cc3200 power saving mode

[venu 0]

Hi All,

I just started using cc3200 launch pad. I could get a external LED blink from webserver running on cc3200. I used SimpleWebServerWifi example to achieve it. 

Now I wanted to power the launch pad using 2 AA batteries. I could power it as per instructions, but it is not lasting more than 1 hour. 

Can someone tell me how to enable power saving mode? I want to wakeup only GPIO pins after webserver receives any request. Please help me.

 

Thanks

Venu

[spirilis 1,265]

That's not really happening yet.  I'm also not sure you will ever expect to see good battery life from these MCUs on two AA batteries while having the *webserver* running continuously... I think TI's "Runs on 2 AA's for a year!" claim is for a transmit-only device that wakes up once in a blue moon to send data to the cloud.  Running a webserver on the chip, even if you offload it to the WiFi network processor's built-in webserver (which you aren't doing here; Energia support for that is also forthcoming), is a power-hungry use of the chip because it keeps the WiFi subsystem spun up all the time so it's available for connections.

 

Low-power support for sleep(), sleepSeconds() and suspend() in Energia is in place on MSP430 and the strawman functions are there for Tiva/Stellaris (not actually enabling low-power mode yet), but not for CC3200 yet ... There's a lot of work yet to be done for that one.

[venu 0]

Thanks a lot Spirilis for the explanation. Got it  

Does the hardware in CC3200 supports it? By looking at power modes in CC3200 document, i thought i can keep the MCU in hibernate mode and keep the network processor as active mode. But as you said, webserver itself may consume lot of power. I will explain my application, can you please suggest right way to do it. 

 

I want to rotate a stepper motor wirelessly from mobile or Raspberry pi. Mostly it will be a very small rotation and it is controlled very rarely may be once in a day. I want to power it using 2 or 4 AA batteries.

I am fine using any technology, all i want some wireless connection between my raspberry pi and the board. I was thinking of using some bluetooth low energy module, then i saw CC3200 and thought wifi is easy to use

Can you please suggest any board, which i can use for this application. 

 

Thanks in advance.

 

-Venu

[chicken 630]

First step would be to specify what latency is acceptable for your use case.

 

A common pattern for applications that can live with high latency (i.e. long response times) is for the remote device to periodically check a server for updates. E.g. every 10 seconds the CC3200 could wake up, connect to WiFi and check a web service running on the RasPi for an updated stepper position, if required rotate the stepper, then go to sleep again.

[spirilis 1,265]

Yeah, perhaps once we get real low power modes working in Energia this would be an appropriate use of the CC3200.  WiFi is a nice easy way to do things like this IMO.  Just power-hungry when it's active.

[venu 0]

Thanks chicken for your input. 10 seconds latency is fine with me. I can do that, every 10 seconds check with raspberry pi webserver whether it has any input and i can interact with raspberry pi webserver to issue the command.  Do you have any example hibernate code? As spirilis was saying, the Energia is not ready for this.  Do I need to use TI CCS do to this? Can you please suggest.

 

Thanks

Venu

[chicken 630]

I haven't played much with the CC3200, so no practical advice from me. There are some examples on TI's website:

http://processors.wiki.ti.com/index.php/CC32xx_SDK_Sample_Applications

e.g. this one looks like a good start to figure out the basics:

http://processors.wiki.ti.com/index.php/CC32xx_Sleep-DeepSleep_Application

 

@@spirilis probably can comment what to watch for when trying to do this with Energia instead of CCS.

[spirilis 1,265]

You can probably get started with CCS and one of the FreeRTOS or TI-RTOS examples. I haven't used those myself though so YMMV. It will be a learning experience I'm sure...

 

Sent from my Galaxy Note II with Tapatalk 4

[BigG 1]

Low-power support for sleep(), sleepSeconds() and suspend() in Energia is in place on MSP430 and the strawman functions are there for Tiva/Stellaris (not actually enabling low-power mode yet), but not for CC3200 yet ... There's a lot of work yet to be done for that one.

 

Any status update on the cc3200 low power mode/ sleep functionality