331–340 of 521 posts
I just bought 2 magpi to get 2 raspiberry pi zero but connecting then to a android charger (without and with sdcard http://director.downloads.raspberrypi.org/raspbian_lite/imag... ) none of then lights the green led to indicate power on. Someone have a different experience or can tell something about this ?
I just bought 2 magpi to get 2 raspiberry pi zero but connecting then to a android charger (without and with sdcard http://director.downloads.raspberrypi.org/raspbian_lite/imag... ) none of then lights the green led to indicate power on. Someone have a different experience or can tell something about this ?
Make sure you are connecting the 5V power supply to the PWR IN port, not the USB port.
Can someone tell if only connecting the power supply would light the green led (no sdcard) ?
LCD screens are like, $100, a mouse is $10-$20 new and low-end keyboards are $10-$30. At that combined price, why does it matter if the computer is $25 or $5?
And if one is going to outlay the 150 bucks in peripherals, they might as well spend a bit more than $5 on the computer to get a significantly better computing experience.
Is there anything else going on here? Do they have a different approach that I'm not getting? It feels like, yeah, Moore's law is great and computers are cheap, but once RPi got to around or <$50 (which it did with the first version anyway), the computer was already cheaper than everything you needed to plug in to it.
Earlier quoted context omitted.
standalone :) some inspirations for you http://hackaday.com/2015/09/05/esp8266-web-server-farm/ http://www.instructables.com/id/ESP8266-Wifi-Temperature-Log... If you end up working on it, feel free drop me an email, I'm really curious about the result :)
ok, thanks :)
I've looked at a few "Instructables" articles on ESP8266 and Arduino, and a large fraction of them seem to have this issue.
Another issue many of them that use a 5V Arduino have is that they ignore the difference between the logic levels of the 5V Arduino and the 3.3V ESP8266. For the connection from the ESP8266 UART Tx to the Arduino Rx, that's probably fine. The ESP8266 will drive the line to 3.3v, and that is high enough for the Arduino to recognize it as high on the Rx line, as long as you are powering the Arduino through the USB port or through the barrel jack (I'm using Arduino Uno for my examples, so some adjustment may be needed for other models).
If you are powering through the 5V pin, which bypasses the 5V regulator on the Arduino, then you could have a problem if your voltage is high. The minimum voltage seen as a logic 1 on the input pins goes up as supply voltage goes up, and since you are already near the edge when hooking an 3.3V ESP8266 up directly, you have to be careful.
For the connection the other way, Arduino UART Tx to ESP8266 UART Rx, you are putting a 5V signal on a pin that's supposed to only take up to 3.3V. The ESP8266 has built-in protection against over-voltage which probably will save you, but this is not good practice.
Simplest fix here is to use a 1k and 2k resistor to make a voltage divider for the Arduino Tx -> ESP8266 Rx signal. Note that this only works for going from the higher voltage side to the lower voltage side. That's fine here, since on the Tx->Rx connection only the Tx side drives the line.
If you have to hook different voltage I/O pins together and both sides can drive, you need something more elaborate. There's a cool solution that uses two resistors and a MOSFET. That, and some others, is given here [1].
[1] http://electronics.stackexchange.com/questions/97889/is-ther...
This is great, but for people who want to "get started in computing", don't they also need a display, a mouse and a keyboard? LCD screens are like, $100, a mouse is $10-$20 new and low-end keyboards are $10-$30. At that combined price, why does it matter if the computer is $25 or $5? And if one is going to outlay the 150 bucks in peripherals, they might as well spend a bit more than $5 on the computer to get a signif…
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Agreed for a supercomputer design it would be awful, but for a stereotypical 99.9999% CPU idle applications, the big win would be total cost of ownership / capex. On a long term view from many decades of observation, the digital world is bifurcating into one world thats 100% utilized all the time in data centers or real time control or video gaming, and another world that's 99.999% idle but when its active the users…
Most of this is the case for using one Pi, but not a stack of Pies. Unless you have some sort of micro-AWS which turns off the 99% unused ones. Ten boards drawing 100mW at idle are the same as one board drawing 1W at idle.
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I guess it would be harder to power an USB WiFi adapter. And it's not going to be cheaper than ESP2866.
Actually a 802.11n USB adapter costs $1.55, that's cheaper than a ESP8266.
This is great, but for people who want to "get started in computing", don't they also need a display, a mouse and a keyboard? LCD screens are like, $100, a mouse is $10-$20 new and low-end keyboards are $10-$30. At that combined price, why does it matter if the computer is $25 or $5? And if one is going to outlay the 150 bucks in peripherals, they might as well spend a bit more than $5 on the computer to get a signif…
Maybe it also makes it easier to do more daring things with it? it it breaks it's only $5.
This is great, but for people who want to "get started in computing", don't they also need a display, a mouse and a keyboard? LCD screens are like, $100, a mouse is $10-$20 new and low-end keyboards are $10-$30. At that combined price, why does it matter if the computer is $25 or $5? And if one is going to outlay the 150 bucks in peripherals, they might as well spend a bit more than $5 on the computer to get a signif…
On the flip side, I don't need a screen for all my computers. Some are network devices now (SSH only) and some share the same screen because I use them for different things at different times.
This is great, but for people who want to "get started in computing", don't they also need a display, a mouse and a keyboard? LCD screens are like, $100, a mouse is $10-$20 new and low-end keyboards are $10-$30. At that combined price, why does it matter if the computer is $25 or $5? And if one is going to outlay the 150 bucks in peripherals, they might as well spend a bit more than $5 on the computer to get a signif…
The use cases for such a device go as far as one's imagination.