EasyDriver testing

The EasyDriver is a bipolar stepper motor driver:

• based on the A3967
• delivering up to 750mA per phase
• available from Sparkfun

These are some notes on wiring up the EasyDriver for testing, blatantly copied from the original engineers notes on the front page of the EasyDriver site.

Solder the headers shown in the photos above and below.

Then wire up this:

• On the left is a 555 timer configured as an astable
• The small capacitor closest to the 555 is a 100nF bypass
• The resistor on the left is R1 and is 1kΩ
• The resistor on the right is R2 and is 100kΩ
• The capacitor at the top is 22nF
• This configuration of the 555 produces 300 Hz at close to 50% duty
• The red wire from pin 3 of the 555 goes straight to STEP
• DIR is tied to GND
• The electrolytic at the bottom is 47nF as recommended by the A3967 datasheet
• The yellow and green leads at the bottom go to a 12V battery
• The RGBY leads in the bottom right go to the motor

The STEP pin seems to draw quite a lot of current (over 100mA when driven to 5V) even though the datasheet says it should draw < 1µA.