topic Re: BT Continuous TX Output Power Test 8997 in Wireless MCU

BT Continuous TX Output Power Test 8997

eoin_oconnell — Fri, 07 May 2021 09:42:03 GMT

Hi all, My HW setup is an imx7 with a custom carrier board where the wifi module(AW-CM276NF) is present, this module has the Marvell 8997 BT/Wifi module.

I am currently using some test scripts to activate a continuous TX mode of the module.https://github.com/hychiang73/wlan_script/blob/master/bt_ctx.sh

I measure the output power conducted at the module's output connector and I only see around -20dBm. I am measuring the power in a 10MHz bandwidth, peak is around -30dBm but integrated across the bandwidth I get a total power of around -20dBm

How can I change the output power or put it in such a mode that I get the maximum output of around 4dBm for Bluetooth, I am measuring at the AUX antenna port..

Re: BT Continuous TX Output Power Test 8997

weidong_sun — Sat, 08 May 2021 06:16:09 GMT

Hi,

The following commands are for you refrence:

1. hcitool -i hci0 cmd 3f 00ee 01 0N --> N is BT max TX power, (Pls try out different values)

2. hcitool -i hci0 cmd 03 0003 --> HCI reset is to make the change on max Tx power take effect.

3. hcitool -i hci0 cmd 03 001a 03 --> Enable Page Scan and Inquiry Scan

4. hcitool -i hci0 cmd 06 0003 (BT Test mode)

5. Run CBT (Link mode) and check the BT TX output power.

Have a great day!

B.R,

weidong

Re: BT Continuous TX Output Power Test 8997

eoin_oconnell — Mon, 10 May 2021 09:23:23 GMT

Thanks for the detailed reply, but you left out the vital last step.

What do you mean by run CBT (Link Mode) ?

I tried your 4 steps and no output on the spectrum analyser

Re: BT Continuous TX Output Power Test 8997

weidong_sun — Mon, 10 May 2021 11:28:56 GMT

Dear eoin_oconnell ，

CBT , here means CBT Bluetooth Tester. for exmaple, CMW270/CMW500.

when bluetooth enters TEST Mode, you can use it to connect with bluetooth.

spectrum analyser can't be used to measure Power.

Have a nice day!

B.R,

weidong