1. You are right, it should be project/board specific, you can assign that pin properly based on your hardware, the desciption in the project doc is based on the PSoC4 BLE kit.
2. You may just directly use it with CYBLE-22411-00, I remember the ADC of the two chips(the one used in the original project and the CYBLE-22411-00) is same.
3. I think these values apply to CR2032.
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3. The "percent battery charge" is based on the expected SoC for each voltage level for the CR2033 lithium battery. Unless it has different voltage ratings (I can't find the datasheet for the CR2033), then similar voltage and type of battery with only a small difference in the amount of total charge it stores should have a similar SoC to voltage correlation, which means that it should work. Basically, the percentage battery life is estimated from the voltage for the type of battery, and similar batteries will have a similar estimation.
Where can I find information what pin to use? I could not find it in the CYBLE-224110-00 data sheet
The Pin P3 looks fine when I build your project; Are you expecting a certain pin for use by the ADC to get the Vref?
The example project shows an external Capacitor wired to the Vref pin. If you are wanting to measure the battery voltage without external components, then see here: http://www.cypress.com/blog/psoc-hacker-blog/measuring-vdd-battery-volts-psoc4
(If you directly reference the Vref, then on a comparison between battery voltage and the Vref, it will almost always come back with 100/100%)
I'm a bit confused with the terminology. By "external" do you mean a physical part that has to be connected to the PSoC ? Or is it a logical component? I started reading the article you mentioned and the same question applies. Thank you
When documentation for the PSoC chips uses "external" they generally mean a part or component that is NOT inside of the CYBLE module, or whatever chip you are using, and thus it would be a component that you need to wire to the pins on the cypress module using one of the IO pins, PCB traces, jumper wires, etc.
When they refer to "internal" they are generally referring to something already included, and within the cypress module/chip.
For example, the ADC itself is internal to the cypress module, but the pin it reads from can be external.
In the top design schematics on PSoC schematics, the blue "penned" looking wires, resistors, capacitors, etc. all refer to documentation on externally wired components for the project. Thus, the article referenced is using an external resistor divider bridge to read the ADC values from. That means, that you would need to dedicate a pin for the use of measuring battery voltage level.
Tl;Dr; Yes, external means a physical part that needs to be connected/wired to the PSoC.
Thank you for clarifying, this is very helpful. I'm looking for a solution that does not require any external parts. Is there such a solution?
Not as far as I know, but someone else would probably know better.
Support for an internal VDD battery measurement with the ADC would require a different chip, or manufacturing changes afaik.
Sorry, but good luck
Even more confused.
"We can implement the same VDD measurement in PSoC4 without using any external components. Let us see how.
Note: The resistor and zener combination in the schematic above is just a representation of an external reference voltage."
This implies that no external parts are needed and everything can be set up in PSoC Creator
But then it says
"Following are the steps to measure VDD:
Connect an external bypass capacitor 1uF to P1."
Which implies that an external part IS needed.
Could you please clarify?
Yeah, hence why I was thinking there is not a good way to measure it without external components. It could be that he is using the OpAmp buffer as replacement for the capacitor to hold the reference voltage for measuring, but without running it, I would not be confident in that. He also still refers to the P1 pin in his firmware code below it, so either that pin is used to get the internal reference voltage of 1.024 volts, or he really is using the external capacitor. :/
I would recommend testing with the OpAmp buffer to see if it replaces the capacitor behavior, but otherwise I don't know
The article is very confusing. In one sentence it says that on MCU's with internal ADC the measurement can be done without any external components , in the other says that it is required.
Can anyone clarify?
If an external bypass cap is indeed required on CYBLE 224110 , what pin should it be wired to ? There is no P1.7 that the article refers to on the 224110
Personally, we used the resistor divider to get the battery voltage reference, and compared it with the internal 1.024V reference on the ADC to get our own battery reading, but that is using external components...
If using external components is a requirement that's ok. But it 's still unclear to me which pin of the CYBLE the external component should be wired to. I don't see P1.7 mentioned in the article in the CYBLE-22110-00 project "Pins" section
I think the intent of the article, is to use the OpAmp to buffer the battery voltage as an "internal capacitor", and then to switch the ADC to use the internal 1.024V reference to calculate the voltage from the OpAmp "capacitor" for measuring the battery voltage. I'm not seeing the P1 for the CYBLE-224110-00 device either, but it could be the exact pin doesn't matter?
I tried to mimic/build the project in the article to help you out, but I don't have the board with me to test if it works.
I think, using the internal OpAmp allows you to not need to use an external component; The pin that the board uses for the voltage reference buffering will be in use however.