Informations about the hardware interface between the i.MXL and the TSC2102.
This chip is a "SMART" 4-Wire Touch Screen Controller with Stereo DAC and HP Amplifier. It is used on the DevFull board but any good electronics engineer should be able to add it to its DevLight. It is although possible to solder this chip directly on your LQ043 adapter board, if you have one.
Hardware interface with the i.MXL
Configuration and data exchange is done through the SPI bus n°2 (SPI2).
The SPI 2 port is shared with the LCD interface of the i.MXL (these signals are present on the DevLight V2 LCD connector).
Configuration is done through SPI2 bus and audio data exchange through SSIA
|SPI2_TXD/SPL_SPR||MOSI||SPI MasterOut SlaveIn|
|SPI2_RXD_1/PS||MISO||SPI MasterIn SlaveOut|
|PortB 17/SSI1_TXDAT||SSn||SPI Chip select|
|Reset (on Reset switch)||RESETn||Global reset signal|
- i.MXL/DevLight SPI Chip Select signals are not used by Linux SPI infrastructure; it needs multiple chip select (one for each chip connected on the bus), and so GPIOs are used for that purpose.
- Chip interrupt is on Port D because Port B has already some and interrupt are shared on the same port.
Self-made adapter board
For those who would like to test this component on their DevLight or their custom boards, take a look at this link: http://www.farnell.fr and type '1426186' as part to search.
This is a small pcb converting a tssop32 to 2 rows of 2.54mm holes...
SSI test tool