CrossRoads "Arduino" inspired designs. Need something custom? Contact

8-channel Solid State Relay board

My latest design! Outputs are controlled by silent, non-mechanical Infineon PVT212 "relays", utilizing "International Rectifier’s proprietary HEXFET power MOSFET as the output switch" wired up for 0.25 ohm output resistance to control up to 150V AC/DC and up to 825mA loads. Or, lower capability (and cost) PVT312 with 3 ohm output resistance for 390mA current switching can be used. Outputs controlled by sending data to a '595 shift register, and indicator lights show the active channel(s). Available with male headers, female headers, or screw terminals. Inputs are daisychained to a second set of contacts for easy daisychaining. 

Contact me for pricing, PVT212 vs PVT312 and female vs screw terminals make a big difference. USPS mailing and paypal fee added to all totals.



Youtube videos showing high current (700mA C6060 LED module) being controlled.

32 channel N-MOSFET board.  Designed for 32 1A loads.

The thru hole transistors went obsolete, so the board has been converted to all SMD except for the 74HC595s and the screw terminals. Also added 2A 1206 size diodes from the MOSFET Drain to the supply, it might be enough to eliminate the need for a diode across a low current coil, like a relay, solenoid, or small motor.

Easy to use - just shift in 4 bytes, a 1 turns an output on to sink current. OE/ allows for PWM of all parts together. Easy to daisychain with In and Out headers.

Available completely assembled, $105 plus mailing cost and paypal fee, or

Kit - all SMD parts assembled; ships with four 74HC595, four 16-pin socket, 2 IO headers, 32 load screw terminals, and 4 power source screw terminals, 

$73 plus mailing cost and paypal fee.



New "mini" card types, Mini 2560 & Mini 2561!

We're assembling 2560 cards now, all IO pins broken out. Just add power, or connect a USB Serial adapter 
(FTDI Basic clone shown) and you're on your way. Shipped with headers shown; add IO headers
as you see fit, or contact us for other options. ICSP Header, DTR enable jumper,  FTDI header with 5V enable jumper.
$46 plus shipping & paypal fee.

Mini 2561 will be posted soon, we're waiting on stencil delivery to put one together.

Standalone Programmer!

Ever needed to program some cards in the field but didn't have access to a laptop? Now you don't need one! We collaborated with Nick Gammon and turned his "Upload Hexfile from SD card" into a full-fledged standalone programmer. Connect up a power source (3xAA battery pack, 5VDC wallwart, 7-12VDC wallwart or non-running vehicle power), dial in the program to download and press the Start button.  More details on this page for file naming and re-setting up the card if needed.  

Two display programmer supporting up to 256 files, $50. Contact us to order one. All boards include a Sandisk 4GB SD card and 6 inch/15cm programming cable. Shipping & paypal fee added to all orders.

Programming an Uno under battery power. Select from 1 of 256 files via the rotary encoder:

Mega Screw Shield. 

96 screw terminals to let you securely connect your signals and your shields. Fits all Mega board variants: Mega, MegaADK, Due, Ethermega, Etherdue.
Two pairs of 3.3V/Gnd and six pairs of 5V/Gnd terminals. Board lengthened at the power connector end for additional screw down  holes.  Hole added to access the Due Erase button. Jumpers added to allow separation of  D51-52-53 from the ICSP header. Board size is 130x77mm, overlapping the Mega board edges.

All Screw Shields use Phoenix Contact brand screw terminals, Made in Germany, and very high quality.

$37 each kit. $52 for assembled boards.  Shipping and paypal fee added to all orders.


Here's a shot of a screw shield on an EtherMega with an additional shield added on top, all mounted in a enclosure

Mega Screw Shield options.
One covers all but the double row header, the other covers the double row header. And they can be stacked if you want to.
Assembled price: Larger shield $36, smaller shield $30. USPS shipping & paypal fee additional. Worldwide shipping available.
Double row screw shield
Mega half shield

Uno Screw Shield. Updated for 2016

The board is a little bigger in length now, 77mm across by 73mm, has each header pins brought out to a 3.5mm pitch screw terminal, and to a pin in the 12x20 protoboard area. Extra 3.3V/Gnd screw terminal added along with 4 more 5V/Gnd screw terminals.
The ICSP header will support ICSP connectors from other shields.

Kits are $16.50 each, and ship in a padded envelope. Assembled cards are $21.50 and ship flat rate boxes. Shipping and paypal fee added to all orders.


Don't forget our Book, Arduino for Teens. Published by Cengage Publishing, available from Amazon and other resellers.

Arduino for Teens

ATMega1284P Duemilanova-style 

Board with mostly thru-hole components (USB PTC fuse, 2 voltage regulators). Designed for easy assembly.
Kits less the MIKROE-483 USB module $27. Assembled boards $42.  MIKROE-483 onboard USB Module with USB-B Mini, add $9.  Offboard FTDI Module with USB-B Micro, add $8.  
Shipping and paypal fee added to all orders. Bootloaded Atmega1284P with Blink downloaded: no charge.
 Schematic Layout Assembly  PL for the ATMega1284P Thru PCB 


Atmega1284P On Top (a.k.a. Bobweeny)

Modeled after the Solarbotics Ardweeny, but adapted to have the 1284P on wirewrap socket headers instead of sitting under a board and having to 
solder all the legs to something.  Killed your chip? Pop in a new one!

Header for offboard FTDI Module (can be right angle or vertical), "L" LED at the edge of the board. Cuttable traces for Vcc from FTDI, DTR from FTDI, 
and for the L LED if you don't want a light.

$7.50 extra for an FTDI module - the one I use has a micro USB connector.

Shipping and paypal fee added to all orders.

Schematic & Layout

Jack Christensen's files to add 1284 support to Arduino IDE


Builds on the original Bobuino, makes USB/Serial easier to assemble, adds lots of connection options besides just shields - signal/power/ground available at each pin location. Here it is fully decked with screw terminals and onboard FTDI Module, and with no screw terminals and an offboarrd FTDI module. SD card with 74HC4050 SPI buffering, MAX3232 for RS232 on Serial 2, battery bacled DS1307 with 32.786 KHz crystal.


Assembled board with no FTDI components, no screw terminals:  $69.50
Assembled board with right angle header & FTDI Basic with micro-USB connector, no screw terminals: $76.50
Assembled board with MIKROE483 FTDI module mounted on board with mini-USB connector, no screw terminals: $78
Set of 3.5 pitch screw terminals: Add $5.35
Shipping and paypal fee added to all orders.

(5V regulator is missing in these pic's - they are on order and will be installed)

Schematic in PDF

Schematic in PNG

Core Files for Bobuino '1284P Boards

   replacement Pins_arduino.h to put in Bobuino variant folder
Exciting updates for the Atmega1284P & Arduino - read here.

Pictured: Bobuino 2 with optional screw terminals and optional on-board FTDI module.

Pictured: Bobuino 2 with optional off-board FTDI module and no screw terminals.


ATMega1284P-AU with 32 IO, Dual Hardware UART, 128K FLASH, 16K SRAM.  Schematic, Layout, PL

Kits, $15. Assembled boards with straight male ICSP and FTDI headers $35. Other headers available on request.  Add USPS shipping & paypal fee.


ATMega328P for very small Arduino clones, 1.3" x 1.3". 
Kits, $14. Assembled boards with straight male headers for Bootloading $19 (D11,12,13, Reset, GND, +V). Other headers available on request. Add USPS shipping & paypal fee.  Mini-uino parts

32 P-channel MOSFET board with screw terminals - when you need to Source current vs sink current.

Designed for  1A loads. More pricey than N-channel as the P-MOSFETs and TPIC6C595 shift registers cost  more.  

Easy to use - just shift in 4 bytes, a 1 turns an output on to source current from the NDP6020P . OE/ allows for PWM of all parts together. Easy to daisychain.

Kits available for $76. Assemble available on request, $50.  Shipping and paypal fee added to all orders.


MAX7219 daisychainable breakout board 

Easily connect up 64 LEDs.  Breaks out 2-pins for each LED, connect them up & spread out however you'd like - big display, a globe, etc.  No current limit resistors needed.

Kits for board as pictured with all headers, $13.50 to US addresses, includes padded envelope shipping via USPS & paypal fee. Assembled boards available for $25. Larger quantities will ship in a flat rate box.

I used male-female terminated wires & crimp housings to make this little jumper cable to drive the board with SPI transfers.  shiftOut and other MAX7219 libraries will also work.

Demo of 8 LEDs blinking

Bubblelicious: a nice little 8-digit display controlled by a MAX7219. $12.85 each plus shipping & paypal fee.
The 10uF can be mounted flatter, or on the back. In & Out connectors for daisychaining.
The holes for the display have double rows to accommodate a right angle socket, 2 of mouser 575-2994331211. More application pics & an SPI code example here:

12-digit, or 96 Bit, LED driver.

Uses TPIC6B595 with 150mA continuous sink current per output and SPI to very quickly send 12 bytes to the 

Open Drain shift registers, rated for 150mA continuous, up to 50V.  IN and OUT headers for easy daishchaining.

Tested with LED strings powered from 5V, string anodes connected to +12V. Screw terminal (shown) or barrel jack for power.

Kits $50.  Assembled boards $105. Shipping and paypal fee added to all orders.

Video of two cards with 10 driver chips each controlling a Nike Fuel Band display courtesy of ACSComposites

Schematic  Parts List (PDF)

2014 12 digit driver board

3 boards daisychained. Connect signals from 1st to 2nd to 3rd, add power & Gnd to each.

3 boards

Dual ATMega328P Board

40 IO pins. Headers to connect USB/Serial adapter, ICSP, jumpers to connect MAX232 for Serial.  
Add some jumper wires for chip-to-chip SPI, I2C, or UART-UART comm's.
Bare Boards $5.  Kits, $27. Assembled boards with straight male headers $37. Add USPS shipping & paypal fee.


Dual ATMega1284P Board

64 IO pins. Headers to connect USB/Serial adapter, ICSP, jumpers to connect MAX232 for Serial.  
Add some jumper wires for chip-to-chip SPI, I2C, or UART-UART comm's.
Bare Boards $7.  Kits, $37. Assembled boards with straight male headers $4  7. Add USPS shipping & paypal fee.


Relay boards!

Standalone board controlled by shift register from any Arduino, easy to daisychain, shown pictured with barrel jacks for power.  Uno shield, shift register controlled by any 3 pins. Mega shield, relays driver by D22-D29. Both shown with screw terminals for coil power.
Indicator LEDs for all channels.  Barrel jack or screw terminal options for providing coil power & LED.
Pricier than e-bay modules, easier to use - shift in a 1, relay contacts close.

3-standalone relay cards daisychained  Uno driving 8 strings of LED Christmas lights

The Original Bobuino!

 List of Bobuino Rev17 features.pdf  (opens in new window) Not available except by special arrangement. See Bobuino2 above instead.


Designed to Drive higher voltage (12V) Common Anode 7-Segment Displays using TPIC6B595 and Atmega328P.  

RS232 with buffer & 9-pin connector, SD card socket, connector for 4-channel RF Remote control  from

Swim Pace Display Driver

Examples of Custom Board Designs

'1284 with LiPo charger, Arduino style headers, Xbee socket

12x8 LED Multiplexed Matrix Driver With USB/Serial Adapter

ATMega1284 Test  Board with ICSP & FTDI Headers

Relay Board with '1284, RS232, USB, directly driven relays.

OnTargetMarine, RPN4  Lots of special interfaces!

Similar to Original Bobuino; ATMega1284, RS232 port, FTDI FT232RL USB, SD Card Socket, Screw terminals for 4 serial ports, power, 2 input buttons, 3 switch closures, additional SPI-Dual UART with RS485 interface drivers, 3 additional Status LEDs, Arduino shield compatible.

Fencing Scoring Machine and RF Remote Control  Used at Cross Roads Fencing Center

Smaller Fencing Scoring Machine No time or score

To Robert, Click here

For General Questions, Click here

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