Power Specifications

Questions and discussion about The WiPy 1.0 board and CC3200 boards.
Target audience: Users with a WiPy 1.0 or CC3200 board.
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JimTal001
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Power Specifications

Post by JimTal001 » Thu Jul 30, 2015 11:25 pm

Can anyone point me to the power Specification for the WiPy. I would need to put it into sleep mode 98% of the time.

Thanks

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danicampora
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Re: Power Specifications

Post by danicampora » Fri Jul 31, 2015 8:12 am

Hello JimTal001,

We will add detailed tech specs with this info to our website. In the mean time, here they are:

Active (WiFi Station mode) MCU @ 80MHz ---> 14mA
Active (WiFi AP mode) MCU @ 80MHz ---> 45mA
Suspended (WiFi Station mode) ---------------> 850uA
Suspended (WiFi AP mode) -------------------> 30mA
Hibernating (WiFi is always disabled) -------------> 5uA

The suspended mode is really cool because WiFi events can wake up the WiPy (connect/disconnect, any socket activity).

Cheers,
Daniel

JimTal001
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Re: Power Specifications

Post by JimTal001 » Fri Jul 31, 2015 1:25 pm

Thanks for the info Daniel.

1. Why is the power requirement so high in suspended WiFi AP mode as compared to suspended WiFi Station mode?
2. In Wifi AP mode is it possible to configure the WIPy as a DHCP Server?
3. When waking from Hibernation mode (5uA) is it possible to keep the Wifi module in a disabled mode (off) in order to minimize power?

My application requirement is to wake (based on timer) only to collect sensor data, store the data, then return to hibernation mode. When a user needs to retrieve wireless data, a button is pressed to wake the Wifi in AP mode.

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danicampora
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Re: Power Specifications

Post by danicampora » Fri Jul 31, 2015 6:21 pm

Hi JimTal001,
1. Why is the power requirement so high in suspended WiFi AP mode as compared to suspended WiFi Station mode?
Because an access point needs to fulfill certain requirements like sending beacons, keeping the receiver ON all the time, etc. This needs to be done like this in order to be fully WiFi compliant.
2. In Wifi AP mode is it possible to configure the WIPy as a DHCP Server?
Do you mean that it will be able to assign IP addresses automatically? In the case the answer is YES, and this is the default setting. Bare in mind that in AP mode only ONE other device can be connected to the WiPy.
3. When waking from Hibernation mode (5uA) is it possible to keep the Wifi module in a disabled mode (off) in order to minimize power?
It is possible, but I haven't implemented this feature yet. In principle, WiFi is always ON, because, due to the way the CC3200 has been designed, access to the serial flash must be done via the Network Processor, and when WiFi is OFF, accesing the /flash file system is not possible. This means than any file operation on /flash will fail. I could add a method to disable WiFi on demand

Code: Select all

WLAN().disable()
, but the user needs to keep in mind that when doing so accessing a file on /flash will always raise

Code: Select all

OSError
. File operations on an SD card won't be affected by this.

Thoughts?

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danicampora
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Re: Power Specifications

Post by danicampora » Fri Jul 31, 2015 6:55 pm

Remark on the previous post:

The issue with file operations while WiFi is disabled only affects /flash file system. The SD card has no issues with this.

JimTal001
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Re: Power Specifications

Post by JimTal001 » Sat Aug 01, 2015 1:19 pm

Hello Daniel,

Assuming you implement the WLAN().disable() functionality can you estimate the following:

Active (WiFi Disable mode) MCU @ 80MHz ---> ? mA
Active (WiFi Disable mode) MCU @ 40MHz ---> ? mA

Also, since the WiPy does not have an SD card do you have one to recommend?


Thanks

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danicampora
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Re: Power Specifications

Post by danicampora » Sun Aug 02, 2015 11:22 am

I did some testing and also checked the CC3200 datasheet again.
Active (WiFi Disable mode) MCU @ 80MHz
The current only drops 800uA, therefore I don't think that the benefit is worth the hassle. So instead of 14mA it consumes 13.2. The CC3200 Network Processor was designed from the ground up to be ultra low power, hence when in Station mode and not connected the Network processor itself only consumes ~300uA. Instead of disabling WiFi completely, just do:

Code: Select all

WLAN(WLAN.STA)
WLAN().disconnect()
Doing this the total current @80MHz is ~13.5mA
Active (WiFi Disable mode) MCU @ 40MHz
This is not possible, when the MCU is active the frequency is fixed to 80MHz. The CC3200 doesn't support frequency scaling.

I discovered something else. In Suspended mode the current can be lowered to ~300uA if entering this mode in Station mode and NOT connected to any network.
Also, since the WiPy does not have an SD card do you have one to recommend?
We launched an expansion board that is also available via our webshop. The microSD card socket is of the luxury push-push type, and besides that it also has some other cool features. Check it out here: http://wipy.io/product/expansion-board-pre-order/

phsdv
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Re: Power Specifications

Post by phsdv » Wed Nov 08, 2017 8:43 am

danicampora wrote:
Fri Jul 31, 2015 8:12 am
We will add detailed tech specs with this info to our website. In the mean time, here they are:

Active (WiFi Station mode) MCU @ 80MHz ---> 14mA
Active (WiFi AP mode) MCU @ 80MHz ---> 45mA
Suspended (WiFi Station mode) ---------------> 850uA
Suspended (WiFi AP mode) -------------------> 30mA
Hibernating (WiFi is always disabled) -------------> 5uA
I finally found an interesting application for my Wipy (v1) however I am running into a much higher consumption. in WiFi AP mode the board is consuming 70mA base instead of 45mA, with peaks up to 300mA. The power supply is only capable of ~100mA so the current peaks are killing the application. Adding a bunch of capacitors did not help. I placed an ceramic 10uF and 2xelco on both 3v3 and 5V (Vin) but no improvement :cry: Even adding 560uF or 1000uF on the 5V did not change a thing.
I will try station mode later, however still think that the peaks will kill it as well. Anyone any advise?

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