Introducing the no-LDO 8Mhz Moteino

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!

Moteino R6 released

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:


SwitchMote PIR motion sensor option

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:

WeatherShield R2 released

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: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!

MotionMote R3 with BME280 & Panasonic PIRs

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.

Moteino with trace antenna

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:

MightyHat R3

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

MoteinoMEGA with trace antenna

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.

MightyHat R2

Revision R2 of MightyHat is now available. Since the changes are not very significant I debated whether this should be really a R1.1 but I don’t like minor revision numbers so I went with R2. Basically it just adds the following main features:

  • Battery power switch – this is a slide switch that can cutoff the battery. During my many hours of testing, it occurred it would be useful to just have an onboard battery switch instead of pulling it in and out. Also if you have the battery tucked tight underneath the board it’s not always really easy to pull the JST connector. Or say if you want to ship a complete Pi+MightyHat+Battery inside an enclosure and don’t want to have it powered up. A side switch is convenient for this purpose:
    If you don’t want the switch then there is a solder jumper behind it which you will need to solder-bridge if you are using a backup battery.
  • Two momentary tactile buttons tied to the remaining available I2C pins which were previously unused (A4 and A5). These will be general purpose buttons to do whatever you like. If you want you can build some menu interaction for the LCD or whatever else. They connect GND to A4 and A5 and the pins should be declared as INPUT_PULLUP. The provided kit buttons have long actuators that rise just above the main power button (to allow pressing them when enclosed), but you could otherwise solder any standard 6mm tactile buttons here.
  • A few power path optimizations and tweaks.
  • I sourced RP-SMA connectors which seem to be a lot more popular than SMA (shown in photo below – note male pin in the center).
  • Besides the new positions/cutouts of the buttons and switch all other physical features remain at the same positions as R1.

I have an enclosure close to finalizing so maybe I will post that when it’s ready for those who’d like to lasercut their own case. I played around with 1/8″ and 1/16″ acrylic and finally settled on 1/8″ because it’s more dimensionally stable and makes for a sturdier case. The thin 1/16″ was light but it was prone to breaking where holes were very close to the edge or between USB/Ethernet connectors. Here are a few snapshots of R2:

Wondering what it takes to put together a kit with all the necessary parts to make a completely functional piece of hardware like this? Consider these facts:

  • The PCB board has some 62 SMD parts on it after picking and placing.
  • Some 13 more through hole parts (and the SMD transceiver) are required to be sourced and soldered separately (some optional like the LCD, buzzer or SMA connector).
  • To make a nice tight fit while avoiding any shorts or touching ontop of the Pi, an optimal height of 17mm is required between the Pi and MightyHat. Standoff combinations were sourced to achieve this height since 17mm is not standard or easy to find stanoff height.
  • Add a  1-cell 3.7v Lithium Polymer battery (optional) to act as a UPS and you are golden. I recommend this 2Ah battery from Adafruit which has decent capacity and attaches nicely with velcro under the Hat.
  • Total height of the Pi+MightyHat with all options installed is just 32mm (about 40mm when enclosed with 1/8″/3mm acrylic).

Finally I need to mention I have made numerous tweaks and improvements to the RFM69 gateway sample sketch for the MightyHat. I added a bunch of defines that make it easy to disable the LCD, wireless programming, or Automatic Transmission Control. Besides making the sketch a lot smaller (LCD has the largest footprint because of fonts and graphics), it allows  running your gateway without an LCD: