Quick background: Making a line follower for a competition. Arduino is wired up to a motor driver, which drives micrometal gearmotors that I'm sure you have seen around.
Problem: Stanby pin is not receiving enough voltage? Well, motors don't get voltage.
Parts:
Arduino Uno
Motor Driver: http://www.robotshop.com/ca/sfe-dual-motor-controller-1.html
... Specs: http://www.robotshop.com/ca/content/PDF/tb6612fng-datasheet-rob-09457.pdf
9V (to power the Arduino, driver, etc.)
4xAA (6V to the motors)
Pins:
Currently, the Arduino is hooked to the motor driver as follows... (digital pins)
0: A_in_2
1: A_in_1
2: STBY (Standby)
3: PWM A
4: B_in_1
5: NC (not used)
6: PWM B
7: B_in_2
Driver is hooked to motor as follows:
AO1: Motor A (-) terminal
AO2: Motor A (+) terminal
BO1: Motor A (-) terminal
BO2: Motor A (+) terminal
V_M: Battery pack (+) wire
V_cc: 5V pin of Uno
All grounds are tied together, and routed to GND pins of the Arduino, and the negative (-) wire of the motor battery pack (4AA pack)
A program currently sets STBY, pin1 (A_in_1) to HIGH; all others are brought LOW. A PWM signal of 127 is then written to
pin3 (PWM A). The voltage on the PWM pin in relation to ground is about half of V_cc, as expected.
The goal was to simply turn on one motor (motor A) at half speed. It does not work.
On testing with the voltmeter, everything seems correct except the following:
- STBY pin, in relation to ground, has a voltage of only ~4V (a bit less than 4V)
- AO1 and AO2 have no potential difference (voltage) between each other; seems to be no output.
The motors were confirmed to work before hooking to the motor driver.
Anyone see anything wrong, or anything that could help? If there are ANY questions, please ask. Thank you so so much for any advice to come,
Camalaio.
EDIT: New development. A_in_1 and A_in_2 are both HIGH, but only one is brought high; the other is brought low. Defective Uno? I confirmed this directly on the pins off the Uno: both pins are HIGH. No serial communication is going on, and only 1 is brought HIGH.
EDIT: Fixed. Arduino IS defective; used different pins.