UPDATE: Eagle schematic and layout are in their github repo.
There is now also a Moteino-USB version which includes the FTDI adapter and the Moteino all in one at a combined lower price.

Some people have been asking for FTDI adapters for programming Moteinos to avoid having to buy them from another store and hence pay shipping/handling twice. So I created one. It’s actually based on the Adafruit FTDI-friend which was a very good design. Here are the features:

• 5V power level (default) – adjustable to 3V
• 3V logic level (default) – adjustable to 5V
• pin 6 is RTS (default) – adjustable to DTR
• RX/TX LEDs
• The pinout is standard [ GND – CTS – VCC – TX – RX – RTS ] and will work with any Arduino clone that has this as a programming interface.
• compact layout

The underside of the board contains some jumpers that are shorted for the default settings mentioned above (5V power level, 3V logic level, pin6 = RTS) – these are standard settings that come with the FTDI cables and should work in most instances. Hackers may want to switch these settings – for this the default shorts need to be cut with a razor blade and the other jumper needs to be shorted by soldering the jumper pads together.

I’m working on sourcing some USB cables to go with these soon. Here are more images and the schematic:

I’ve been working on a Atmega32u4 version of Moteino, one that would allow USB connectivity and inherently no need for a FTDI adapter. This is basically an Arduino Leonardo clone that adds the RFM12B radio and a SPI FLASH footprint for optional data logging ability. I meant to post the details of this for several weeks but never found the time for a write-up.

I now have a working prototype. I have some small changes in mind but it is functional as is. For this version I had to make a small change to the Caterina bootloader to make the onboard LED work properly. By default the Caterina bootloader assumes the LED is sinking current from VDD to the output pin, my version was sinking current from the output pin to GND. This is one of my planned changes, to allow the default Caterina to work with MoteinoLeo out of the box. Wireless programming will not yet work on Moteino Leo and I don’t know when I will find the time to customize Caterina for this purpose. From all I know Caterina takes about ~4kb of bootloader space which might be too much to add ~500 bytes of extra code. I will have to experiment with this sometime in the future if people actually have an interest in this.

Fun fact: using the same DIY metal stencil technique I was able to make a stencil, apply the paste with it and make this Moteino Leo prototype.

Eagle files and bootloader source are published in GitHub.

Here’s a quick review of some PCBs I ordered from ITead Studio.
While some of the cosmetics of these PCBs are not top quality, electrically they appear to be OK. I assembled several dozen of these from this batch and all the Moteinos passed programming and testing.

The other day I found my TI-83 Plus calculator which I used in college and I hadn’t powered up for years, so I put some batteries in and turned it on. Did I see black smoke? No…instead the screen was all garbled up with all kinds of junk, sometimes it would only have a horizontal line, or take a lot of button pressing to get it to even show anything on the screen. Turns out it was a perfectly good calculator, brought back to life with a simple 10 minute soldering job. Continue reading →