MoteinoLeo: new LowPowerLab family member


Update: MoteinoLeo is now discontinued and no longer available for sale.


The difference between MoteinoLeo and the regularĀ Moteino is pretty obvious – it’s got built in USB. It’s conceptually an Arduino Leonardo clone, with an RFM12B transceiver solderable on the bottom, with a few minor changes and some added features. It runs at 16Mhz, 3.3v, has an optional FLASH footprint for data logging (wireless programming on Leo is not yet achieved, perhaps in the future if a custom bootloader will permit). There’s also a 750mA PTC fuse to protect the USB against shorts or over current.

Design files are on the MoteinoLeo Github repository.

Here’s a pinout diagram:


Compared to Moteino:




9 thoughts on “MoteinoLeo: new LowPowerLab family member

  1. Is is possible to use I2C and SPI simultaneously? (The radio on the moteino leo is using SPI, correct?)

    I’d like to use my I2C 128×32 OLED display from adafruit with the moteino LEO, but I’m not sure how to wire it seeing as how the moteino leo already has the radio wired up as SPI…

    Thanks for any advice… Eric

    • The common signal between the RFM12B and I2C is the SCL (D3/INT0), unfortunately all interrupt pins on the atmega32u4 are on important pins so INT0 was chosen to work with RFM12B for compatibility reasons. So to use I2C you would have to write a little code/function that would switch to “I2C mode” when you need to update your LCD. It would have to disable interrupts noInterrupts() to stop the RFM12B interrupt handler, set D3 as output for the I2C clock: pinMode(3, OUTPUT), do the LCD work, then when done with LCD: pinMode(3, INPUT), enable interrupts: interrupts(). Electrically I don’t believe anything else is needed.

      • Well, I finally got around to trying this method, but with no success. Would it be more logical to use an SPI enabled display (or even feasible)?

        • I haven’t used an I2C display, but there are also serial and also SPI displays like you suggested. Also the barebones ones (parallel). I guess it’s hard to say without trying. The transceivers and FLASH chips use SPI, so there’s already 2 SPI devices, adding another one should not be a problem.

  2. Beatiful product, all i need: atmel+rfm+soic memory!!!
    but i want to ask:
    1) i am really very constrained by the board size (and i think you too) so what you didn’t used a 0.05″ aproach like fabio varessano femtoduino?
    2) why don’t use a more powerfull rfm22b module, are your rfm12 library compatible?

    • I didn’t go that route because 99% of the users will not be that constrained, and to make the board useful I wanted the standard 0.1″ spacing so anyone could just plug it into a breadboard if they need to, instead of having to solder wires or have some kind of breakout for it to bring those tiny connections to a more 0.1″ useful spacing. Also the 0.05″ spaced headers are more expensive.
      I have used RFM22 but opted to use the new RFM69 instead (only on Moteino R3 as we speak). However Leo is only available with RFM12B at the moment.

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