Category Archives: Programming

Computer and micro controller programming in a variety of different languages utilising many frameworks including Kohana, jQuery and CodeIgnitor

New ESP32 WeMos Module

I ordered an ESP32 module from Ebay:

http://www.ebay.co.uk/itm/WeMos-D1-Mini-Mini-Pro-Compatible-Shields-Now-with-Triple-Base-and-ESP32-/322729576423?var=&hash=item4b242e87e7:m:mTDnl7ewzGuk9vFvBSGmXCA

The pinout for the board is shown here:

WeMos ESP32 Pinout

This module is packaged as WeMos compatible board. I’ve used the Wemos ESP8266 modules previously and they provide a neat stackable package with a few pre-built modules for SD card readers, OLED displays, etc.

Plugging the module in and viewing the serial data on boot at 115200 baud shows that ‘Happy Buddha Trading’ appear to install some test software on the device. It doesn’t seem to create a Wifi hotspot, but it does activate the Bluetooth module, which I can view from a phone but not pair to.

ets Jun 8 2016 00:22:57

rst:0x1 (POWERON_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
ets Jun 8 2016 00:22:57

rst:0x10 (RTCWDT_RTC_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0x00
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0008,len:8
load:0x3fff0010,len:160
load:0x40078000,len:10632
load:0x40080000,len:252
entry 0x40080034
BTDM CONTROLLER VERSION: 010101
btip start
copy .data from 4000d890 to 3ffae6e0, len 00001830
set .bss 0x0 from 3ffb8000 to 3ffbff70, len 00007f70
BTDM ROM VERSION 0101
BD_ADDR: 24:0A:C4:01:61:0E
NVDS MAGIC FAILED
RF Init OK with coex
Enable Classic BT
Enable Low Energy

Tested by Happy Buddha Trading

ESP32 Chip ID = 0C6101C40A24
ESP32 SDK: v2.0-rc1-803-g1e0710f1
Bluetooth LE Device 'ESP32_SimpleBLE started

Starting Wifi scan
Scan complete
2 networks found
1: TV License Surveillance (-69)
2: TALKTALKC4B0EE (-77)

ESP8266 Arduino `.text’ will not fit in region `iram1_0_seg’ Error

I’ve been writing some software for a Wifi based CAN data logger for the ESP8266 in the Arduino platform, and have been getting a bit of a strange error. It appeared to be related to using the std::string functions in my code – and although I have used this in other sketches without issue, I suddenly received the following error as soon as I simply declared a std::string variable:

c:/users/scott/appdata/local/arduino15/packages/esp8266/tools/xtensa-lx106-elf-gcc/1.20.0-26-gb404fb9-2/bin/../lib/gcc/xtensa-lx106-elf/4.8.2/../../../../xtensa-lx106-elf/bin/ld.exe: C:\Users\Scott\AppData\Local\Temp\build525647f6f8500d071cfab5cccf314276.tmp/ESPCANLogger.ino.elf section `.text' will not fit in region `iram1_0_seg'

collect2.exe: error: ld returned 1 exit status

A bit of googling appears to show that this is something to do with where those std libraries are stored in the code memory of the ESP8266 (I don’t fully understand the details of the chip). The issue is described in this issue in the Arduino ESP8266 github issues log:

https://github.com/esp8266/Arduino/issues/2794

There is a fix shown in this pull request

https://github.com/esp8266/Arduino/pull/2804/files

I had a bit of trouble locating the file referred to, because the Arduino boards manager doesn’t appear to store the added boards in the Program Files location anymore, but these are now located in the AppData folder in your user profile (on Windows 8)

C:\Users\USERNAME\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266\2.3.0\tools\sdk\ld\eagle.app.v6.common.ld

The line which appears to fix it all should be added around line 163:

*libstdc++.a:(.literal .text .literal.* .text.*)

So my file then looked like this:

*libsmartconfig.a:(.literal .text .literal.* .text.*)
*libstdc++.a:(.literal .text .literal.* .text.*)
*(.irom0.literal .irom.literal .irom.text.literal .irom0.text .irom.text .irom.text.*)

There is some more detailed explanation about memory inside the ESP8266 here: https://tech.scargill.net/esp8266-ram/

ILI9341 and XPT2046 TFT display on ESP8266

For my own future reference more than anything else, to get the ILI9341 (either Adafruit or otherwise) working on the ESP8266 using the Arduino development environment isn’t completely straightforward. I knew I had this working previously, but couldn’t find the info again, so am copying it here.

It would appear that the ILI9341 library currently available through the Arduino Sketch -> Include Library -> Manage Libraries is not currently compatible with the ESP8266. Thus you have to download the working library directly from the Adafruit Github repository. However, I also had issues with this version. Finally I used the examples on http://nailbuster.com/?page_id=341 to get it working.

Additionally, the XPT2046 library available in the Arduino manage libraries feature does not support Hardware SPI, however there is an alternative developed by [spapadim] on Github. I took the following steps to compile some example code.

  1. Wire up ESP and Touch screen according to http://nailbuster.com/?page_id=341
  2. Download the zip file from the end of the page on http://nailbuster.com/?page_id=341 this includes some working examples
  3. Download XPT2046 library from Github https://github.com/spapadim/XPT2046
  4. Go to Arduino IDE -> Sketch -> Include Library -> Manage Libraries -> Search GFX and install the “Adadfruit GFX Library”
  5. Open the example sketch from Nailbuster and compile and upload

I have a feeling these libraries may be a little out of date now so I’ll have a look at whether they can be updated to use the latest versions available from Adafruit.

Thoughts on Graphical/Visual Programming Languages

​I dont see a lot of information on personal blogs/diy projects regarding the use of Visual Programming Languages, but this is what I use in my current role as a Control System Engineer developing engine control and test systems. I actually call them graphical programming languages, so if I use the terms interchangably here then I’m actually talking about the same thing. We use visual programming languages for engine ECU control code and Test Cell control code (Simulink + Stateflow and Labview respectively). I believe graphical programming languages are pretty widely used in the automotive industry, and appear to have massive buy in from plenty of other industries too. I think its easy to see why.

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ESP8266 Successor – ESP32 released with CAN bus support 

So, the interesting little ESP8266 WiFi SoC finally has a younger brother which appears to be even more capable. Among other expansive updates, the 32 bit Dual Core microcontroller still supports WiFi, but also Bluetooth Low Energy, a DAC, many more ADCs, GPIO pins, etc. etc. Lots of good details here: http://esp32.net/ 

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ESP8266 CAN Bus with MCP2515

I have just bought another ESP8266/NodeMCU development board cheapy from eBay (this one) with an ESP-12E chip on board. I’ve also bought an SPI-CAN bus interface with the common Microchip MCP2515 CAN controller to try and create a CAN-Wifi gateway.

The pinout for the ESP-12E NodeMCU board is apparently as below:
ESP-12E NodeMCU Pinout

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ESP8266 Development/SDK Board

Warning: do not connect the DHT11 temperature sensor as indicated in the eBay pictures, it is the wrong way around and will fry your board!

Update: Board has arrived, more details and pinout here

It would seem that the ESP8266 is quickly becoming a pretty well supported WiFI microcontroller within the DIY/hacker community, and certainly presents itself as a pretty good alternative to an Arduino for projects requiring simple IO and WiFi. There’s even a project looking at using compiling the Arduino IDE and compatible code for the ESP8266!

Chinese ESP8266 Breakout board

Chinese ESP8266 Breakout board

I have one of the original versions of these units, but ave struggled to get anything sensible out of it, and so was looking on Ebay for some more items and came across this breakout/development board. For £9.99 I thought I’d give it a go, and ordered it a couple of weeks ago. Will give more details when it arrives. More details and pics after the break

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Arduino ECU By Brenamanf

I was sent a link to this website by the author, who appears to have created an Arduino ECU for spark control. Although the details are a little sparse, It appears that he has developed a lot of the required hardware himself. It looks like the main controller is an Arduino Nano and utilises Manifold Absolute Pressure (MAP) and a knock sensor to determine the ignition timing on a Peugeot 205 Tu9 45Ch. It would appear that the ECU has been developed over a number of revisions and has been in operation for over a year.

http://brenamanf.wordpress.com/page/2/