The HSO-100 relay board has the following components.

• One NC/NO two state relay
• One COM/A/B three state relay
• Three digital input
• Five digital output

These devices are controlled by GPIO of CPU and Holtek HT46RU22.

Function	Chip	PIN	driver pin no
two state relay	HT46RU22	PA2	2
Three state relay	HT46RU22	PB6/PB7	0x16,0x17 (0,0)-->off (1,0)-->A (0,1)-->B
DI1	CPU	A6	6
DI2	CPU	A5	5
DI3	CPU	A4	4
DO1	HT46RU22	B5	0x15
DO2	HT46TU22	B4	0x14
DO3	HT46RU22	A1	1
DO4	HT46RU22	B0	0x10
DO5	CPU	A3	3
Factory default button	CPU	B26	0x3a

The device for the GPIO of the CPU is /dev/star_gpio.

The device file for the GPIO of the HT46RU22 is /dev/ht_gpio.

Both device file can be controlled by write the command to the device file. The format of the command is

Select pin as GPIO pin

This command is valid for the CPU only. It will setup the pin as GPIO pin instead of the alternative function.

'g'

pin

Setup the pin as input/output pin

Setup the pin as an input pin.

'i'	pin
'o'	pin

Setup the ping value as '1' or '0'

'1'	pin
'0'	pin

Read input pin

Current driver does not provide capability to read the input pin directly. However, we can use the ioctl to monitor the ping.

[To be finsihed]