ESP32 E‑Paper Status Display

ESP32 E‑Paper Status Display

Using an ESP-32 board with an embed­ded E‑Paper dis­play, I cre­at­ed a gad­get that shows sta­tus infor­ma­tion from my web server.

E‑Paper, also known as E‑Ink, only needs pow­er when being updat­ed, and uses no pow­er between updates. This means that the gad­get can be pow­ered for weeks from a recharge­able battery.

The pur­pose of this gad­get is to put on my wall or desk, and show reg­u­lar­ly updat­ed impor­tant infor­ma­tion on my web serv­er, to keep informed of web site prob­lems and sta­tis­tics. The infor­ma­tion dis­played can be eas­i­ly changed, for exam­ple to the lat­est weath­er, news, cur­ren­cy prices or any­thing that can be accessed via the inter­net. E‑Paper means it uses a very small amount of pow­er and heat, com­pared to a com­put­er dis­play or television.

You can view my code on GitHub if you are inter­est­ed in mak­ing your own.

ESP32 E-Paper Display
ESP32 E-Paper Display
ESP32 E-Paper Display
Anonymous Traffic Survey Cameras

Anonymous Traffic Survey Cameras

Manual Traffic Surveys

Many peo­ple in the UK may be famil­iar with see­ing groups of peo­ple, or some­times a parked vechi­cle, clear­ly dis­play­ing a sign say­ing ‘Traf­fic Sur­vey.’ These peo­ple are employed to keep a tal­ly of the num­ber of vehi­cles using a road, and the types of vehi­cles. This infor­ma­tion is impor­tant for plan­ning infra­struc­ture, help­ing more effi­cient pro­vi­sion of trans­port capac­i­ty for cars, trucks/lorries and buses.

Pressure Sensors

Pressure-sensitive Traffic Data Collection System (from
Pres­sure-sen­si­tive Traf­fic Data Col­lec­tion Sys­tem (from

Many will also have seen tem­po­rary pres­sure sen­sors across roads, linked to a data col­lec­tion box attached to a street lamp. This sys­tem also pro­vides use­ful data on the num­ber of vehi­cles using a road.

By using two pres­sure sen­sors, its pos­si­ble to fair­ly accu­rate­ly record the num­bers of vehi­cles pass­ing in two direc­tions. How­ev­er, there may be some inac­cu­ra­cies when vehi­cles pass simul­ta­ne­ous­ly or almost simul­ta­ne­ous­ly. A 15-minute time peri­od may have an inac­cu­ra­cy of 10% ( For roads with more than two lanes, accu­ra­cy would be even less and the sys­tem prob­a­bly would­n’t be feasible.

Electronic Sensors

Piezoelectric Sensor Dug into Road
Piezo­elec­tric Sen­sor Dug into Road

There are also elec­tron­ic solu­tions dug into roads, which I’ve noticed on approach­es to traf­fic lights. These may be used to alter tim­ings of traf­fic lights depend­ing on traf­fic, and it seems they could also be used for traf­fic sur­vey data col­lec­tion. You may have noticed traf­fic lights chang­ing as you approach them, and a sys­tem like this may be detect­ing the mechan­i­cal ener­gy of your vehi­cle pass­ing over sen­sors. I expect there are also mag­net­ic ver­sions of these sen­sors, that sense the metal­lic body of a vehi­cle. Some­times motor­cy­cles in the US do not trig­ger these sys­tems at auto­mat­ed inter­sec­tions, caus­ing prob­lems, and some state laws allow­ing vehi­cles to pass if a sen­sor fails to detect a vehi­cle’s presence.

Video Surveys

Scout Pole­mount Traf­fic Sur­vey Camera

I’ve noticed what seems like a new tech­nol­o­gy recent­ly, with a video cam­era mount­ed on a street light, and a data col­lec­tion box attached to it. After research­ing it, these are video cam­eras that record con­ven­tion­al HD video for a peri­od of 3 to 7 days. The mod­el I saw in use also has advanced fea­tures like remote man­age­ment and event alerts sent via mobile cel­lu­lar net­works (LTE), allow­ing set­tings to be changed and noti­fi­ca­tions of prob­lems with­out hav­ing to trav­el back to where the unit is deployed.

Computer Vision (CV)

I expect com­put­er vision tech­niques (e.g. OpenCV) are lat­er used to analyse the num­bers and types of vehi­cles passing:

Anonymity and Privacy

I expect there are strict rules in place to pre­vent ANPR (Auto­mat­ic Num­ber Plate Recog­ni­tion) being used, as this may vio­late the pri­va­cy of dri­vers. How­ev­er, if there are not, I expect trav­el time sur­veys could be made by cal­cu­lat­ing how long a com­mute takes for indi­vid­ual dri­vers, and how they change over time. Per­haps if this was cal­cu­lat­ed anony­mous­ly, it would be a usable technique.

While there have been com­pa­nies that have mon­i­tored cell­phones with Blue­tooth and Wi-Fi ser­i­al num­bers, often the gen­er­al pub­lic have expressed con­cerns over pri­va­cy. An exam­ple hard­ware provider for this is

In con­clu­sion, I found it inter­est­ing to research what these cam­eras and oth­er equip­ment I see are used for, and expect it is an inter­est­ing field analysing queues of videos for traf­fic data.

Sony Noise Cancelling Headphones as Binaural Microphones

Sony Noise Cancelling Headphones as Binaural Microphones

My Sony smart­phone has an unusu­al TRRRS (Tip-Ring-Ring-Ring-Seal) con­nec­tor, allow­ing it to use very rea­son­ably priced noise can­celling head­phones (Sony MDR-NC31EM) that have an extra micro­phone in each earphone.

I found that the Sony app Sound Recorder allows select­ing record­ing direct­ly from these two micro­phones, and are great for bin­au­r­al record­ing, and I gave it a go walk­ing along a few busy streets. You can lis­ten on YouTube and Soundcloud:

Open Bionics robotic hand for amputees

Open Bionics robotic hand for amputees

“A pro­to­type 3D-print­ed robot­ic hand that can be made faster and more cheap­ly than cur­rent alter­na­tives is this year’s UK win­ner of the James Dyson Award.” (BBC News link)

This is a fan­tas­tic idea, which has so much val­ue to peo­ple with­out limbs. Bion­ic pros­thet­ics can cost up to £100,000, and £30,000 for a sin­gle hand.

The 3D-print­ed robot­ic hand in the arti­cle costs £2,000, which is the same price as a pros­thet­ic hook, and offers sim­i­lar func­tion­al­i­ty to the top-of-the-range options.

The design­er gets to devel­op his inter­est in cre­at­ing a prod­uct, while help­ing the esti­mat­ed 11 mil­lion peo­ple who are hand amputees worldwide.

Open Bionics

Project Tango and Visual-Inertial Localization

Project Tango and Visual-Inertial Localization

This project enti­tled “Large-Scale, Real-Time, Visu­al-Iner­tial Local­iza­tion” is inter­est­ing, using Google’s exper­i­men­tal ‘Tan­go’ hard­ware to improve real-time track­ing of loca­tion and position.

The hard­ware is a tablet com­put­er with a motion track­ing cam­era, a 4 megapix­el 2µp pix­el cam­era, inte­grat­ed depth sens­ing and a high-per­for­mance proces­sor. This equip­ment aids in tasks like scan­ning rooms. A lim­it­ed num­ber of kits were pro­duced and giv­en or sold to pro­fes­sion­al devel­op­ers with the intent of mak­ing tech­no­log­i­cal developments.

One day we may see more accu­rate and inter­est­ing aug­ment­ed real­i­ty. I’ve often thought over­lay­ing infor­ma­tion onto our cur­rent real­i­ty would be inter­est­ing. Walk­ing down a street and see­ing for-sale signs could be inter­est­ing. It may just being over­loaded in adver­tis­ing, mak­ing a vir­tu­al eye­sore though.


Get Out of My Lab: Large-scale, Real-Time Visu­al-Iner­tial Localization
Simon Lynen, Torsten Sat­tler, Michael Bosse, Joel Hesch, Marc Polle­feys and Roland Siegwart.
Autonomous Sys­tems Lab, ETH Zurich
Com­put­er Vision and Geom­e­try Group, Depart­ment of Com­put­er Sci­ence, ETH Zurich