Using motor shield in Genuino (Arduino) 101

Summury

•Adafruit library v1 do not support the Intel Curie system, so I have coded it myself.
•Even if pin 13 of the shift register is set low, the shield will not work. Therefore it need to connect to GND of the hardware.

Contents

I purchased a Chinese OEM motor shield to drive dc motor with arduino 101.
I used a library compatible with a adafruit v1, but it was not compiled.
Library v1 does not support Intel Curie system.
Compared to the UNO, I found the pin layout is same.
So I coded without useing the library.

First, pin arrangement between Shift Register (74HC595) and Arduino is shown in the table below.

	Arduino	74HC595
Data	GPIO8	PIN14(DS)
Clock	GPIO4	PIN11(SH_CP)
Latch	GPIO12	PIN12(ST_CP)
Enable	GPIO7	PIN13(OE)

And, arrangement between Shift Register and motor driver(L293D) is shown below.

	74HC595	L293D
M1	Q2	IN1
	Q3	IN2
M2	Q4	IN3
	Q1	IN4
M3	Q0	IN1
	Q6	IN2
M4	Q7	IN3
	Q5	IN4

Therefore, the data pin to transfer to Shift Register is GPIO8, Shift Register Latch is GPIO12, Shift Register Clock is GPIO4.
And the forward, backward data for motor 3, 4 are as follows.

	Data (LSBFIRST)
Forward	0x81 (10000001)
Backward	0x06 (00000110)

However the pin 13 of Shift Register must be grounded, but it is connected to VCC through a register.
So, I outputed Low at Arduino GPIO7 but shield did not work, and pin 13 of Shift Register stays 1mV(higher than normal GND). So, I removed the register and connected it to GND, andmotor shield worked.

The motor shield v2 of Adafruit might be compatible but price is expensive.