topic Re: How to Use QN9021 Bootloader in Wireless MCU

How to Use QN9021 Bootloader

zky — Fri, 04 Aug 2017 06:31:58 GMT

Hi,

It is very glad to use chip QN9021.Now i use Uart to connect its Bootloader, i met some difficulties.

1.as the datasheet shows.

So before connected ,what my UART baud rate shouled be?

2. ISP PDU has CRC(2 bytes),but i don't know how to caculate?

Could you help me with it ? or provide a example. such as input 0x01,0x02,and then out put is 0xaabb.or i will preciate

if you can provide a C language example.

3.when i want to download a appliacation to flash? Which Steps is necessary?

as the datasheet shows:

Thanks for your reading.

I am waiting for your replay.

Re: How to Use QN9021 Bootloader

gerardo_rodriguez — Thu, 10 Aug 2017 00:09:06 GMT

Hello,

The initial baud rate depends on the crystal used for the QN902x. If you are using a 16MHz crystal, the baud rate is 9600 and if you are using a 32MHz crystal, the baud rate is 19200.

Have you checked out the QBlue ISP studio included in the QBlue SDK? It is a tool to download application binary file into QN902x devices. It connects to a USB to serial device and communicates with the bootloader of the QN902x. The baudrate is handled automatically depending on the crystal configuration.

The ISP programming flow and CRC is handled by this tool so you don't have to implement it on your own.

You can also check out the QN9020 Quick Start Guide for steps on how to use the QBlue ISP studio.

Regards,

Gerardo

Re: How to Use QN9021 Bootloader

zky — Thu, 10 Aug 2017 01:01:18 GMT

Hi,

Thanks for your help very much.Your reply is very helpful!

Thanks.

张恺钰

技术部

南京西尔特电子有限公司

南京市江宁区紫金创业特别社区紫金2路1号1号楼

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EMAIL：zky@xeltek-cn.com

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