Powering the CC2541 for use with the CC debugger

Sahil Shah

Other Parts Discussed in Thread: CC2541

Hi all,

I've poured over there forums, been through the documentation back and forth, updated the debugger firmware, and have made sure everything is connected properly countless times. However, I still cannot get the CC debugger to recognize the Bluetooth chip (still shows the static red light).

Here are my connections as best as I can describe them:

CC2541 Pin Connections (mounted on a custom PCB, with incorporated antenna)

28, 27, 24, 29, 21 = 3 V power supply for analog pins each with decoupling capacitors at 1 nF

39,10 = same 3 V power supply for digital pins each with decoupling capacitors at 1 nF

40 = connected to 1 uF capacitors as specified in documentation and then grounded

22,23 = pins connected to a 32 MHz crystal oscillator

CC Debugger Pin Connections

1 = same ground as above

2 = same 3 V power supply as above

3 = Debug clock connected to pin 34 (port 2.2) on CC 2541

4 = debug data connected to pin 35 (port 2.1) on CC 2541

7 = RESET_N connected to pin 20 on CC 2541 (connected with a 2.5 kOhm resistor in series and grounded capacitor in parallel as shown in the diagram)

I'm sorry that this question has been answered many times, but I just can't seem to figure it out. Any help would be greatly appreciated.

EDIT: I should also mention I have updated/reinstalled the debugger drivers multiple times but just can't get it to work after following the directions in the documentation completely. Do I have to configure the Bluetooth chip via software before I can use the debugger or something? I thought the purpose of the debugger was to allow me to program the chip AFTER the connection, not prior?

over 13 years ago

0 Cedric Saab over 13 years ago

Prodigy 230 points

Hi,

Did you power up your board with an other source than the CC Debugger's? CC Debugger Pin 2 can not power the board.

If you want to power your board using the CC Debugger you need to connect CC Debugger PIN 2 to 9.

0 Fredrik K over 13 years ago

TI__Guru** 106705 points

Hi Sahil,

Is the EPG of the CC2541 connected to ground?

The recommended decoupling capacitor values are:

100nF for pin 10, 21 and 24

1 uF for pin 39

pin 27, 28 and 29 should share 1x 100nF and 1x 220pF.

/Fredrik

0 Sahil Shah over 13 years ago in reply to Cedric Saab

Prodigy 100 points

Hi Cedric, thanks for your reply.

I have an external 3 V power supply. It is powering each of the power-in pins on the CC 2541 (connected in parallel), as well as Pin 2 on the CC debugger (also connected in parallel).

I am not using Pin 9 to power the board - I am powering the CC debugger from my 3 V supply with pin 2; pin 9 is floating.

Would using pin 9 help?

Thanks,

Sahil

0 Sahil Shah over 13 years ago in reply to Fredrik K

Prodigy 100 points

Hi Fredrik, thanks for your reply.

I apologize, I don't know what EPG means. Pin 1 on the CC 2541 is connected to the ground, the same ground that pin 1 on the debugger is connected to.

Would the values of the decoupling capacitors really make that much of a difference? I see how programming the chip and it's performance will be affected, but right now I'm just trying to get it to connect.

Thanks,

Sahil

0 Cedric Saab over 13 years ago in reply to Sahil Shah

Prodigy 230 points

No, Pin 9 can be used only if you want to power the board via the CC Debugger. You don't need to connect it if you are using an external power supply.

Sorry I have no more idea except checking if the CC debugger is working well (Have you tried to program something else? a module from one of TI demo kits) and checking if the CC2541 is well mounted according to TI recommandation and not damaged.

Good luck,

0 berms03 over 13 years ago in reply to Sahil Shah

Expert 1020 points

I believe EPG is referring to the pad under the cc2541. This pad needs to be connected to your ground layer with many vias. This is used for the primary ground of the chip. If this isn't connected to ground there can be many issues with the chip.

0 Sahil Shah over 13 years ago in reply to berms03

Prodigy 100 points

Ah I see, yes the EPG pad is connected on the PCB as far as I know. Would capacitors be an issue on getting the debugger to connect-I can only see it being an issue with the actual performance, not the connection.

0 berms03 over 13 years ago in reply to Sahil Shah

Expert 1020 points

do you have the EPG pad tied to your ground plane with multiple vias?

0 Chatto over 13 years ago in reply to Sahil Shah

TI__Genius 12545 points

Sahil,

The different supply decoupling caps should not affect your ability to connect to the CC Debugger. However, the lack of proper decoupling will diminish the performance of the chip on a number of levels.

Is it possible for you to show your schematic?

Also, when you power the device, what does the voltage at the RBIAS pin and DCOUPL pin?

0 Eng351 over 13 years ago in reply to Chatto

Genius 4125 points

Also do you have a 56K resistor from pin 30 to ground (Ibias)?

0 Sahil Shah over 13 years ago in reply to Chatto

Prodigy 100 points

The internal resistance voltage RBIAS is 0.52 V and the DCOUPL voltage is 2.1 V. Where can I find out what I should be seeing?

Also, the ground is connected as expected.

I'm using the schematic on page 24 of the data sheet, but I can try to upload one soon.

Thanks,

Sahil

0 Chatto over 13 years ago in reply to Sahil Shah

TI__Genius 12545 points

Sahil,

The RBIAS voltage should setup close to 1.2V, while the DCOUPL voltage should be around 1.8V when the chip is ON.

The schematic on pg 24 of the data sheet is representational and the actual reference design should be followed while designing the board
http://processors.wiki.ti.com/index.php/Category:BluetoothLE#Reference_Designs

0 Sahil Shah over 13 years ago in reply to Chatto

Prodigy 100 points

Thanks for the link! I'll build this and work through it-now that I can see exactly what I have to build, I'm sure the voltages will be correct after some trial and error.

Appreciate all the help everyone,

Sahil

0 patrick nefos over 10 years ago in reply to Sahil Shah

Expert 1850 points

Sahil,

Did you find why CC Debugger could not see (green) the Bluetooth chip?

I have same problem.

Patrick

0 Mohammad Kouhani over 9 years ago in reply to patrick nefos

Prodigy 10 points

I am having the same problem. Did anyone found a solution?

0 patrick nefos over 9 years ago in reply to Mohammad Kouhani

Expert 1850 points

This worked for me... -- Patrick

With no jumper at R2 (default) and NO Battery, run a jumper on debug header smt pins P2 to P9 so that CC Debugger senses itself and powers the board at 3V3. Connect CC Debugger and then hit CC debugger reset button. Hopefully you will get a green.

0 Li over 8 years ago in reply to patrick nefos

Prodigy 240 points

Hi Patrick,

May I ask what you mean by R2?

Thanks

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Powering the CC2541 for use with the CC debugger