Here we are. In the post, you will find (i hope) useful information to upgrade your module with HC05 firmware.
CSR support website provides a complete SDK with very useful tools. You only have to register to access to bluesuite 2.4 download page.
During the installation, let's talk about the pinout needed to gain write access to the internal firmware.
CSR BC417 chip native firmware flashing is possible by SPI connection.
SPI pinout :
- PIN16 : CSB
- PIN17 : MOSI
- PIN18 : MISO
- PIN19 : CLK
On PC side, CSR toolkit uses LPT port to emulate SPI protocol.
With few resistor, you can make your own programmer.
You will need a 3,3 V power source, I opted for a USB 5V with 3,3 V regulator.
When it's done, you will be ready to read the next post about firmware upgrading commands.