Project board for Arduino

This board provides pads for the most popular surface mount packages, broken out to rows of 0.1" pin header for ease of connection. Each pin goes to two or three holes, so making multiple connections to a pin is no problem. At the top, a row of 8 pads that can take either an SOT-23-6 part (such as the MAX1555 LiPo charger IC, or some small EEPROMs), or the 5050 package commonly used for RGB-LEDs, including the WS2812/B. On the back of the board, these pins go to pads for three SOIC-16 packages (you can put two SOIC-8's next to each other too). To the right of that are two banks of pads for SOT-23 MOSFETs. Each bank of 4 fets is connected to a common source, and pads are provided for a resistor between source and gate. A barrel jack, and optionally voltage regulators (in SOT-223 and SOIC-23-5 package) can be added to supply power.

Now shipping Rev. B with MSOP-12 (0.5mm pitch)/WSON-12 outline on the opposite side of the board from the MSOP-12 (0.65mm).

The popular ESP8266 wifi module can be easily used with the pads in the lower right corner. These are for the Wi7-7 and Wi7-12 package, (from Electrodragon and others), and pads are provided for a capacitor across the power supply, since these seem to need it (Of course, you can use the Wi7C-1 with the 8 pins in the through-hole prototyping area). These same pads are the same spacing as used in the HopeRF RF transceiver modules and many others. The spacing is also the same as used in 1W RGB/RGBW LEDs. While the LED would rapidly overheat at full power, this might be useful at a lower duty cycle, or for brief flashes. In this case, the SOT-89 pads on the underside can be used for AMC7135 current regulators for the LEDs.

If you aren't using the SMD pads, the through-holes connected to them can be used as normal prototyping area. Alternately, the large space can be used to mount additional modules - for an example of this, see the third product picture, showing a prototype I made where most of the space was taken up with modules, and only the SOT-23 outlines are used for SMD parts

Four ways to mount an MCU

• Arduino Pro Mini (either original, or the one with the A4-A7 pins near the end) or Nano using pin header.
• Arduino Pro Mini soldered directly onto board, as shown above
• ATmega328p, 1284p or other MCU in dip package in through-hole area
• ATTiny or other SOIC or TSSOP microcontroller in appropriate SMD area

Features

• Row of 8 SOT-23-6/5050 pads on front, 3 SOIC16 pads on back
• Two sets of pads for 4 SOT-23 MOSFET w/pads for resistor between gate and source
• Two rows of 8 pins in 0.1", 2mm, and 0.05" pitch
• Set of 2 SOIC24W/N and one MSOP-12 (0.65mm) DFN-12 pads on front, 2 SSOP-28 and 1 WSON-12/MSOP-12 (0.5mm) on back
• Multiple smaller SOIC or SSOP parts can be placed in one of the larger footprints.
• Four wire signal bus runs the length of SOIC24/DFN/SSOP area - ideal for working with multiple I2C or SPI devices
• Pads to mount a barrel power jack (center positive), input capacitors
• Pads for three voltage regulators in standard pinouts (two TO-223, one SOT-23-5) and caps
• Exposed GND and Vcc traces for easy power and ground wiring
• Pads for ESP-8266 (castellated pad version) + supply capacitor.
• ESP-8266 pads can also be used for HopeRF products, or high power LEDs (with limited duty cycle)
• Pads for four SOT-89 devices, behind ESP8266
• Six mounting holes, five of which connected to ground
• Ample traditional through-hole prototyping space