NodeMCU and HX711 using ESPlorer - lua

I don't know if his is the correct topic to ask this but here it goes:
I have a NodeMCU devkit 0.9 and I'm am able to use ESPlorer to upload basic code like the web server with some buttons that turn on and off LEDs on the board.
I was trying to interface NodeMCU with a load cell amplifier (HX711), which I saw has libraries for NodeMCU. How can I "include" hx711.c in my .lua file for it to recognize the functions inside hx711.c?
The error that appears when I try to send to ESP is
LUA interpreter error detected
stdin:1: attempt to index global 'hx711' (a nil value)..."
Best regards.

You need to build a NodeMCU firmware that includes the HX711 module. Then you need to flash the new firmware to your devkit.

Related

Unable to load Lua Scripts to NodeMCU: Invalid node.chipid()

For all of these scenarios, I am able to upload the firmware and monitor via serial usb. But after creating my first firmware, for all new firmware, I can't upload Lua scripts using the nodemcu-tool without getting the following:
Error Message
F:\Development\NodeMCU\helloworld>nodemcu-tool -p COM3 upload init.lua
[NodeMCU-Tool]~ Unable to establish connection
[NodeMCU-Tool]~ Invalid node.chipid() Response: 6935962
Observations
Can reset the board using nodemcu-tool. Leads me to assume the baud rate is fine.
Can see the file system being created from PuTTy after loading any of the firmware. Leads me to assume the firmware is OK.
Have tried multiple dev boards, same results
Found the source of the error message device-info.js. either line 45 or 49
I have no idea what "Response: 6935962" means. Is that my chip id or an error code?
A new commit was made to the firmware source during the last couple of days. No idea if this is relevant.
Was hoping to get this resolved before I go down the Docker rabbit hole. Lazy. I know.
9/6/2019 - created first firmware to start development
Built a firmware using https://nodemcu-build.com/ with these modules (cron, file, gpio, i2c, mdns, mqtt, net, node, sjson, tmr, uart, wifi)
Uploaded the firmare using NodeMCU-PyFlasher-4.0
No issues with this firmware. I've been able to upload lua scripts and test them successfully. Even now, I can revert back to this firmware and use it without issues. I've even redownloaded this firmware from the original link, and it works fine.
9/7/2019 - created a new firmware to use adc and other goodies
Built a firmware using https://nodemcu-build.com/ with these modules (adc, cron, file, gpio, i2c, mdns, mqtt, net, node, rtctime, sjson, tmr, uart, wifi)
Uploaded the firmare using NodeMCU-PyFlasher-4.0
Having the problem described above.
9/8/2019 - built firmware with minimal modules
Built a firmware using https://nodemcu-build.com/ with these modules (file, gpio, net, node, tmr, uart, wifi)
Uploaded the firmare using NodeMCU-PyFlasher-4.0
Having the problem described above.
Platform & Tools
Windows 10
Development board: HiLetgo ESP8266 NodeMCU LUA CP2102 ESP-12E Internet WiFi Development Board Open Source Serial Wireless Module
Firmware builder: https://nodemcu-build.com/
Serial Monitor: PuTTy 0.72
Firmware Loader: NodeMCUPyFlasher 4.0
Lua script loader: nodemcu-tool 3.0.2
fetchDeviceInfo() first calls node.info() at https://github.com/AndiDittrich/NodeMCU-Tool/blob/master/lib/connector/device-info.js#L9. Then it does an if-else to figure out whether it's running on ESP8266 or ESP32.
With the recent upgrade to SDK 3.0 node.info() was changed in PR #2830. See documentation at https://nodemcu.readthedocs.io/en/latest/modules/node/#nodeinfo. It now returns values the script doesn't consider to be coming from ESP8266. The script then calls node.chipId() in the else branch. So, it's getting a chip id from ESP8266 but it is expecting one from ESP32. Hence, the exception.
I have no idea what "Response: 6935962" means. Is that my chip id or an error code?
It's your chip id.
To cut a long story short: NodeMCU-Tool needs to be adjusted as laid out above to work with the current NodeMCU version.
I cached the same issue from the recent cloud build(https://nodemcu-build.com/). It works when i switch back to the old ones. It looks like a problem of the build system or recent source code. You can switch to other build method and try use the older code.

NodeMCU module enduser_setup: Program does not compile

I built NodeMCU firmware with module enduser_setup, but when using it in Arduino IDE the compilation stops with this error:
enter code here test_:35: error: 'enduser_setup' was not declared in this scope`
Do I need to include something else?
There seems to be a fundamental misunderstanding. There are two choices but you mixed and matched them.
If you want to program the Arduino way then you don't need the NodeMCU firmware. You have to be prepared to compile and upload the entire binary to the device every time you change a single bit in your program.
If you want to program in Lua, a scripting language not too different from JavaScript, then you need to flash the NodeMCU firmware first. After that you simply upload your Lua script(s) and (re)start the execution or invoke the new functions you just uploaded. You won't need the Arduino IDE at all for this.
Disclaimer: I'm a member of the NodeMCU firmware team and thus I can't deny being slightly biased as to which approach I prefer.

ESP8266 - Is it possible to just run Lua from C (not the full NodeMCU environment)?

I'm working with ESP8266 and I don't want to use Lua for the whole project, I just want to run a few snippets of Lua code, received from wifi/sd card. I'd need to start a Lua environment and run the scripts, which would then eventually call some native functions for low level tasks. In other words, I just want to use Lua as simple scripting language (as it's intended to be) to implement some dynamic behavior. Is it possible? Is there any build of lualib for arduino?
Thanks in advance!
You can simply embed Lua in a extlibs/ folder for example and link to it when compiling your program.
There is existing Lua binaries but building it yourself is easy and better (as it's multiplatform).
OK, I know both answers told me I can just embed the code into my project, however, I found out I need to make some small changes. I made an example working project available here and the following list of changes had to be made:
The flags LUA_32BITS and LUA_USE_LONGJMP (C exception handling) were enabled
The following libraries were excluded: io, os, package, coroutine
The following functions were removed from C API: luaL_fileresult, luaL_execresult, luaL_loadfile, luaL_loadfilex, luaL_dofile, luaB_loadfile, luaB_dofile
Lua output messages are redirected to the Serial interface, check tinylua.h, tinylua.cpp and lauxlib.h to change this behavior
Hope this helps!
The ESP8266 has up to 4MB of program storage. Theoretically you can get up to 16MB as the datasheet specifies.
As I remember, compiling an amalgamated version of Lua (all sources in one file), occupies less than 100kb.
So, you can compile the Lua library and use it as needed on esp8266, even using Arduino IDE.
But you will get NAKED Lua if you do so... No nifty libraries to control Wifi, serial, SD, ports... You would have to provide that in C, or use NodeMCU code as you need.
You can try LuaJIT and access C code directly from Lua, cutting out the need for writing libraries. I have no idea of how you would compile it to Esp8266, or if anyone have tried this before, but you can do it "for science" and tell us how it turned out.

Lua debug on an embedded ARM based platform

I am new to Lua. I have an ARM Cortex based product with an OS providing TCP stack, SD card for file storage, and lots of custom hardware. I have embedded Lua (from the standard source distribution) into the product and added an API to give Lua access to my hardware. Also have Telnet and FTP services running. Works great.
Now I would like to add the ability to debug scripts with ZeroBrane. Looks like I need to add MobDebug, and connect it to my OS thru LuaSockets. Assuming this is a valid approach, can anybody point to a tutorial or documentation that would help?
Thanks
Assuming you have access to luasocket on that platform, you can follow the instructions on remote debugging with MobDebug and ZeroBrane Studio. It should be a matter of adding require('mobdebug').start('IP-of-computer-running-ZeroBraneStudio') and making project files available in ZeroBrane Studio.
ZeroBrane Studio also does mapping between different file systems to allow debugging of scripts running on one platform from the IDE running on a (possibly) different platform. You only need to make sure you have the same project structure. For example, you may have /usr/me/myprojects/projectA/fileB.lua and start debugging of projectA/fileB.lua in /usr/me/myprojects/; then on the IDE side you may have D:\Users\Me\myprojects\projectA\fileB.lua opened in the IDE and it will attempt to map /usr/me/myprojects/ to D:\Users\Me\myprojects\. If you run into issues, you can use IRC or the maillist to get further help.

What opensource tools are available for writing in actionscript

Basically I want to make a simple flash application that will take a stream from my webcam and broadcast it over an rtmp server. I know absolutely 0 actionscript at this point. Before I get into learning I need to know what opensource tools are available. I've downloaded mstasc, but I'm having trouble using it. I made a simple script that does nothing but set a variable (var test="test") but this gives me errors (characters 0-3 : parse error Unexpected var)
any advice?
FlashDevelop is a nice open source IDE, but it's Windows only. You've found the Flex SDK haven't you?

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