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Member since Nov 2015 • Last active Oct 2016
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  • in General
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    Well I'd hope any espruino would run at much lower power than a cell phone. I guess if I can just add one of those tiny adafruit boards then an on-board lipo charger isn't important. It would be great though if there was an accessible VBatt pin on the board, to power the RTC with a separate backup battery. I actually like the idea of a separate charging board, because of my weird app. I just wasn't sure it was ok to use one.

    For something like the Puck, wireless charging would be awesome. There are Qi charging coils as small as 1 cm diameter that could do the job nicely. That would allow potting the Puck in a solid block of plastic (completely waterproof etc.) that you just drop onto a charger once in a while.

    Gordon, any chance of an ESP3212 shim for the existing Pico? That would be much easier than a whole new board. And does the current wifi shim work with the ESP12? Thanks.

  • in General
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    Thanks! I found the thread about a potential new board and was planning to comment there. I like having the wifi separate from the ARM because of my application niche but for others, the ESP32 will probably change the picture a lot. If you do a new board the (now slowly becoming available) ESP32 looks awfully attractive. Ridiculously powerful, wifi and bluetooth both, and quite cheap (those not familiar, see esp32.net).

    If the ARM and 8266 are both on at once, can I write some protocol for the ARM to ask the 8266 to read and write flash blocks? Speed wouldn't be a huge issue.

    I do think battery backed RTC is essential for most everything I do, so I'm always puzzled why more boards don't have it. Yes I guess I can put the board in an enclosure with a lipo but I liked having it USB powered when in use, and a tiny battery running the RTC when the board is unplugged.

    I do expect to not use the wifi much of the time, at least on battery power, allowing turning off the 8266.

    I have to say I find all the current Espruino hardware (Pico, Wifi, and Puck) really wonderful, tasteful designs. Everything in them is there for a reason and everything missing was omitted because of a sensible trade-off. Kudos!

  • in Projects
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    Here's another watch (BLE and other sensors) that might be of interest:

    http://www.gearbest.com/smart-watches/pp­_236144.html $26.29 + china shipping

    https://www.tindie.com/products/Mixtile/­mixtile-gena/ $34.00 free shipping in USA

    http://www.mixtile.com/topic/721601/mixt­ile-gena/ more info

    27.6x40.2x9.1mm, includes LCD display, 8MB ram, 16MB rom,
    Javascript API, MT6260 (ARM7EJ) + nRF51822 processors
    buttons on sides of module, micro usb socket, lipo battery
    apparently includes ios integration, but lousy docs for devs.

    These things are apparently common and available from a lot of vendors.

  • in General
    Avatar for user58984

    Hi, I just saw the espruino wifi and it looks like a fantastic product! A couple questions:

    1) the Tindie page mentions an RTC with external oscillator. What does that mean? Is there an xtal oscillator on the board that's independent of the main chip? Are there pins for battery-backup of the RTC when the main power isn't available?

    2) If I could wish for one more feature, it would be a lipo charger on the board. Absent that, is there a simple add-on that I can put between a lipo battery and the board, that allows running from either USB power o r battery, and charges the battery from USB? Something like the Adafruit Feather series.

    3) [added] How does the STM processor communicate with the 8266? Is that an ESP12 module with the 4MB SPI flash on it? It would be nice to be able to use that flash.



    P.S. I think it is ok to make the board a little bigger, to support these features! Once it's no longer in the usb plug-in form factor, a few more square mm doesn't matter as much. It's still smaller than the Teensy and comparable boards. Here's another one that I really like:


    It has a supercap to power its RTC, an interesting idea. No wifi though. Could use a separate module for that.

  • in Electronics
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    Will there likely be a follow-on to the Pico at some point?

  • in General
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    Thanks! It's a voice codec so sampling would be 8khz probably. I'm good at C under Linux though I haven't done any serious embedded C yet. I hope I can deal with it. Yes I'm a big fan of scripting languages because of their interactivity and memory safety compared to C. I had been mostly wondering about the differences between them (JS, Lua, uPy, etc). I'll look at the Espruino JS internals docs! The Pico is the nicest of these boards that I've seen so far (small size is an issue) and I've looked at quite a few. Even if I write the whole application in C, I probably want to use the board as I'm not a hardware guy.

  • in General
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    Thanks! I had no idea the Digispark used so much power. I wonder what's going on with that. I'd been thinking of using a tiny Arduino-inspired board for some things (Atmega 328 based) and wonder if it has the same issue.

    My application does need an accurate (xtal) RTC, so it's good that it's doable. It would be great if a version was available with the xtal already on it.

    I also need to do some realtime processing (audio signals) in the app--is it reasonable to do that on the Espruino? I can stand a few msec of delay in the system so the JS either needs to be relatively pause-free with the output clocked out on a timer tick, or the realtime stuff could be in a separate task if there's some kind of RTOS. The realtime stuff would probably be written in C either way, or at least call some C code.

    Separate issue/question: I don't know if this is the right place to ask, but why Javascript? I.e. I wonder what the tradeoffs are between JS, MicroPython, eLua, or various Lisp-ish dialects, all of which could run on this class of hardware.

  • in General
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    Hi, I saw the Pico on Adafruit recently and it looks great! A few questions that I couldn't figure out from the blurbs and this board so far:

    1) Does the Pico have an RTC that can be accessed through JS? What is the power drain to keep the RTC running and a small amount of ram retention (not necessarily the whole space)? Is there some capacitance on the board (or is it reasonable to add some), to keep the RTC alive through a battery swap?

    2) If I don't need USB plug, is it possible to cut off the connector without messing up the board function, to make the board smaller? The Digispark is made to allow this, I've heard, but it's a much less powerful board.