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  • I'd be a little wary of using the F100 - Espruino runs but there isn't a bunch of free space. If you want to do anything useful with the RN2483 then you could do with something bigger.

    I'd check up the LoRa module's power requirements - it could be it's way more than Espruino anyway :)

    Puck.js connects straight to the battery. The uC can run off something like 1.7-3.6v, so it's fine for a CR2032. The chip itself contains its own DC/DC regulator (I just have to fit an inductor/capacitor) so it can do that pretty efficiently as well.

  • I've corrected the post above, the STM32L072xZ has 192 KB Flash, and 20 KB RAM. (Oh, also finally found out that the main difference between the STM32L0 and F0 is: L0 == Cortex M0+ (2-stage pipline), F0 == Cortex M0 (3-stage pipline))

    I'd be a little wary of using the F100 - Espruino runs but there isn't a bunch of free
    space. If you want to do anything useful with the RN2483 then you could do with
    something bigger.

    Thank you for pointing that out! I should probably figure out how Espruino really works before trying to make it work on a new chip... ;) - I've figured that the user program, the JavaScript interpreter, and all the hardware specific peripheral code resides in the flash, and is executed from there. Stack with all the JavaScript variables is in the RAM.... But i really need to learn more, I think there's enough information around on the Espruino page about how you've made all this work. - I can't estimate yet what's possible with 192 KB Flash, and 20 KB RAM...

    (For LoRa applications, it normally just needs to sleep, speak to a sensor and the modem over UART (well, lots of command strings). And store log some values internally... so I think most programs should be fairly small.)

    I'd check up the LoRa module's power requirements - it could be it's
    way more than Espruino anyway :)

    Yes, it's certainly the most power hungry part. According to the RN2483 datasheet (page 7): At 3 V: typical TX supply current: ~15 - 40 mA / RX: ~14 mA / deep sleep: 1.8 uA. So I've figured that it should still be as power efficient as possible, since it only needs to send very rarely, maybe once an hour... and might collect data more often, without the need to wake up the modem.

    (Two colleagues and I work on an open hardware project to be used on the experimental and open thethingsnetwork.org. Still trying to decide whether to use Espruino, MicroPython or something homebrew... Beside the power issues, I'm a fan of Espruino, since people will have an easy time to figure out how to use the device and to work in the IDE is super direct and fun. JavaScript is more widespread, Espruino requires less memory than MicroPython and speed is not really important here...).

    Puck.js connects straight to the battery. The uC can run off something like 1.7-3.6v, so > it's fine for a CR2032. The chip itself contains its own DC/DC regulator (I just have to fit > an inductor/capacitor) so it can do that pretty efficiently as well.

    Oh, that's really interesting! But that's not possible on STM32 micros (?), since they don't include such power management features I think...

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