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pic24fj128ga310 + CCS 5.051 = DEEP SLEEP mode not working!
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Ttelmah



Joined: 11 Mar 2010
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PostPosted: Tue Aug 30, 2016 1:06 am     Reply with quote
And (of course), if the pins are not connected, what are you doing to stop them floating?. You do understand that a pin should not be left as an input, with nothing driving it, if you want low power?. If a pin 'floats' into the transition region, power consumption _will_ shoot up.

For low power design, every pin must be driven. Either externally with a circuit, or internally by switching it to being an output.

This also very much applies to the EEPROM shown. The CS line on this must be taken high, or it'll draw a couple of mA.

I'm also worried at your nomenclature here. Have you got the EEPROM working?. You show the SO line on thisw, connecting to a pin you call SPISDO, and the SI going to SPISDI. You do realise that the SDO line on the master connects to the SDI line on the slave, and vice versa. If you have got the SDO to SDO, then this is potentially a clash, with two outputs trying to drive the same pin.....
ipq



Joined: 20 Aug 2015
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PostPosted: Tue Aug 30, 2016 2:58 am     Reply with quote
PCM programmer wrote:
What instrument are you using to measure the current ? Have you
checked the instrument with, say 3v running through a 1 MegOhm resistor ?


I'm using a multimeter UNI-T UT71C. I measured 3 volts using a programmable lab power supply and the result is 2.9 uA
ipq



Joined: 20 Aug 2015
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PostPosted: Tue Aug 30, 2016 3:00 am     Reply with quote
Ttelmah wrote:
And (of course), if the pins are not connected, what are you doing to stop them floating?. You do understand that a pin should not be left as an input, with nothing driving it, if you want low power?. If a pin 'floats' into the transition region, power consumption _will_ shoot up.

For low power design, every pin must be driven. Either externally with a circuit, or internally by switching it to being an output.

This also very much applies to the EEPROM shown. The CS line on this must be taken high, or it'll draw a couple of mA.

I'm also worried at your nomenclature here. Have you got the EEPROM working?. You show the SO line on thisw, connecting to a pin you call SPISDO, and the SI going to SPISDI. You do realise that the SDO line on the master connects to the SDI line on the slave, and vice versa. If you have got the SDO to SDO, then this is potentially a clash, with two outputs trying to drive the same pin.....


The spi port which drives the EEPROM is correctly connected. Right now there's no EEPROM since I removed it.
Ttelmah



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PostPosted: Tue Aug 30, 2016 4:16 am     Reply with quote
I thought you said it was drawing mA?.

2.9 uA

Given you are referring to having the secondary oscillator running, and I'm not sure from your current descriptions whether things like the brownout are enabled or not, this looks a totally sensible figure.
ipq



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PostPosted: Tue Aug 30, 2016 7:32 am     Reply with quote
Ttelmah wrote:
I thought you said it was drawing mA?.

2.9 uA

Given you are referring to having the secondary oscillator running, and I'm not sure from your current descriptions whether things like the brownout are enabled or not, this looks a totally sensible figure.


Sorry, it was a typing error. I meant 2.9mA.

Regarding the fuses, in the first post you can see all fuses set by code. The rest take the by default values.
Ttelmah



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PostPosted: Tue Aug 30, 2016 8:21 am     Reply with quote
OK. That is dangerous.

Look at the end of the list file, and see what the fuses are being set to. Never assume that these will be the values you want.

I'm very suspicious that you may well have the LCD charge pumps running (I found on another chip that they defaulted to running), so I'd start with a set of code that disables peripherals in turn and sees if the consumption drops.
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