I just received my NodeMCU, I have installed the CP210x driver. It shows up as: /dev/tty.SLAB_USBtoUART
This is under OSX 10.11.6.
However, I cannot upload any sketch via Arduino (I have installed the ESP community libraries). I cannot even get a response using esptool, for example if I try:
esptool.py -p /dev/tty.SLAB_USBtoUART -b 9600 read_flash_status
Then I just get "Connecting..." and nothing else happens. I am wondering if it is stuck in flash mode maybe? I don't know how to check this though or how to get it out if so. Or have I just been sold a bad device? Is there any way I can tell? I have tried two USB cables but I am not also powering the board with an external power supply. Could this be the issue?
Any advice would be great, I have plenty of experience with Arduino but completely new to the ESP.
Related
My employer has asked me to prepare for testing several thousand Chromebooks (mix of models/manufacturers) to refurb/flip. This may be a recurring thing.
Most or all of these will be old enough that CCD will not be available. I'd like to connect a widget such as a Raspberry Pi to the USB and have it automate testing as much as possible.
I know I can use keyboard emulation to inject commands, but I'd like to get a crosh session running over USB so that I can read info from the DUT besides just controlling it.
Google shows bazillions of returns about using a Chromebook as an ssh terminal but what I'm looking for is the opposite. I'm prepared for the answer to be a simple "no" but I'm concerned because I can't find that anyone else has asked this question. I don't think I'm that creative, so I suspect my Goog-fu is weak.
The answer appears to be "no". However I solved it another way; using "gadget mode" I have a Raspberry Pi ZW enumerate as a keyboard and a serial port. I put the Chromebook into Developer mode, open a developer shell with ctrl/alt/F2, or on a PC/linux or Mac system open a terminal window and type "sudo su" (these have to be done manually). Then I have the RPi issue this bash command to identify the serial port "in the blind":
SERPORT=/dev/serial/by-id/$(ls /dev/serial/by-id) # Chromebook or PC/linux
(or)
SERPORT=$(ls /dev/cu.usbmodem*) # Mac
Now I can have the RPi inject commands via the keyboard, put ">$SERPORT" on the end of each command, and the output comes in the RPi gadget serial port. The RPi then packages the data and forwards it over WiFi to our CRM. It's working nicely for Chromebooks, PCs booted into linux, Mac desktops and Macbooks.
Edit:
The company I work for has actually turned this into a product and so I'm not sure how much detail I should share, but...
I learned my way around gadget mode on the RPi from this link. There are examples for setting up a keyboard and a serial port. Using the templates in that link, I made a device called /dev/hidg0 which emits keyboard scancodes from the RPi to the Chromebook. I also made a device called /dev/ttyGS0 which the Chromebook sees as a serial port.
So I send keystrokes with some python like:
with open("/dev/hidg0","bw") as hid:
hid.write(blah)
and then have the Chromebook send text to the serial port, which I then read by looking at /dev/ttyGS0
Hopefully this will be enough to get you started. I found the isticktoit link very helpful.
I seem to have come across a strange issue. When my NodeMCU is connected onto a PCB circuit, I am unable to burn the program into it (even though the board is not powered up!). It says:
espcomm_open failed
espcomm_upload_mem failed
But the very same NodeMCU, when I pull it out of the circuit and try to upload the code works fine. Why is this?
P.S. Well, I can pull out the NodeMCU, burn the program and re-insert it, but I am trying to understand what's happening behind it.
I think your comm port is getting closed or used when you plug it into the pcb circuit. So the Arduino IDE cannot comunicate with the nodeMCU com port.
I had simmilar problems and after xxx attempts i uploaded it when the Nodemcu was unpluged from the PCB and worked perfectly.
I lately found out that the pcb used com port pin.
I have a esp dev board that I've been trying to get to work, but have faild miserably. after spending a few days trying I was able to 'flash' a firmware and up load code(to connect to my wifi) via arduino IDE. the problems are when I open the serial monitor the serial monitor window is nowhere to be seen(it refuses to show up on my desktop, but if I place my mouse over arduino IDE on the task bar I can see a tiny version of the window with what seems like the esp is supposed to tell me). I verified the wifi program was working with advanced ip scanner. The other problem is that when I try to use esplorer I am told the following:
Communication with MCU..Got answer! Communication with MCU established.
AutoDetect firmware...
Can't autodetect firmware, because proper answer not received (may be unknown firmware).
Please, reset module or continue.
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I've tried reseting via hardware and software and also saving a init.lua to the esp ( which I am told: Waiting answer from ESP - Timeout reached. Command aborted.)
Is there an easy step by step tutorial or something where I can get this thing to work in such a way that it is possible to develop with it? I dont care what language I have to use as long as I dont have to spend more time on trying to get the hardware to work. For something that is Arduino-like hardware it is significantly harder to do the simplest thing, a pic mcu is easier.es
If you are doing serious IoT thing then, I guess its better to go by Espressif IDE. There's a Freetos version also available which makes programming experience better.
To get started step by step you can check lot of videos on youtube, that's my preferred way of getting started. I found these three helpful to get started : here
I need to slow down (simulate bad) internet connection, I found some documentation where it was achieved by "ipfw pipe" command , the thing is that in latest MAC OS versions , ipfw was deprecated (and removed)...
I was wondering if there are any alternative to the ipfw API ?
Does anyone know how latest Network Link Conditioner achieves it?
The original previous way which enabled to slow down an internet connection :
sudo ipfw pipe 1 config bw 56Kbit/s delay 200 plr 0.2
and to clear the pipe :
sudo ipfw delete 1
Thanks.
I don't know much about Mac OS (I use Linux myself), but I'll give this a shot.
A bunch of digging established that ipfw seems unavailable, as you say.
I was also unable to find a way to use the Network Link Conditioner from the command line. Everything should be usable from the command line, so that's stupid.
One work around would be to try to access the NLC from within AppleScript. The following will get you started on toggling the NLC:
property thePane : "com.apple.Network-Link-Conditioner"
tell application "System Preferences"
activate
set the current pane to pane id thePane
--delay 2
end tell
---
tell application "System Events"
tell application process "System Preferences"
try
click ((checkboxes of window "Network Link Conditioner") whose description is "enable switch")
on error
click ((checkboxes of window "Network Link Conditioner") whose description is "enable switch")
end try
end tell
end tell
I think that you can run a script from the terminal with osascript <SCRIPT>.
As an alternative, Charles Proxy is a pay-to-use program that can be used to perform throttling, provided you can convince the software you are testing to connect to the proxy's port rather than directly to the internet. Maybe there are free proxy solutions out there somewhere?
Perhaps Squid would work in that regard. SquidMan seems to be an easy-ish way to install it for Mac. It looks as though DelayPools and or Client Bandwidth Limits might be useful for simulating a low speed connection, though I can't find evidence of people having used them for such.
I found several solutions that might work. They come from some old threads, but they might help:
How to simulate slow internet connections on the mac
Apple has made a very handy official tool to slow down the network connections on you Mac for testing purposes.
The Network Link Conditioner preference is a free download from within Xcode (for Lion and later OS). Additionally, iOS has similar function accessible from within Xcode and iOS 6 or later.
How do I simulate a bad Wi-Fi connection on my iPad?
There are a few ways you can do this, depending on your situation:
Move further away from your router. While this may seem a bit obvious, I realize that it isn't always possible while testing/debugging (for example, if you are working on a desktop computer).
Put aluminum foil around the router and/or antenna. This will (partially) block some or all of the radio signals by creating a makeshift Faraday cage. The results you get will depend on the strength of your router signal, distance from the router, and other environmental factors.
Set your router's wireless signal power to a lower setting. The method for doing this is different for each router, so you will have to look at the user guide for instructions on how to do this.
Slow down internet for iOS simulator
You can set the network to slow characteristic by testing on devices. Go to Settings -> Developer Settings -> Network Link Conditioner -> Enable. This is for iPhone/iPad running iOS 6
I don't know if the last one you can still do.
I've used many methods in the past for slowing down network connections, among them:
performing a parallel download of some massive Linux ISO file;
physically pulling out the Ethernet cable (at one point, I actually toyed with the idea of building a push-button device that would sit between two cat5 cables and do this without having to physically disconnect the whole cable).
using ifconfig eth0 down ; sleep 1 ; ifconfig eth0 up.
Hopefully one or more of those methods will help.
If you're looking to slow down your network connection because you're doing testing/profiling work, one option is to get a specific device that can create network latency/noise.
For example Apposite Tech's mini2 WAN emulator allows you to change values for bandwidth and packet loss. You can roll your own device too using something like: http://wanem.sourceforge.net/ . It just depends on your needs, time and budget.
I am working in a technology Laboratory. We have 15 BBB, an suddenly, 5 of them didn't power on any more.
They stay with the power on Led on, but nothing more happens.
Picture:
What can i solve the problem?
Thank you
Prior to solve the problem, you probably have to investigate it first.
I would verify those beaglebones are still functional:
That is, checking if the beaglebone black is displaying any messages on the serial console,
The procedure for connecting a USB-to-TTL adapter is described here.
I would strongly suggest to buy the exact adapter featured in the article above on e-bay
if you don't have one.
If there were no messages displayed on the serial console, I would attempt to load u-boot from the serial port.
This can be done by connecting both P8.44/SYS_BOOT3/LCD_DATA3/GPIO2_9
and P8.43/SYS_BOOT2/LCD_DATA2/GPIO2_8 to the ground (two of P9.43/P9.44/P9.45/P9.46) using two 4.7 k
ohm resistors, powering the beaglebone with an external 5V power supply (not by USB),
and power-cycling the beaglebone - power-cycling IS required, performing a 'reset' is
not enough for the new SYSBOOT configuration to be taken into account.
You can then download u-boot from your PC using Teraterm: u-boot-spl-.bin should
be downloaded using x-modem, and u-boot.bin using y-modem, as described in the
'Boot over UART' section of this TI wiki article.
Once you have u-boot running, you should be able to reinstall your beaglebone using information available on the Internet.
If you cannot boot using the boot ROM and the serial port, this would probably be a bad sign.
I would suggest to try the procedure for loading u-boot from the serial port with a beaglebone you know is working, this is totally non-intrusive providing that you don't modify the eMMC from u-boot.