23
votes
Accepted
ESP8266 eLUA (NodeMCU) vs MicroPython
Here's a slightly different approach in stead of a Lua vs. Python shootout:
Six of the most popular ESP8266 "runtimes":
AT Command SET. Popular when the 8266 is paired with another MCU.
Communicates ...
- 1,820
9
votes
Accepted
Why am I detecting two I2C addresses on the same board, and why do neither of them appear in the datasheet?
The I2CADDR pins are used to set the address of the device.
Some of the bits in the I2C address are not selectable. Those are the 4 MSBs. The 3 LSBs in the address are selectable by HW. The address is ...
- 441
8
votes
How to free up memory in a CircuitPython board?
I love Python. Most of the programs I write for my own use on my PC at home are written in Python.
That said, I don't use Python in my microcontroller based projects.
Python is intended for use ...
- 69.1k
6
votes
ESP8266-12E MicroPython Unable to access REPL (Python prompt)
I was having a similar problem with a Wemos D1 mini board. Erasing and Flashing the firmware worked. However I was getting no REPL prompt, resetting was giving me garbage. I solved it by adding "-fm ...
- 61
6
votes
Is there a spice directive to export waveform data in LTspice?
I'm sorry to necromance, but you can run LTspice with:
scad3.exe -ascii -b netlist.net
And it'll give you an ascii file output. You can combine this with the <...
6
votes
Why am I detecting two I2C addresses on the same board, and why do neither of them appear in the datasheet?
Both two addresses do match the addresses listed in the datasheet.
Even the address configuration pins look like they are working.
The I2C pins do have pull-ups. You need to look at the schematic of ...
- 137k
6
votes
Accepted
How does LTSpice solver know the type of the component?
It knows that R1 is a resistor because it starts with an R.
It knows that C1 is a capacitor because it starts with a C.
This is integral to how SPICE works; what type of component something is is ...
- 30.3k
5
votes
FFT of a square wave
I'd make this a comment, but I don't have enough points to do that yet.
You should plot your FFT data starting at 0 Hz and go up to, say, 500 Hz. That will give you 10 or so harmonics. You are ...
- 91
5
votes
Accepted
FFT of a square wave
Your signal is a square wave with its base at 0V and its peak at 2.7V or so. So it has an average voltage of 1.35V. In the frequency domain, the overall average of a signal is its content at DC or ...
- 45.4k
5
votes
Accepted
How to find out the used code?
Your original sample is too small to know if it's FLAC or not. You need a long sample, and then look for 0xff 0xf8 bytes in it to see if you have FLAC block ...
- 13.2k
5
votes
Accepted
Bipolar stepper motor spins very slowly and makes a loud noise
Check with a multimeter that red-yellow is one coil and blue-orange is the other.
The chart shows that you've got to start the stepper at about 500 Hz and ramp up. Starting at too high a frequency ...
- 171k
5
votes
Accepted
Interacting with SPICE netlists using PySpice
This first one is not a SPICE netlist; it looks like it's typical for the ExpressPCB program. The one after the edit is a SPICE netlist. The general notation for the elements is this:
The first ...
- 21.2k
5
votes
Accepted
Interfacing an old spectrometer with PySerial
Note that your device has non-standard wiring, as pointed out in comments, and in particular the signal ground. You'll have to ensure you have the three wires connected between your device and your ...
- 13.2k
4
votes
Accepted
How to hook Raspberry Pi with Electret Microphone to detect sound levels in dB?
You selected a microphone board with automatic-gain. This is exactly the OPPOSITE of what you need. You can not measure the actual audio levels when there is something upstream UN-doing all the audio ...
- 14.4k
4
votes
What effect does the frequency have in PWM?
To a first approximation, frequency does not matter at all, provided it's fast enough to avoid the appearance of blinking. All that's important is the average power of the LED, which depends only on ...
- 57k
4
votes
LTspice automation
Have you tried "LTSpice Queue Manager"? (The link redirects to my own website where you can download the software but I'm not its author, who originally shared the program on a forum that is ...
- 111
4
votes
Laplace transform on simple low pass filter in Python
You're trying to plot in the time domain (ie. the x-axis is in seconds) but your formula is in the frequency domain (s is a complex frequency variable). You would ...
- 3,201
4
votes
Python to trigger USB square wave pulse for camera
Python has a library for nearly everything:
From xkcd.
It unfortunately does not include a module for "make USB do things it wasn't built to do."
You can't send single pulses over USB. It ...
- 69.1k
4
votes
Accepted
Using Python to simulate an LTspice netlist
Errrm.
What's unclear about the examples on the Python ltspice library page?
Example circuit:
Example code:
...
- 69.1k
4
votes
Accepted
RPi Pico not reading a button correctly
If you don't have an external pull-down resistor on the input pin, enable the internal pull-down.
- 137k
4
votes
Why am I detecting two I2C addresses on the same board, and why do neither of them appear in the datasheet?
They both look like the addresses in the datasheet. Page 10 says the addresses are 0101 0XXXb and 0101 1XXXb, the X values depend on the address configured using the I2CADDR, which you can apparenlty ...
- 4,096
4
votes
Accepted
voltage divider using skrf
You believed that you're simulating this circuit - a voltage divider connected to an ideal voltage source (zero output impedance) at one side, and to an ideal voltmeter (infinite input impedance) at ...
- 6,409
4
votes
Accepted
JFET Id calculation mismatch in SPICE
The 0.5 factor should not be there in your calculation. See 3-22 page 143 of 2nd edition Semiconductor Device Modeling With Spice (Guiseppe et al.) which is the same equation as you have but the 0.5 ...
- 384k
3
votes
Laplace transform on simple low pass filter in Python
Your voltage is given in the time domain (voltage values as function of time \$t\$).
Your low pass filter definition is given in the s-domain (transfer function as function of complex frequency \$s\$)...
- 16.2k
3
votes
Accepted
Am I using Shannon-Hartley Theorem and thermal noise correctly here?
Looks reasonable to me.
Dont forget that you are calculating the maximum possible THEORETICAL performance for that channel assuming it is in fact thermal noise limited, at VHF and up that is not ...
- 17.4k
3
votes
How to hook Raspberry Pi with Electret Microphone to detect sound levels in dB?
You have the wrong thing, first off
The automatic gain control (AGC) on your existing microphone-board is not what you want here -- a sound level detector is going to get thrown off by the action of ...
- 8,888
3
votes
Microcontroller and SDRAM
You could get a Raspberry Pi. That would simplify a lot of things that you want to achieve.
3
votes
3
votes
start a LTSpice simulation using code in MacOS
I'm maybe a little too late for the party, but after reading the above, and having a similar problem I found that the package content of the LTspice app has an executable file found at:
...
- 31
3
votes
Pyserial doesn't read entire line
PySerial (and serial libraries in general) have no idea of the concept of a "line".
When you port.read(), you get what is in the serial buffer right then, so if ...
- 32.1k
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