1. Power on the product, then load the BT test firmware.
Enable Bluetooth function
1) echo 0 > /sys/class/rfkill/rfkill0/state // Bluetooth power OFF (depends on platform)
2) echo 1 > /sys/class/rfkill/rfkill0/state // Bluetooth power ON (depends on the platform)
3) brcm_patchram_plus--enable_hci --no2bytes --tosleep 200000 --baudrate 115200 --patchram /system/etc/firmware/bcmdhd.hcd /dev/ttyS0 // Please change the patchram path and UART port accordingly.
4) hciconfig hci0 up Since the RF switch for Bluetooth is located in the Wi-Fi nvram file, it is also necessary to activate Wi-Fi.
5) ifconfig wlan0 up Wi-Fi is up
2. The IQ instrument loads the corresponding waveform file, which can be provided by the original manufacturer or the IQ instrument vendor.
After loading, configure the frequency, output power, bandwidth, and a packet count of 1000. As shown in the figure:
Figure 1: Instrument Packet Interface
3. Use the following command to perform the RX sensitivity test.
Figure 2, Command Details --- Referencing the Synaptics BT RF Test Commands for Linux-v09 Document
Organized command:
BLE_RX Test:
BLE Rx Command (LE_Receiver_Test): LE_1M
hcitool cmd 0x03 0x0003
hcitool cmd 0x08 0x001d 00 --CH0_2402
hcitool cmd 0x08 0x001f
hcitool cmd 0x08 0x001d 13 --CH19_2440
hcitool cmd 0x08 0x001d 27 --CH39_2480
BLE Rx Command (LE_Receiver_Test): LE_2M
hcitool cmd 0x03 0x0003
hcitool cmd 0x08 0x0033 00 02 00 --CH0_2402
hcitool cmd 0x08 0x001f
hcitool cmd 0x08 0x0033 13 02 00 --CH19_2440
hcitool cmd 0x08 0x0033 27 02 00 --CH39_2480
BLE Rx Command (LE_Receiver_Test): LE_S8_S2
hcitool cmd 0x03 0x0003
hcitool cmd 0x08 0x0033 00 03 00 --CH0_2402
hcitool cmd 0x08 0x001f
hcitool cmd 0x08 0x0033 13 03 00 --CH19_2440
hcitool cmd 0x08 0x0033 27 03 00 --CH39_2480
4. After entering the command for the product, the IQ instrument starts sending 1,000 packets. Click Play.
Figure 3, the instrument starts sending packets.
By calculating the last two hexadecimal digits and converting them into decimal numbers, you can determine the number of good packets received. Using this formula, you can calculate the PER, and the standard is that the PER should be within 10%.
PER = (1000 - 960) / 1000 = 40 / 1000 = 4%
Frequently Asked Questions (FAQ)
1. What could be the reason for not displaying the number of received packets after entering the hcitool cmd command?
First, check if the hardware connections are correct. Next, confirm whether the hcitool cmd command is accurate. Finally, it's about IQ.
Are the waveform files and frequency settings used correct? These are usually the three main reasons.
2. What should be done if the measured reception sensitivity is relatively poor?
After ruling out issues such as hardware connections, instrument cable loss settings, and product firmware versions, you can measure whether the sensitivity of adjacent channels is consistent. If it is 2~3dB worse than the specification, RF matching can be used to improve it. If the difference is more than 5dB, consider whether the RF switch configuration for BT in the NVRAM is correct, as well as potential issues with the RF trace design on the PCB.
3. When testing reception sensitivity, can the number of received packets be displayed in real-time?
No, you must first prepare to receive, then the instrument sends the packets, and finally, the product receives the packets and calculates the results for display. However, the number of packets sent can be set manually; you only need to calculate the PER.
4. Is it possible to test the reception sensitivity of all channels simultaneously?
No, you can only test the receiver sensitivity of one channel at a time. When testing another channel, the instrument needs to switch to the corresponding channel to send packets.
5. Can users modify the parameters in the BT hcd configuration file?
No, this can only be modified based on the customer's requirements provided by the original manufacturer.