 2022-07-24 by @fanoush

easiest may be using the https://www.nordicsemi.com/Products/Development-software/nrf5-sdk-for-thread-and-zigbee which is based on nrf5 sdk 16 so building espruino with it may not be hard see also https://infocenter.nordicsemi.com/index.jsp?topic=%2Fstruct_sdk%2Fstruct%2Fsdk_thread_zigbee_latest.html

Another option is nRF Connect SDK which is based on Zephyr - very different to older Nordic SDK
https://www.nordicsemi.com/products/zigbee