What it's all about
I am planning to build this Low Energy IOT Door Sensor. The idea is to stick it in a professor's door to see when he's available. (It's an issue waiting outside his door all the time.)
I think I can set up another ESP8266 to receive the signal, and log the data with an Arduino. Besides the questions below, I'd appreciate any pointers on the device-to-device communication and data logging. I plan to work that out when building/experimenting with my little experience with ESP8266 and NodeRED hoopla. I'm also just doing this for the learning experience, but it'd be better if the actual application is fruitful.
Brass tacks
The main thing I want to understand is the low dropout (LDO) linear voltage regulator. It seems that the $1.14 AMS1117 is what people are using. But then I find this 38 cent AP7370. I wonder about the difference in specs:
Voltage Dropout (Max) 1.2V @ 800mA 0.6V @ 100mA
Current - Output 800mA 300mA
Current - Quiescent (Iq) 5mA 2.5µA
Current - Supply (Max) 10mA 300µA
So I read these pages:
Will that four-terminal node in the circuit go over 300mA?
Calculated as 3.3/(110k) or how can that node be analyzed?
Also, the maximum current drawn from a GPIO pin is 12mA (for the ESP8266-01). Would that change.....
Mostly, how much current will the circuit draw?
It's from a $8.88 ~100 mAh battery on Amazon: 4.2 V when completely charged to 3.7 V.
TMI
Before I wandered across the Instructable above, I was looking into creating a continuity tester, transmitter and receiver using the Beetle (smallest Arduino). The thought was to have the door's metal plate complete the circuit (continuity), log the data, then send the signal. This way a sleep mode could be used...
I am planning to build this Low Energy IOT Door Sensor. The idea is to stick it in a professor's door to see when he's available. (It's an issue waiting outside his door all the time.)
I think I can set up another ESP8266 to receive the signal, and log the data with an Arduino. Besides the questions below, I'd appreciate any pointers on the device-to-device communication and data logging. I plan to work that out when building/experimenting with my little experience with ESP8266 and NodeRED hoopla. I'm also just doing this for the learning experience, but it'd be better if the actual application is fruitful.
Brass tacks
The main thing I want to understand is the low dropout (LDO) linear voltage regulator. It seems that the $1.14 AMS1117 is what people are using. But then I find this 38 cent AP7370. I wonder about the difference in specs:
LM1117 AP7370
Current - Output 800mA 300mA
Current - Quiescent (Iq) 5mA 2.5µA
Current - Supply (Max) 10mA 300µA
So I read these pages:
- https://www.vidatronic.com/5-basic-...when-selecting-an-ldo-for-your-system-design/
- https://www.richtek.com/selection-guide/en/selection-ldo-criteria.html
- https://www.allaboutcircuits.com/technical-articles/choosing-the-right-ldo-beyond-the-basic-specs/
Voltage Dropout (Max)
The LM1117 is just over a volt at 100mA. So the AP7370 is better, "the smaller the dropout voltage, the greater the useful input voltage from the battery and therefore the longer the run time." [1] Defined, "voltage drop across the regulator where the device can no longer regulate the output voltage." [2]Current - Output
The LM1117 has a higher maximum it can provide. Will that four-terminal node in the circuit go over 300mA?
Calculated as 3.3/(110k) or how can that node be analyzed?
Also, the maximum current drawn from a GPIO pin is 12mA (for the ESP8266-01). Would that change.....
Mostly, how much current will the circuit draw?
Current - Quiescent (Iq)
Less is better: "current consumed by the regulator when it is not supplying load current." [3] The AP7370 wins.Current - Supply (Max)
Maximum current supplied by the battery? Is there a way to test this?It's from a $8.88 ~100 mAh battery on Amazon: 4.2 V when completely charged to 3.7 V.
TMI
Before I wandered across the Instructable above, I was looking into creating a continuity tester, transmitter and receiver using the Beetle (smallest Arduino). The thought was to have the door's metal plate complete the circuit (continuity), log the data, then send the signal. This way a sleep mode could be used...