We have now complete test boards for a CC2540 Bluetooth Low Energy with our own design.
Everything seems to be working with the microprocessor, I/Os, and timers with the exception of the Bluetooth LE communication.
We installed the Texas RF packet sniffer and we can confirm that there are no radio packets coming from the device.
We cannot rule out or narrow it down to a hardware or software issue at this point.
Practically only the I/Os mapping changed from the reference demo kit keyfob software application so very few changes in the software and none in the communication part. All the RF components and crystals in the schematics are supposed to match exactly the reference design.
Could someone suggest what the issue or typical issues could be at hardware or software level for a new (first) CC2540 implementation.
In particular, we would like to know if there is any particular setting to burn in the CC2540 level that is not happening when we download our application with the Flash Programmer.
Rob,
Has the software being used on the customer's board been tested the TI reference design board?
Also, has a basic TI software example been used for testing the customer board for verification?
CC2540 Code Examples: http://www.ti.com/tool/ble-stack
Default location after install: C:\Texas Instruments\BLE-CC254x-1.2.1\Projects\ble
Best regards,
Austin Miller
Digital Field Applications
If my reply answers your question please click on the green button "Verify Answer".
Hi Austin,
Yes, our custom software was tested and runs well including Bluetooth communication in the CC2540 Mini Dev Kit from Texas Instruments (Key Fob demo).
Our software is essentially the SimpleBLEPeripheral application included in the BLE stack release modified with few changes including moving all I/Os from Port 0 to Port 1 (with interrupts use) and using the Timer 1 to generate a PWM signal.
In our new custom board all the I/O functionality and the PWM generation is running correctly (only Bluetooth seems to not be working). Would this already mean that both the 32Mhz and 32Khz crystals/oscillators are working fine?
Also, our custom board copied from the keyfob reference design the RF and crystal sections. The only difference is that we are using the PCB Inverted F antenna instead of "Meandered".
Yes, the basic application provided with the BLE stack (both compiled and original binary) was attempted to run on our custom board and still we don't get Bluetooth to work.
Of course, we would not mind at all to send you our source code or hex, schematic and gerber files to check for any evident issues in the software or hardware.
Thank you very much !
Alex
Alex,
Are you able to use a sniffer to verify any wireless communication?
SmartRF Protocol Packet Sniffer: http://www.ti.com/tool/packet-sniffer
Also have you had a chance to review any of the following to documents for designing with an Inverted F Antenna (IFA)?
2.4 GHz Inverted F Antenna: http://www.ti.com/lit/an/swru120b/swru120b.pdf#page=3 (page 3)
Basic RF Testing of CCxxxx Devices: http://www.ti.com/lit/an/swra370/swra370.pdf
Application Note AN058: http://www.ti.com/lit/an/swra161b/swra161b.pdf#page=28 (starting with page 28 specifically).
Thanks indeed for your help. Yes, we made our design using the inverted F antenna guidelines in these docs.
Good news first. We now see with our custom board the advertising packets with the RF Sniffer and we communicate with the BTool PC application + USB BLE dongle. We can also read/write GATT characteristic values into our board (http://processors.wiki.ti.com/index.php/Category:CC2540DK_Mini_BTool_Connection)
Not so good news now. We then tried to have an iPhone 4S discover and connect to our board using the BLE-TI-DEMO IOS application (http://processors.wiki.ti.com/index.php/Category:IPhone4SBLEDemo). The iPhone application does not even discover the device when scanning for peripherals. We already had this application compiled and working fine with our application running on the keyfob demo kit hardware provided by TI. Same CC2540 application running in the keyfob demo kit and our hardware.
Bottom line, our hardware can communicate and read/write values with BTool + USB BLE dongle using BLE, however it cannot do the same with our tested iPhone app.
Any suggestion of what to look for on hardware or software?
Thank you!
Good news first. We now see with our custom board the advertising packets with the RF Sniffer and we communicate with the BTool PC application + USB BLE dongle. We can also read/write GATT characteristic values in our board (http://processors.wiki.ti.com/index.php/Category:CC2540DK_Mini_BTool_Connection)
Hi,
The proprietary CC2540 board seems to be working now with RF Sniffer, RF Studio and BTool, but still not working with iPhone.
So I preferred to start a new post focusing on the iPhone communication issue.
http://e2e.ti.com/support/low_power_rf/f/538/t/187911.aspx
Therefore you may prefer to answer here or in the new post.