If you’ve watched the forum, it’s been suggested to develop a new Moteino board featuring new/more powerful/more flexible or even ARM microcontrollers. Mentioned candidates were the Atmega328PB, STM32, SAMD from Microchip and perhaps others were mentioned over time as well.
Say hello to MoteinoM0 – it features the popular SAMD21G ARM Cortex M0+ 32bit processor (48Mhz, 256kb FLASH, 32kb SRAM). It’s quite an awesome bit of silicon brains and after months of playing with it, tweaking libraries and sketches, testing peripherals and designing add-ons for it, and developing an Arduino package for it that is oriented on LowPowerLab‘s most important points of interest, it is now available to the public.
But SAMD21 has been offered by others for years you say. How is this exciting and why did this take so long? I didn’t want to spam the market with a new clone and claim this is the best thing since Arduino Zero. Here are a few highlights that I think will make MoteinoM0 different and interesting:
- long range wireless programming enabled just like all the other current AVR Moteinos!
- Got low power? You bet! How about 6µA in standby sleep? MoteinoM0 yields the real low power mode achievable by the SAMD21, 7µA in watchdog periodic sleep, +1µA for the external 4MBIT FLASH-MEM chip and radio module
- supports RFM69HCW and LoRa radios, plus secondary radios and add-ons, see below
- a modular design enables compact platform for I2C/SPI/GPIO add-ons, just a few examples to mention:
- SD-card logger ( with “zero” power control)
- weather node
- multi DOF accelerometer/gyroscope/magnetometer
- secondary RFM transceiver (say you want an FSK and LoRa Gateway to listen concurrently or combine different concurrent frequencies)
- break out as many useful and Arduino supported pins as possible in a symmetric and compact board layout
- ease of side castellated mounts allow these add-ons to be mounted directly flat on the PCB without additional headers, here’s a simple weather-node add-on board that only requires one sided soldering and can be easily removed and reused:
- you may also stack above/below using extra headers or solder extension wiring to the side half-holes for quick removal and re-use later:
Here is a quick pin reference and schematic:
A few things about similarity to the standard Arduino Zero:
- this board was designed to be as compatible with Arduino Zero as possible in terms of available MCU functionality
- GPIO and core package is adapted from Arduino Zero, all GPIO is accessible the same way, except PA28 (USB_HOST_EN) which is not connected
- as seen in the reference above, some pins are hardwired to the radio transceiver and SPIFlash (A2/SS for radio, D8 for FLASH-MEM) and used by these modules
- you should be able to use most Arduino examples with MoteinM0 without a lot of hassle. If you’re already familiar with Arduino Zero this board should feel right at home
Read below for why this took “so long”.
From popular demand, there is now a Moteino 8Mhz variant which has the following differences to the regular Moteino:
- no LDO linear regulator
- the VIN and 3v3 pins are connected via a 0ohm resistor (including FTDI header VIN)
- must be powered from 3.6v or less when RFM radio and/or FLASH-MEM are installed onboard, otherwise without radio/external flash the board will work up to 5V
- 16mhz resonator is still installed but not used with the 8Mhz fuses. This means you can still change the fuses yourself and use it if you’d like, but this will only be safe down to about 3V
- The fuses are: LOW: 0xD2, HI: 0xDC, EXTENDED: 0xFE
- even more ultra low power – 2uA less current than the regular Moteino
- Runs DualOptiboot compiled for 8mhz
- 57600baud upload programming speed (vs. 115200)
- you will need to install the latest Moteino definition (v1.3 or newer) in your Arduino IDE Board Manager to gain the new Moteino (8Mhz) target board:
For the latest updates and specs on this board, always check the official Moteino guide.
To program this Moteino the FTDI-Adapter offered in the shop can be modified to pass a safe 3.3V to the 8Mhz LDO-less Moteino – cut the *5V Output Voltage jumper and solder the 3.3V one:
Note that this mod will make the FTDI-Adapter regulate power, but it can only supply about 50mA to the Moteino, if you draw more power, the adapter might drop and reconnect to your computer
Alternatively, you can build a dedicated adapter that takes the 5V from the USB and regulates it to 3.3v, here’s such an example which uses the LDO from the Moteino itself (MCP1703) along with a 1uF and 0.1uF caps, all other connections are passed through and assumed to be 3.3v levels:
You would then use it in between your stock unmodified FTDI-Adapter (or equivalent board, providing 5V VIN power and 3.3V TX/RX/DTR signals), and the no-LDO Moteino which requires 3.3V when radio/flash are present:
These types of Moteinos are ideal for ultra low power coin cell and other micro power powered nodes – power them from 3.6V or less. Of course, when you have such tiny power supplies, you must choose your transceiver carefully, as you likely cannot transmit at full 20dBm power from a tiny coincell. The W/CW 13dBm radios running the auto-power-dial RFM69_ATC library extension would be recommended for running on coin cells or small solar cells.
I can’t wait to see what you guys will make with these!
After Moteino R4 has been the long running champion of its lineup, and R5 has had a brief period of glory, Moteino has now been shipping for the past week at revision R6!
Wait, what happened to R5 which was never announced you ask?
Well R5 was mainly a transceiver layout change from R4, it also added a u.FL RF connector (which is now offered in the shop) and SMA connector “helper” pads, and few other minor layout changes, nothing too significant and otherwise identical to R4. Customers were now getting HCW and LoRa radios on the same Moteino PCB instead of separate PCBs for HW and LoRa.
However in R6 there are more important changes:
- CW transceiver layout has been added in addition to the RFM69/LoRa layout, which means that the whole spectrum of RFM69 and LoRa radios are supported. Note that W and HW, while still in the shop, are no longer available as an option for MoteinoR6 – they are replaced by CW and HCW (which are 100% equivalent from a software and features perspective, but smaller!)
- supported transceivers: RFM69CW, RFM69HCW, RFM95/96/LoRa
- in addition to this, RFM12B is now also usable (though not sold) with Moteino R6 because of the new CW pads. Note that the RFM12B library is still usable but no longer actively developed or supported
- a delay cap was added to DTR to avoid situations where the Moteino never wakes from an ultra low power state – this has been mentioned and discussed in the forum
- u.FL pads kept for those who want to connect a pigtail instead of straight coax or the provided monopole wire antenna
- the Trace Antenna variant reflects all these changes as well except it’s connected to the onboard PCB antenna and does not require an external antenna
Here are RF connector options now possible on the Moteino, all these RF connectors are available in the shop for convenience:
Quite excited to announce the new PIR sensor option on SwitchMote, this was requested by a user and is finally available in the shop. The chosen PIR sensor was the ultra low power Panasonic EKMB1201111 (same as offered in the MotionMote Kit). It’s a fantastic sensor, very small fully contained package, the only down side is these sensors are expensive. For this reason the kit is now significantly discounted for a limited time! You may source your own PIR of course (and mention you want the PIR parts at checkout), a forum user reported the older revision of these sensors might be found for cheap on eBay.
The SwitchMote Guide was updated with instructions for this change. Mainly the kit will come with 2 buttons and the PIR instead of 3 buttons, along with a required 10K pullup and the front cover matching the PIR sensor. Here is the updated kit content, notice the front PCB is different:
UPDATE: A sample RFM69 sketch for WeatherShield R2 is posted here.
WeatherShield is now at R2 and although the PCB is very similar to R1 there are some significant differences. The R1 used to have a BMP180 until Bosch decided to stop making it. So R2 came about partly because of that reason, and is now shipped with a BME280 which includes all Temperature/Humidity/Pressure readings all in 1 sensor. This sensor is pretty popular it seems so hopefully the supply will be plenty for a long time.
Here’s a look at R2:
And the schematic:
Notice a few changes:
- The voltage monitor circuit is now without a mosfet – this was removed and a resistor was added (the angled resistor) to tie the circuit permanently to A7. The old pads are still there so including the mosfet as on R1 is an option if someone really wants it.
- there is now a solder jumper to allow disconnecting the battery monitor from A7
- The Si7021 pads are still there if you’d like to add that sensor yourself
The board will idle at around 3.5uA when the sensor is put to sleep because of the voltage monitor. That’s still very low power but if you want 100nA instead and don’t care for battery monitoring, cut the jumper to A7. Bring your feedback in the forums!
The MotionMote is now available with optional BME280 sensors and Panasonic PIR ultra low power sensors (the EKMB1201111: 5m 2uA, white). When you opt for the Panasonic PIR you get that instead of the chinese HC-SR501 with the appropriate enclosure front cover and required acrylic standoff. The guide explains how to use the standoff and switch the PIR input voltage from battery to regulated 3.3v from the Moteino:
The MotionMote sample sketch was updated to include BME280 code support, but it’s commented out (will require a 3rd party library to read the sensor). If you get the BME280, make sure to uncomment the BME280 related code lines.
Although expensive, this PIR allows running on less than 10uA of idle current draw. Who thought that less power costs more huh! When assembled these will look like this:
The OLED variant of the kit might be available soon as well, I will update the product page with that option when/if it does. That allows using this kit as a battery operated Moteino with a nifty OLED display for any general purpose use on your wireless IoT network. Here is that at a glance next to the regular HC-SR501 PIR based MotionMote.
I would like to introduce the new MotionMote R3 revision. The kit will be mostly the same, with the exception that it supports some exciting new options. Read on for details.
I had previously released a MoteinoMEGA with trace antenna, and there is now a regular Moteino with trace antenna. Everything is the same as the MEGA variant, except of course this is the atmega328p based Moteino, the most popular variant. The antenna is tuned to work in the 868-915 bands and should deliver very decent performance, close to the wire monopole. Here it is next to it’s MEGA sister board:
A new revision of MightyHat has started to ship out. Most everything is the same. Here is a rundown of the most significant changes:
- the slide switch that cuts off the battery is replaced with a more robust hooded switch that also has a longer slider which can reach out of a 1/8″ thick acrylic case
- The RST pin of the LCD is now connected to the RST of the atmega328, (previously wired to A1). This saves the A1 pin and resets the LCD whenever the atmega is reset. This is the only change posted in the RFM69 MightyHat sample sketch and I added a directive setting to make it easy to switch between R2 and R3.
- enlarged the slot in front of the battery connector for easier wrapping of the battery wiring
- added a capacitor footprint on the 5V* output rail. This makes it easier to add more capacitance to the boosted voltage when needed.
- other various cosmetic and silkscreen adjustments
Over the past few months a friend has helped me create a MoteinoMEGA variant with a trace antenna tuned for between 768Mhz to 1.16GHz. So this should be great for 868-915mhz. I’ve tested this variant myself (915mhz) and I was surprised how well it performs compared to a wire monopole (which will still be better given the type of antenna). I did not do extensive testing but I am pretty confident this turned out as a great antenna and I am offering the remainder of this batch for those eager to have one and perhaps do more testing on their own. Depending on the response I may or may not ever make more of these, we shall see. The same antenna could be used with any other Moteino but I want to see the response of the users before I invest too much capital in new batches of Moteinos. The ANT pad and u.FL footprint are still there if for some reason the user wants to cut off the trace antenna and use one of those instead with a monopole or different antenna. Otherwise everything else is the same, well, except the yellow soldermask which has a nice orange hue from my new PCB supplier. I will offer these with RFM69W/HW in 868/915mhz or without a transceiver, your choice. Enjoy.