Friday, January 22, 2016

Fab Academy16  "This paper presents the composition and the rationale behind the creation of a network of fabrication laboratories, FAB LABs, whose mission is to provide concrete examples that would lay the foundation for a new framework for this reconceptualization. "

weekly builds and guides at

Saturday, January 2, 2016

Sous Vide sur Internet: Node-RED, MQTT, ESP8266

Sous Vide sur Internet: Node-RED, MQTT, ESP8266

Cooking over the Internet has always been my pet peeve. That is when I could marry two of my best loves, maybe into a product that pays. Sous Vide sur Internet, is in French, loosely translated to sous vide over the Internet. well, it doesn't takes much of my agar-logic to get the translation.

Just a little bit of trivia:
Back in 2010, 2 of my padawans are working on a Final Year Project making a web2.0 smart fridge that tracks item in the fridge by QR code follow by suggesting a youtube cooking video based on the items in the smart fridge. When DIY Sous Vide is all the rage on the Internet, I have my own fair share of experiments with sous vide with a myriad of implementations. Back in 2012, one of my padawans took it up the challenge to build a sous vide shield for arduino

Fast forward to 2016, The notion of Internet Enabling dumb devices aka household appliances is all in the rage. The release of ESP8266, a very cheap (USD4 at Dec2014) WiFi enabled microcontroller has kick start a whole plethora of IoT devices fuelling the development of devices once seem dumb. The Maker's IoT Kit and the detail step by step guide on how to use ESP8266, maker IoT Kit break out board with arduino IDE located here is one such enabler to make dumb terminals smart by connecting to the Internet.

Having the ESP8266, the Maker's IoT Kit for ESP8266 is only one third of the whole picture of the end to end IoT solution.

The complete end to end IoT solution will have 3 parts,
1. the Internet Enabled device with sensors
2. the computing and data aggregation platform aka cloud computing
3. the visualization over the Internet

Earlier, the Internet Enabled sensor was addressed in this post in detail The visualization of data was addressed in an earlier post too, via thingspeak.

The computing and data aggregation platform is the gist of this guide. In the earlier post, the protocol of chose to stream data is via HTTP. There are pros & cons associated with this protocol in the implementation of IoT end to end solution, this post is not going to delve deep into the discussion of it. Assuming there are 1000000 IoT devices, quite chatty (in terms of data transmission) talking to a data aggregation server (assume to have 1 server in this discussion) concurrently via HTTP. The server might run into a resource squeeze after N-th connection. Hence MQTT comes to the rescue. MQTT is an "archaic" protocol (invented in 1999 by scientist working for IBM), partially revived by engineers working in Facebook for the real-time messaging function .  MQTT follows a PubSub model, where sensors subscribed to a "topic" to listen to control command or publish to a "topic" to stream data to the data aggregation server.

In this guide, several software components are needed, on top of the hardware component Maker's IoT Kit for ESP8266.

Software needed
1. Ubuntu Server 14.04 on a physical computer or virtual machine on the cloud
2. MQTT protocol, the broker used here is mosquito MQTT
3. Node-RED as the data aggregation platform

The instructions to install the software on ubuntu is at the footer of this guide.

In the diagram above, the putty window on the right is the MQTT client, publishing data "data2" to the MQTT broker which is the putty window on the left. Node-RED is in the background, capturing the data transmission from MQTT client and MQTT broker, and it gives a visual on the "wiring" of the end to end IoT solution,

The Diagram follows the same arrangement as the previous, but with the addition of an ESP8266 enabled with temperature sensor to stream temperature data to thingspeak via HTTP, and to Node-RED via MQTT. We now have an end to end IoT Solution. but wait, it is unidirectional. the data only travels from the IoT sensor to the data aggregation server, but not the other way round. control needs to be issued from a server, just to complete the bidirectional communication possibly for an IoT solution.
Setting up the corresponding MQTT broker on Node-RED is very easy. simply drag the MQTT icon from the left hand side, and place it in the "canvas". edit the MQTT broker parameters accordingly.

Node-RED provides a visualization of IoT device, data aggregation, and it's connection, MQTT would function too. The above diagram describes the MQTT broker and the MQTT client in action.
The diagram above describes the Node-Red in operation, and the step by step guide to install additional "nodes" aka functionality to Node-Red
The diagram above describes the successful addition of a PID controller for Node-RED.
Are you thinking of what i am thinking? YES, cooking sous vide over Internet!! IoT sensor send the temperature of the cooking to Node-Red via MQTT. The computation of the PID based on the receive temperature data and the set point is offloaded from the ESP8266 to the Node-RED that is hosted on a virtual machine with much more muscle power as compared relatively. The delta, i.e turning on the heating element is the command to be sent from the computing platform to the ESP8266 IoT sensor that controls the relay. 

The source code for the ESP8266 temperature control and relay control is available at the footer. The above diagram describes the detail of the upload.

The above diagram describes the wiring of the Maker's IoT kit for ESP8266 to a multiplug modified with a solid state relay. The step by step guide of making the SSR plug is here or here

The following diagrams describe the testing of the Sous Vide over Internet setup with Maker's IoT Kit for ESP8266, MQTT, and Node-RED 
data aggregation and computation on Node-RED, data visualization on thingspeak
testing of the set point at 30degC

tuning parameters for PID
comparing the data output on serial from ESP8266, and Node-RED

ESP8266 MQTT and ThingSpeak code here:

Node-RED setup here: 

Thursday, December 24, 2015

Beginner's ESP32 guide to getting started

Beginner's ESP32 guide to getting started

Yours truly is one of the lucky 200 to receive an ESP32 for beta testing. The neat little package came few days before Christmas. indeed, Christmas came early! It is a tough call, wrestling with the decision to roast the bird for Christmas eve dinner or to explore the ESP32. The latter won! we shall have chinese takeaways for dinner later.

A little bit of trivia. Back in June15 at MakerFaire Shenzhen, yours truly was sitting in the same row with the real mccoy whom created the ESP8266, listening to the real arduino giving a keynote on the yet to be released Genuino, and not forgetting yours truly getting his paws on the newly released nodeMCU v1.0 (black) from "zhao zhong 赵总" at a very competitive price.

ESP32 was featured on MAKE, Hackaday, and Adafruit. Do check the reference section for the details. Conventional wisdom assumes ESP32 is going to supersede the hugely successful ESP8266 for IoT application. But yours truly begs to differ. ESP8266 is targeted at the "everything" market, where gazilllions of IoT enabled sensors aka "throwies" are deployed to form an ubiquitous computing framework to collect data on just about anything! A plethora of boards manufacturer have utilized the ESP8266 in their respective iteration of IoT with cloud offerings. Hence the "everything". The ESP32 sports much bigger processing power, more RAM, and most importantly encryption at hardware level. Perfect timing to address the insecurities in the IoT devices sending data in clear text over the network via http or mqtt. ESP8266 is going for USD4 (got it for SGD9 at 2014). Unfortunately, the users (yours truly included) do not have the slightest hint on the price for the ESP32.

Below is a quick summary of the ESP32

Faster WiFi: Wifi has been upgraded to support HT40 speed (150 Mbps)
Bluetooth Low Energy (BLE) and Classic Bluetooth
Dual processor: 2x Tensilica L108 processors clocked at up to 160 MHz
Low Power Mode: deep sleep, etc.....
IO: Capacitive touch, ADCs, DACs, I2C. UART, SPI, SDIO, I2S, RMII, PMW
RAM: 400 KB on-chip RAM
Security for IoT: Hardware accelerated AES and SSL, etc

If you could recall about a year or so when ESP8266 was first released, the lack of proper, consistent, and precise documentation in the English Language has led to many frustrations among the early adopters. Great progress we have witnessed in 2015 for the developments of the ESP83266 by the members of this community. Makers alike, yours truly paid his due diligence in sharing a how-to guide on instructables to address the inconsistency. This time round with ESP32, the documentations are much better!! Sorry, could not share the documentations now due to confidentiality. Let's wait for the full release straight from the horse's mouth. IMHO the documentations can still be a steep learning curve for the beginner. Furthermore, the QFN -ish packaged ESP32 chip that is fully assembled on a breakout board sports a 1.27mm (50mils) spacing between the pins (pitch) on the supposedly breakout board. It is very intimidating to solder onto the other provided breakout board to make it breadboard friendly. A beta tester has reported on an unfortunate event of damaged ESP32 Another beta tester have used the solder paste + heat gun method

This i'ble is an ongoing process aims at addressing the following

0. prep the ESP32 breakout board for prototyping on a breadboard

1. initial powering up and observations

2. setting up of programming environment + hello world

3. references

Soldering the ESP32 breakout board

parts needed
1. a 200 DegC temperature regulated, very fine tip solder iron, and 0.4mm solder.

2. heat gun. optional. useful if need to remove solder for SMD re-soldering work

3. soldering wick

4. solder flux and applicator

5. PCB vice of some sort

check out the annotations in the picture for a visualization on items needed


1. Practice some surface mount soldering before committing. yours truly only have 1 eval unit and can't afford to screw it up. If you have soldered ESP-12 and it's breakout board, it is definitely good experience. HIghly recommended to do SMD soldering in a well lit work area.

2. The ESP32 break out board moves around easily on the breakout board for breadboard. A tape of some sort is used to secure it in place. Make sure the pins are aligned properly on the 3 sides. Perhaps some heatsink compound can be applied on the small square on the breakout board for breadboard, and then the ESP32 board aligned on it. The tackiness of the heatsink compound will help to make the ESP32 stay in place.

3. Always ensure the pins are perfectly aligned on the ESP32 board to the breakout board for breadboard that is secured with a PCB vice. Apply solder flux on the soldering surface. If you are right hander, positions the pins to be soldered to be on your right hand side, such that your soldering movement is moving towards the right, bring the melted 0.4mm solder perpendicularly away from the neighbouring pins. 1.27mm spacing can be quite nerve wrecking to solder, and the random thoughts of screwing up is so strong! stay focus!

4. start soldering from the ground pins. Refer to the pin out diagram, there are 3 of them, one on each side of the ESP32 breakout board, and located at a convenient corner. Speaking from yours truly own experience in soldering the ESP32, if one of these is screw up, still have 2 more to go :) Once the 3 ground pins are soldered, the ESP32 should be perfectly aligned and sits securely on the breakout board for breadboard.

5. repeat step3 until all pins are soldered

Examine the solder work

Examine the SMD soldering under a magnifying glass for dry joints. Excess solder is fine as long as it doesn't overflow to neighbouring pins. A smartphone camera with it's magnifying function works well too.

It is recommended to fix the dry joints with another round of soldering.

If there are excess solder onto the neighbouring joints, use the soldering wick and heat it up with the solder iron or hot air gun to remove the excess.

once satisfied with the SMD soldering work, continue to solder the PTH male header pins.

check out the pictures for details

Powering up the ESP32 with CP2102 for the first time

Parts needed

1. CP2102 or any USB to TTL device

2. jumper wires


1. connect 3V3 and GND from CP2102 to ESP32.

2. connect TX of CP2102 to RX of ESP32, and RX of CP2102 to TX of ESP32

3. EN pin on ESP32 left floating ---> update: check out the next step for wiring a reset button

4. plug in CP2102 to USB port of computer


At first light, only the CP2102 lights up. yours truly thought he is going to have a piece of bricked ESP32 for Christmas, the thought of it is already depressing. As compared to the ESP8266 that sports a blue and a red LED, The ESP32 does not have any lights to indicate activity??? Upon further probing, under the wireless network of his win8.1, the ESP32 network shows up. what a relief :)

Putty with the setting of 115200 8 N 1 no flowcontrol is used to monitor the serial output of the ESP32 via CP2102. The screenshot here is so much different from Martin's. Not sure why is this so at the moment of writing -> update: check out the next step for wiring a reset button.

Powering up the second time with a reset switch

continuing from the previous step, some modifications to it.

the EN pin on ESP32 is pull high with a 10K resistor, and then grounded via push button switch to reset the ESP32 if asserted. Using putty with the setting of 115200 8 N 1 and no flow control, the same output is acquire as per martin's blog, just by resetting the ESP32 using the newly added push button. refer to picture for the details.

Setting up minicom

yours truly decide to setup minicom on ubuntu14.10 hosted in a virtual machine. Perhaps there is some command can be issued to the ESP32 to give the same output as martin's.

check out the screenshots for the commands and observations.

Still not a single clue of the debug message on the serial comm. Time to RTFM in detail.

Setting up the software enviroment & hello world

place holder for future updates

quick update1: the installation of the cross tool keeps breaking on a u14.04 Server 64bit hosted in a VM on w8.1. still probing around the error messages displayed

quick update2: after fixing some broken dependencies, finally the *.bin are compiled successfully. check out the screenshots. Next, need to figure out what's the functionality of the *.bin compiled from the provided "project_template". Then decides whether to upload to the ESP32 or otherwise. Still finding a way to "backup" the out of the box *.bin in the ESP32. just as an insurance to recover from mistakes.




Martin's :

also on Instructables

Thank you

thank you for coming thus far.

special thanks to

espressif CEO & reps for the ESP32

Mr.Dorville for the loan of SMD rework soldering station.

Merry Christmas 201

Friday, December 18, 2015

Lightsaber ala over-easy

running short of time to make a lightsaber to bring along to the cinema to watch the latest installation of starwars? fret not. you will make your own lightsaber in about 30 minutes or so and still able to make it in time to rescue princess leia. 
many years back, yours truly have made a DIY lightsaber with a differnt methodology, URL here
In this guide, we will be making a lightsaber ala over-easy; we shall address the electromechanics needed to build a lightsaber with surpluses from previous project. The design of the lightsaber holder deserves an i'ble by itself.
lightsaber over-easy is de-constructed as per the following parts needed
1. a diffuser. In this i'ble i have used 5mm OD side glow fiber optics inserted into a 10mm OD acrylic tube.
2. a light source. There are 2 flavours here. one with a 3W blue LED, and the other with a lightsaber holder look-alike torchlight.
3. power supply. 5V from a mobile power bank made with 18650 cells or coin cells.
4. 3D printed holder of some sort to bind the diffuser, the light source, and the power supply.

a 5V USB power bank is used as the power source to turn on a blue 3W LED mounted on a heat sink.
Assuming the forward bias voltage is 3.3v, and ideal current of 350mA, i would need a 4ohm 2W resistor. I only have a 10ohm 2W resistor handy.
to construct the light source, these are the items used
1. small veroboard
2. 1x USB male connector
3. 1x 3W LED (BLUE) mounted on the heatsink, collimator (focus beamacr) is optional
4. 1x 2W 4ohm resistor
5. 1x usb mobile power bank made with 18650 cells
*note: the 3W LED and resistor get hot after several minutes of play.
The force must have led me to discover this lightsaber holder look-alike torch light that was well hidden deep inside the goods cabinet in the local hardware shop.
The acrylic tube inserted with the sideglow fiber optics is connected to the lightsaber holder look-alike torch light with a 3D printed adapter.
Link to the 3D model of the lightsaber adapter here
check out the pictures for a detail description on the assembly

Do or do not, there is no try.

Sunday, November 1, 2015

Maker's IoT Kit for ESP8266 (ESP-01)

Maker's IoT Kit for ESP8266 (ESP-01)

the real McCoy PCB milled on LPKF103

Ah, the beloved ESP8266, so many variants, so many choices, so many different pricing points, the one true chip (read: cheap) that offers internet connectivity to the unplugged. but which one is suitable for me? Since ESP8266's inception, with the debut of the ESP-01, a myriad of ESP8266s'have been released. Starting form ESP-01 to the latest addition that sports ESP12E , and finally the WROOM. The debut started with ESP-01 URL, an U$4 (yours truly got it for S$9 from a local vendor back in 2014) full featured ESP8266 but only 2 I/O the GPIO0 and GPIO2 are break out in the form of the DIP pin package. Along the way, ESP7, ESP12, ESP12E, came by. These ESPes' lack of one thing in common to facilitate a maker to rapid prototype an IoT idea: a daughter board that breaks out the I/O (breadboard friendly or otherwise) to control stuff over the internet URL , and at the minimum comes with a 3V3 voltage regulator. Finally the holy grail of all ESP, the NodeMCU URL, a full featured ESP8266 ESP12E with 10 I/Os break out conveniently and just need to be plugged on a breakboard to be usable. A standalone NodeMCU is easily USD9 per pop. One might argue the entry pricing point is cheap, but one has to remember the price excludes the accessories. The "shield" for nodeMCU can be as costly as the nodeMCU itself.

For a maker that wants to bring the prototype built with ESP8266 out of the breadboard environment, into a deployment environment, the said prototype has to be fully robust, and survive a few hard knocks in the "real world". An ESP8266 planted on a breadboard with loads of interconnected wire as if it is a prop straight out of a Hollywood sci-fi bomb is not going to cut it. A (poor) maker is left with not much of a choice but have to solder it on a stripboard, and hopefully the VC will fancy it. IoT enabled devices are on the rage when this come to the economies of scale; A prototype demo during an elevator pitch with a gazillion IoT devices definitely going to pack a heavy punch as compared to a demo with a lone IoT device. oh wait, solder a gazillion prototypes to test out the economics of scale for IoT?!

The Maker's IoT Kit for ESP8266 (ESP-01) has a unique standpoint point in the landscape of ESP8266 enabled IoT devices. It has a very low entry barrier on the technical department. It addresses the total cost of ownership pricing issue with the choice of ESP8266 ESP-01, and the need for a minimum of 1 input and 1 output to be interfaced with sensor & actuator, just to be useful enough to control things over the Internet. Essentially, Maker's IoT Kit is a break out board (BoB) for ESP8266 ESP-01 that fully embrace the design "philosophy" behind ESP-01: Low cost, testing of IoT ideas by rapid prototyping with ESP-01, and deployable en masse. The beauty of Maker's IoT Kit: it address the choice to remain free from obligations & restrictions; there is no tie in to a specific set of I/O board manufacturers. Approx U$2 for ESP-01, U$0.5 for The Maker's IoT Kit, total cost of an IoT device that supports 1 input and 1 output can be as low as U$2.5. Surely any research grant handed to yours truly will enable many many IoT devices to be deployed.

Prior to the release of ArduinoIDE-for-ESP8266, an Arduino Uno or Arduino Mega is needed to piggy back the ESP8266. To the layman, an Arduino IDE is definitely much "friendlier" compared to Writing a custom firmware using espresif SDK on Eclipse. The technical barrier to get started with the SDK is somewhat complex to the naked untrained eye. Ah, and not forgetting the constant swapping the ESP-01 boards between programming mode and prototype testing mode; compiling, and downloading the compiled code to ESP8266 with CP2102, and then transplant IO board to interface with the sensors. In hindsight, the Maker's IoT Kit for ESP8266 (ESP-01) was born out of regenerative iterating prototypes to quickly test out IoT ideas.

The design principles of The Maker's IoT Kit for ESP8266 (ESP-01) are listed in the following.

The Maker's IoT Kit is both a programmer board with the use of CP2102 as the USB serial, and also a prototyping board. To change between the programming mode and the prototyping mode is done With the help of a jumper. The PCB is designed as a single layer PCB on purpose, lowering the entry barrier for it to be easily reproduced by any PCB milling machine available in workshops, FabLabs or maker spaces. It coveniently breaks out GPIO0 and GPIO2 for the ESP8266 ESP-01. GPIO2 is used for 3V3 input device, and GPIO0 is used for 3v3 output device. By design, a 5V output is available on GPIO0, and this is done with additional NPN transistor.  Assuming the prototype and source code behaves according to specifications, then the ESP8266 ESP-01 can be left as it is on the Maker's IoT Kit to be deployed in the field and to collect data of interest. Power supply to the prototypes built with ESP8266 has been a constant headache, especially deployed outdoors. This Maker's IoT Kit sports 3 possible inputs for power supply. first the 5V from the CP2102. this mode is only recommended for programming the ESP8266, but not for deployment due to the current required by ESP8266. Next, a 2pin molex pin for power supply from DC adapter. The voltage from DC adapter varies from 5v to 12v, as long as it is within the specs of the LM317 voltage regulator. Lastly, power supply via USB B port, this opens a much wider selection ranging from power banks to mobile phone charger. A diode is added to the USB B port, due to an experience of magic smoke stemming from a bad USB cables powering my precious. no brownie points for guessing where the cables orginated from.

Learning from collective wisdom of ESP8266 enthusiasts, the peculiarity of ESP8266 GPIO0 turning high during bootup is addressed by the NPN transistor.

first iteration

fifth iteration

powered via laptop USB port to CP2102 to down load the program into ESP-01

powered via USB B port connected to powerbank

powered by 4x AA battery connected to 2pin molex pin

use this URL to download the gerber file

First, download the gerber and mill the Maker's IoT Kit for ESP8266 (ESP-01). Solder the necessary electronic components on the milled PCB w.r.t the schematic posted here. plug in a CP2102, and the ESP-01 on the daughter board, take special precautions on the polarity and orientation of the pin out. Set the jumper "p-mode" to programming mode (short the left and middle pin). Plug the CP2102 end to a computer equipped with Arduino-ESP8266. The steps are quite similar to this guide, just take note in the board to be selected is "ESP8266 Generic". compile and download source code to ESP-01.
Once download is completed, unplug from computer; then unplug CP2102 from daughter board. Set the jumper "p-mode" to operation mode (short the right and middle pin), plug in a power supply of choice, and you are good to IoT your way to the cloud.

So, what to make with it?

for starters yours truly have tested the The Maker's IoT Kit with ESP8266 (ESP-01) with a DS18B20 temperature probe as input, LED as output. The temperature data is sent wirelessly to thingspeak, and the LED simulates the turning on/off of a load in-place of a Solid State Relay (SSR). Yes, as of what you have guessed, yours truly is going to up the ante to build a sous vide that is controllable over the internet via wireless network. In short, the cooking temperature can be changed, monitored and recorded over the Internet during sousvide cooking. Think along the line of you browsing popular sous vide cooking website, and there is a "cook" button next to your favourite dish. Magically, your sous vide meal will be prepared when you are back from work. of course, some devine intervention of acquiring the edibles, packing it into a vacuum bag, and lowering it into a sous vide water bath equipped with ESP01 is required.  An earlier iteration URL 

in this post, we only address the hardware part of a ESP8266 enabled IoT devices, and this is hardly half of the entire story told. The parts missing are communication stacks with MQTT, a cloud computing solution to act as the collector and aggregator of data, and of course, the holy grail of all this IoT craze: Predictive analytics from the data collected. An earlier iteration with thingspeak

nodered on Ubuntu to be used with ESP8266 

code here:

special thanks to my padawans jia yi, william tan, bryan, and etc for strip board, manning the PCB milling machine, sourcing for milling bits and cheap copper boards, and testing.