Parallel Bank Monitor

[boB]

Would love to see a picture of the actual capacitors !

[Barry Fields]

Difficult to photo, but it is possible that I read them in error. Would 3.3k uf each make more sense. they are approx 4inch high and 1.25 inch diameter.

[Barry Fields]

I know you have many things to contemplate and I do not want to consume too much of your time.
Final comments.

Would your sampling issues improve if the WhizBang had it's own power supply. See attached.

Could the AUX2 negative port be configured as either UART TX or PWM out in the present or future version of the Classic 150?

[boB]

I know you have many things to contemplate and I do not want to consume too much of your time.
Final comments.

Would your sampling issues improve if the WhizBang had it's own power supply. See attached.

Could the AUX2 negative port be configured as either UART TX or PWM out in the present or future version of the Classic 150?

We use a similar MPS buck converter chip in another product now.  A bit lower input voltage and higher output current though.  Nice parts !

The AUX2 output already has PWM for different functions.

No, another power supply wouldn't help the sample rate and what we use could actually sample 1/3 faster than it already is sampling but that's not going to help much. 

Higher than 16 bit resolution would be nice but it would have to be biased to read greater than +/-15 bits for charge and discharge as well as self zero-offset correction between samples.  And low power.

boB

[Barry Fields]

The AUX2 output already has PWM for different functions.

I know PWM is available on the AUX2 positive. Is the AUX2 negative port merely a ground or is it configurable ?

[boB]

The AUX2 output already has PWM for different functions.

I know PWM is available on the AUX2 positive. Is the AUX2 negative port merely a ground or is it configurable ?

Oh, I see.  Negative is same as battery negative.

AUX 1 can be isolated by the small relay if jumpered correctly.

[Barry Fields]

I have to admit I have learned much since engaging on this forum. I feel I have left the 1980's and have arrived in the 2000's (maybe).
I am trying to learn more about ADCs.
Does the shunt mv input to the ADC need amplification first?
I believe it was stated that 1bit of the serial out put of the ADC is  used to indicate charge or discharge.
In a 4 analog input ADC, does the identity of the input require additional hand shaking or could 2bits of the serial output be used for that purpose?
If 3bits are used above would that leave 21 bits of signal resolution on a 24 bit ADC?
I have tried to read the data sheet on the LPC2366 MCU and am unsure whether the UART input you are using can handle a 32bit input. It looks like it but I have been wrong before.
Can I ask what ADC you are using?

[boB]

The ADS122U04  looks like a very nice part but kind of expensive. It might be OK when bought for production though...   The ADS122U04  is only good for 20 bits of resolution the data sheet says.  This is the case for many 24 bit ADCs except maybe for the best audio ADCs which might be good for 21 bits ?  I haven't looked lately.

No amplification used.

The UART is good for 7,8 or 9 bits.  This is typically the case for UARTs.  If you need 24 or 32 bits, then maybe an SPI port could be used ?

You would have to look up 16 bit ADCs in a SOT23-5  pin configuration.  Microchip and TI make them.

Oh, the most significant bit, bit 15  would be a sign bit so basically 1 for negative current.

boB

[Barry Fields]

Maybe another dumb question. Am I correct that the Classic's USB port is only used for firmware updates?

Could it also be used the rest of the time as a WhizBang input?

[boB]

USB is mainly for updates but it also spits out data.

Not good for a WB Jr. though as the WB Jr. isn't a USB device

boB

[Barry Fields]

Does the USB TX data only during update or is it also connected elsewhere?

Could a WB Sr be a USB device?

[Barry Fields]

WB Sr ?
32bit 4channel to SPI    AD7177-2
SPI to USB               FT232H

[boB]

WB Sr ?
32bit 4channel to SPI    AD7177-2
SPI to USB               FT232H

Performance specifications :

19.1 noise free bits at 10 kSPS
20.2 noise free bits at 2.5 kSPS
24.6 noise free bits at 5 SPS



It might be good for 22 to 23 bits at at our 10 SPS speed.

$20+ dollars each at high quantities.

I could work but won't be replacing anything soon.

Thanks !

boB

[Barry Fields]

Just trying to think outside the box. Thanks for your time.

[boB]

Just trying to think outside the box. Thanks for your time.

No problem !    This part would actually work very nicely.  Like, 26 bits of resolution at 15 samples per second.

Now, the question is, can it run biased in the middle so it could work at +/- 24  bits per sample ?  That would be nice.

There may be other A/Ds too.  If you find others, lettuce know.

boB