SparkFun: ROB-10267

Description: The EasyDriver is a simple to use stepper motor driver, compatible with anything that can output a digital 0 to 5V pulse (or 0 to 3.3V pulse if you solder SJ2 closed on the EasyDriver). EasyDriver requires a 7V to 20V supply to power the motor and can power any voltage of stepper motor. The EasyDriver has an on board voltage regulator for the digital interface that can be set to 5V or 3.3V. Connect a 4-wire stepper motor and a microcontroller and you’ve got precision motor control! EasyDriver drives bi-polar motors, and motors wired as bi-polar. I.e. 4,6, or 8 wire stepper motors. On this version (v4.4) we fixed the silk error on the min/max adjustment.

This is the newest version of EasyDriver V4 co-designed with Brian Schmalz. It provides much more flexibility and control over your stepper motor, when compared to older versions. The microstep select (MS1 and MS2) pins of the A3967 are broken out allowing adjustments to the microstepping resolution. The sleep and enable pins are also broken out for further control.

Note: Do not connect or disconnect a motor while the driver is energized. This will cause permanent damage to the A3967 IC.

Note: This product is a collaboration with Brian Schmalz. A portion of each sales goes back to them for product support and continued development.

Features:

• A3967 microstepping driver
• MS1 and MS2 pins broken out to change microstepping resolution to full, half, quarter and eighth steps (defaults to eighth)
• Compatible with 4, 6, and 8 wire stepper motors of any voltage
• Adjustable current control from 150mA/phase to 750mA/phase
• Power supply range from 7V to 20V. The higher the voltage, the higher the torque at high speeds

Don Luc

SparkFun: DEV-09530

Description: The SparkFun OpenLog is an open source data logger. Simple to use, simple to change. We wanted to create a serial logger that just worked. Power up this device and it will start logging any received serial data at 9600bps. Sending Ctrl+z three times will drop out of logging and in to command mode. ‘new’ will create a new file. ‘md’ makes a directory. ‘?’ brings up the list of commands. OpenLog doesn’t do a lot, but it does log serial streams extremely well.

Example:

 >new testfile.txt  
 >append testfile.txt  
 <(send large amounts of text followed by three ctrl+z characters)

That’s really it! OpenLog firmware is open source and is based on Bill Greiman’s sdfatlib. OpenLog currently supports FAT16 and FAT32 microSD cards (we’ve tested up to 64GB!).

All the design files (schematic, PCB layout, firmware) are open source released under the CC-SA v3 license and are available through GitHub.

Note: New firmware is available which allows the OpenLog to be used in Arduino 1.0 and also allows for higher baud rates. Check the links below for more information.

Features:

• Log to low-cost microSD FAT16/32 cards up to 16GB
• Simple command interface
• Edit config.txt file from a computer to change baud rate and other system settings
• Three modes:
  NewLog creates a new log every power up and immediately starts logging
  SeqLog appends a file called “SeqLog.txt” at every power up and immediately starts logging
  Command mode starts OpenLog at a command prompt at power up
• Configurable baud rates (2400 to 115200bps)
• Configure unit through config file or the menu system
• Power, ground, and RX-I are the minimum connections
• Reprogrammable ATmega328 using the Arduino IDE
• Two LEDs indicate writing status
• Input voltage from 3.3V to 12V
• 2mA idle, 6mA at maximum recording rate

Dimensions: 0.16 x 0.6 x 0.75″ (4 x 15 x 19mm)

Don Luc

SparkFun: BOB-09056

Description: This is a breakout board for the very handy 16-Channel Analog/Digital Multiplexer/Demultiplexer CD74HC4067. This chip is like a rotary switch – it internally routes the common pin (COM in the schematic, SIG on the board) to one of 16 channel pins (CHANxx). It works with both digital and analog signals (the voltage can’t be higher than VCC), and the connections function in either direction. To control it, connect 4 digital outputs to the chip’s address select pins (S0-S3), and send it the binary address of the channel you want (see the datasheet for details). This allows you to connect up to 16 sensors to your system using only 5 pins!

Since the mux/demux also works with digital signals, you can use it to pipe TTL-level serial data to or from multiple devices. For example, you could use it to connect the TX pins of 16 devices to one RX pin on your microcontroller. You can then select any one of those 16 devices to listen to. If you want two-way communications, you can add a second board to route your microcontroller’s TX line to 16 device’s RX lines. By using multiple boards, you can create similar arrangements for I2C, SPI, etc.

The internal switches are bidirectional, support voltages between ground and VCC, have low “on” resistance and low “off” leakage, and to prevent crosstalk, perform “break-before-make” switching. The board also breaks out the chip’s “enable” pin, which when driven high, will completely disconnect the common pin (all switches “off”).

Features:

• 2V to 6V operation
• “On” resistance: 70 Ohms @ 4.5V
• 6ns break-before-make @ 4.5V
• Wide operating temperature range: -55C to 125C

Don Luc

SparkFun: CAB-09741

Description: These are good quality IC test hooks with a male connection wire. Instead of a single hook, these have two hooks that are capable of grabbing very small points (like SOIC IC legs). Comes in a bag of five IC hooks of different colors (black, red, white, blue, and green). We use them with the Bus Pirate logic analyzer harnesses but are very cool on their own.

Wire length is 2.5″ long. Male pin easily inserts into breadboard or other standard 0.1″ connector.

Don Luc