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CC2530 issues (boot up with CR2032 issue / search for pan id issue / dsss issue)

Johnson Liu
Prodigy 20 points

Other Parts Discussed in Thread: CC2530

Hi, I am Johnson

 

About the CC2530, there are some questions about power mode and DSSS.

Would you please help us for those issue ?

 

1. The CC2530 failed to boot up issue.

 We use CR2032 for the power source and we find the CC2530 will  fail to boot up when using a lower power battery (voltage : 2.8 V) even the voltage is higher than the minimum requested voltage (2.0V).

We learned that it may be caused by the suddenly high power consumption which triggers the protection mechanism of CC2530.

 

We find out the CC2530 usually failed on ZDOInitDevice (in zdapp.c) function when booting.

To prevent it, we tried the following modifications in the end device FW :

a. Lower the signal strength of RF transmits by modifying the regTxpower (in mac_radio.c) to 0x05 and lower the electric consuming form 34mA to 23mA

b. Delay the execute time of ZDOInitDevice function for 10 seconds or just to trigger it manually by changing the definition HOLD_AUTO_START (in zdapp.c),

 

We found both methods didn't help.

Due to the difficulty of changing the hardware battery design, we're wondering if there's any suggestions that we can do on the firmware side to avoid this issue?

 

 

2. The full scan when searching for the pan id issue.

We find that there is a definition MAX_CHANNELS_24GHZ (in f8WConfig) that automatically switches  the scanning mode between one specific channel and full channels when finding pan id.

The end device will scan all of 26 channels by default and this is why the end device try to find the pan id on channel 20 even we had set the channel 26 as the default channel.

We also get the same behavior on CC2530 EM with the sample FW.

For this channel jumping behavior, we're wondering if you can help us with:

a. What's the pros and cons when I choose to scan full 26 channels to find pan id? Is there anyone using this configuration?

b. What's the rules of finding the suitable channels and what's the trade-off?

c. Is there any technical note regarding this issue?

 

3. The DSSS issue.

About the Zigbee DSSS, we learned that it is implemented in the CC2530 chip.

Is there any technical note regarding this issue?

Should we use any particular settings or configurations if we want to improve the reception and are there any trade-offs?

 

Thanks.

  • 0
    Prodigy 20 points

    About the issue 1.

    I also try to lower the RF and sensitivity power today and the device can boot with 2.8V battery.

    But the side-effect is that it will serious effect the ability of RF sensitivity. It doesn't work.

    I find that when the device is starting search network, it will take about 500ms on higher power comsumption mode (about 34 mA) and this is the cirtical step of this issue.

    I can not find the source code about network (pan id) searching, It should be in the lower network layer that I can not access.It there any way to modify this to lower the power comsumption on network searching step?

  • 0 in reply to Johnson Liu
    TI__Mastermind 36415 points

    Johnson Liu, 

    The issue is the high internal resistance of a C2032 coin cell battery. It is approximately 200-500 Ohms, this means that if you try to pull more current than a few milliamp's you will have a high voltage drop across the battery terminals.

    The way to get around this is to ensure that your application only operates in short bursts, (which you would need to characterize on a bench supply setup) and then add enough local decoupling capacitance to enable the CC2530 to "survive" during the active period.

    Regards,
    /TA