Rainbow Electronics AT42QT1110-AZ - Manual (Page 24)

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9570H–AT42–02/10
AT42QT1110-MZ/AT42QT1110-AZ
6. Report Requests
6.1 Introduction
The host can request reports from the QT1110, as summarized in Table 6-1 .
Note that SPI communications are full-duplex, so the host must transmit on the MOSI pin to
keep the communications active, while reading data from the QT1110 on the MOSI pin. Failure
to do this within 100 ms will cause the device to assume that the exchange has been abandoned
and reset the SPI interface. The host should therefore send one or two “NULL” bytes, as
appropriate, on the MOSI line as it receives the 1- or 2-byte report data from the device.
6.2 First Key (0xC0)
This command returns 1-byte report in the format shown in Table 6-2 .
DETECT: 0 = no key in detect; 1 = there is a key in detect.
NUMKEY: indicates the number of keys in detect:
0 = only one key is in detect (specified by “KEY_NUM”)
1 = more than one key in detect.
ERROR: 0 = there are no keys in an error state; 1 = at least one key is in error state.
KEY_NUM: the key number (0 to 10) of the key in detect (if there is only one), or the number of
the first key to go into detection when there are more than one.
Table 6-1. Report Requests
Command Code Note Data Returned
Send First Key 0xC0 Returns the first detected key 1 byte
Send All keys 0xC1 Returns all keys 2-byte bitfield
Device Status 0xC2 Returns the device status 1-byte bitfield
EEPROM CRC 0xC3 Returns the EEPROM CRC 1 byte
RAM CRC 0xC4 Returns the RAM CRC 1 byte
Error Keys 0xC5 Returns the error keys 2-byte bitfield
Signal for Key “k”' 0x2k Returns the signal for key “k” 2-byte number
Reference for Key “k” 0x4k Returns the reference for key “k” 2-byte number
Status for Key “k” 0x8k Returns error conditions/touch indication 1 byte
Detect Output States 0xC6 Returns the detect output states 1 byte
Last Command 0xC7 Returns the last command sent to QT1110 1 byte
Setups 0xC8 Returns the setup data 42 bytes
Device ID 0xC9 Returns the device ID 1 byte
Firmware Version 0xCA Returns the firmware version 1 byte
Table 6-2. Send First Key Report Format
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
Byte 0 DETECT NUMKEY ERROR KEY_NUM