The seesaw has built in NeoPixel support for up to 170 RGB or 127 RGBW pixels. The output pin as well as the communication protocol frequency are configurable. Note: older firmware is limited to 63 pixels max.

The module base register address for the NeoPixel module is 0x0E.

Function Registers

Register Address	Register Name	Register Size	Notes
0x01	PIN	8 bits	Write Only
0x02	SPEED	8 bits	Write Only
0x03	BUF_LENGTH	16 bits	Write Only
0x04	BUF	32 bytes	Write Only
0x05	SHOW	none	Write Only

PIN (0x01, 8bits, Write Only)

This register sets the pin number (PORTA) that is used for the NeoPixel output.

SPEED (0x02, 8bits, Write Only)

The protocol speed.

0x00 = 400khz

0x01 = 800khz (default)

BUF_LENGTH (0x03, 16bits LE, Write Only)

the number of bytes currently used for the pixel array. This is dependent on when the pixels you are using are RGB or RGBW. 2 Bytes, little endian order

BUF (0x04, 32 bytes, Write Only)

The data buffer. The first 2 bytes are the start address, and the data to write follows. Data should be written in blocks of maximum size 30 bytes at a time.