Ethernet Arduinos (and Compatibles)

Also on the spreadsheet, three boards with built-in ethernet:

• There's finally an official Arduino Ethernet ($60), complete with RJ45 port. It has an FTDI cable header for programming (no USB), a microSD card slot for storage, and there's an optional PoE daughter card.
• SparkFun also released an Arduino-compatible board with ethernet, the Ethernet Pro ($55), but without the SD card slot. It's less cluttered than the official board, hopefully the price will come down as more people build projects around them.
• Additionally, the Freetronics EtherTen ($70) includes a microSD slot and (mini) USB interface.

All of these are compatible with an Arduino (or Arduino-compatible) board with the ethernet shield ($40) on top, but I wonder: will shields fit on any of these without hitting the magjack? Or do they use taller female pin sockets? They're also equivalent to an Arduino hooked up to a Wiznet W5100, eg. with a WIZ811MJ module ($20!). Too bad Adafruit doesn't sell the ethernet module breakout shield anymore, but at least the design files are still available.

Call me cheap, but these all seem overpriced, being based around a $4 microcontroller! With a basic Arduino board at $20 and WIZ811MJ module at $20, why isn't the SparkFun Ethernet Pro $40 or $45?

More 'duinos on the Spreadsheet

I've continued to add Arduino-compatible boards to the spreadsheet, bringing the count to 119 boards. You can get there easily by remembering "allarduinos" and going to http://tinyurl.com/allarduinos or http://bit.ly/allarduinos.

Some recent additions to the spreadsheet:

• Three (!) clock boards from Wise Time With Arduino:
  • Wise Clock 3 with a 32x16 Red-Green LED display (from Sure Electronics) has many different modes, including Pac Man, game of life, Pong, and... make your own!
    
  • ClockTHREE Junior (aka C3Jr), a collaboration with WyoLum, which is similar to the QlockTWO readable clock.
  • DWex, "Duino Watch for experimenters"-- chock full of SMD LED goodness; this actually came out last year but I missed it.
• From SparkFun comes the PTH (plated through-hole) Kit, very similar to Diavolino and my Minimalduino, but surprisingly priced at $30. It doesn't seem up to SparkFun's high standards though, since there is no power switch and the electrolytic capacitors are too tall, so shields won't fit.

Minimal Arduino?

I prefer breadboard-friendly Arduino-compatible boards like Boarduino and iDuino, but I keep wanting functionality people have built into shields like Adafruit's Motor Shield and Batsocks' TellyMate Shield.

All I want in an Arduino:

• ATmega328
• FTDI programming header
• Arduino "form factor" with odd D7/D8 spacing and standoff holes

Sorting my Arduino-compatible board spreadsheet first by price, then by form factor, it seems the lowest price for a shield-compatible board is ~$17 for a serial Freeduino, compared to ~$10 for a Dorkboard, though the latter comes with an ATmega168, not a 328.

Necessary items:

• microcontroller: ATmega328, socket, capacitor
• clock: oscillator and 2 caps, or a resonator
• reset: 90-degree (side) button, 10K resistor
• FTDI cable interface: 6-pin header, capacitor
• Power: Barrel connector, 2-pin header

Extra interface header pin pads:

• icsp (2x3)
• i2c (4)
• spi (6) (nah)

Simple extras, parts not provided:

• Power indicator: LED, 1K resistor
• TX/RX indicators: 2 more LEDs, 2 more 1K resistors
• Power regulation: 7805, 2 capacitors, jumper
• Diode to prevent inverted power hookup

I'm traveling for the next month so this will be a fun little layout project, perhaps as a way to learn kicad (as opposed to EAGLE, which I currently use) and to explore board house pricing and specs. The goal is to be able to produce a $10 kit (cost), which may be possible given how many goodies SparkFun includes in their $20 Arduino Pro 328.

Update 12/29: I got a single-sided board laid out with just four jumpers, and I'll tear it up and redo it with the programming header where I want it, jumping TX and RX across the board. The files for the "Severino" single-sided board helped me figure out the routing.