T.I. BLE USB MCU Programming Trouble (CC2540)

Thread Starter


Joined Jan 29, 2020
Hello Everybody!

I am trying to program/communicate with the CC2450 BLE IC, which is a transceiver/microcontroller. My computer is having trouble recognizing the device. It does not show up in Device Manager. I've tried the T.I. tools for trying to communicate with it. I've downloaded the BLE Stack from TI and the BTool/PacketSniffer software. I'm not sure it is a hardware or software issue. I think its more of a HW issue. I used EasyEDA to design the PCB, it doesn't provide a way to impedance match, so needless to say, my differential pairs are not 90 ohms (nor differential probably). I also have the incorrect connector to my board that I wanted. It is an USB-A on my board, so I cut a USB cable in and soldered it to effectively make a USB A to A connector. Not sure if that would severely effect the USB signals (D+/-). Any help would be great!

Some other info...
- Power is good to the IC, all the digital outputs are high.
- I didn't GND the pad under the IC at first, so I had to Dremel through the back and GND it.
- IC power is 2.8V
- Reset_N is high
- IC has not been programmed. Unable to communicate with it.

Some Questions...
- What would happen if the IC pad wasn't gnded?
- How do you program a raw IC via USB.

If you guys have any answers/input on my schematic and about my issue it would be appreciated.

Thank you!