Recent Bluetooth initialization failed on ACC on/off:
So summarize the entire Bluetooth initialization process (based on the CSR 8811 module via UART and Car Connection):
I. On-chip power-down 8811 module reset pin-Not every moudule needs to do this.
Two. Set UART band rate to 115200,,CSR general first low sketch error rates are relatively small, through this speed chip will automatically identify band
Three. Continue to send BCSP link establish build process until successful (in three stages), similar to three handshake
Four. If 3 BCSP is established successfully, it is necessary to write to the chip Pskey
List some of the commonly used Pskey:
1.pskey_ana_ftrim set the chip crystal oscillator, according to the different chip manufacturers to decide
2.csr_pskey_ana_freq Configuring the Bluetooth core firmware with a special always the same frequency
3.PSKEY_UART_CONFIG_BCSP CSR defaults to the BCSP of the walk, but by configuring the UART control flow is also through this Pskey
4.csr_pskey_uart_baudrate this pskey to focus on, why the front have band rate, but also need to reset it. The reason: Starting the chip will automatically recognize band rate, but if you want to change the chip Pskey chip will also think is 115200 (previous), so you need to pull up the speed, to reconfigure the Pskey
Each speed can be referred to another article of my
http://blog.csdn.net/xiaoxiaopengbo/article/details/50434721
Pskey There are many, different functions need to be configured with different Pskey
Five. Write Pskey success, temporarily will not work, need to execute a bccmd protocol warm reset command,chip response ack to be effective
Six. The data speed received by the chip is then 921600 to receive, so the UART is also reconfigured to set the corresponding baud rate
Seven. It is necessary to re-establish BCSP after step six linker
Eight. So far, here are some of the interactive processes.
The order can look at its own adjustments, and a bunch of HCI command interactions are not covered in this article.
OK, finish a series of work, OK, initialize successfully