Gareth's blog

My latest ESP32/Nextion touch screen Weather/bus/train times project required a realtime clock.... however it has taken me quite a few weeks to find a good solid solution.
Firstly :-
....if you want to stay sane then avoid epoch time (best thing that happened in 1970's was "punk Rock" not unix count my seconds since birth)....rant over.

Up till now I have been porting scans over the Serial wires and manually presenting the data.....

Now the Rig has its own Real-Time Debug TFT Display. (you might see it below the right wheel)

Above is just a 180° scan of this below :-

Wooden planks set at 90° and two DVD cases thrown in for measure.

I placed the Sensor rig into a cardboard box just to get a feeling for the data.

This is two passes of the probe, so you can see the slight variance in data.

Overlaying the raw data for 180°.... this was with GIMP so its just approximate

all looks kinda good except Hmmmm.... rounded corners cannot be explained...

another scan with DVD's :-

Its scanning, the stealthy Dual Time of Flight wiring was a soldering pig to execute (or should I say "Exterminate").

Data is flowing.... at momo a bit strange 200 Steps = 360° (until microstep instigated giving theoretical 1/16 steps ermm if my maths is correct 3200 Steps for 360° however at the price of speed)

Two is better than one...... (or 4 or 8 etcetcetc).

Following successful experiments with 1 single Time of Flight distance sensor mounted to Stepper, watching the scan process its seems to lend its self to setting the scan to just 180° and mount two sensors back to back to extract the whole 360°...... (or 90° scan with 4 sensors, hope you see where I am going with this :-)

Time of Flight meets BlueTooth.....

Extensive testing with WiFi mesh networks proved to be not the way to go for this project... timing issues killed the progress.

Exit Wifi Mesh network goblins...... YAY

Enter the BlueTeethed Elves ....... YAY

The ESP32 has up its sleeve BlueTooth capabilities, it was a simple job to reconvert the data packets.

Persistance pays off , ESP8266 Mesh network begins to work, this transmits sensor data from the Time of Flight Laser distancing module and the Compass module to the basestation rover.

The latest Plan (software Workio) :-

1.ProMini + TOF + Compass +ESP8266 sits on top of the 360° rotating Stepper motor (can be any speed literally (just limited up to the max that the TOF and compass can read data))

One step further in attempt to make a wireless system between the base rover station and the spinning Laser module.

In a Nutshell :-

Thought it may be of interest to document a rover platform using Stepper Motors as drive linked to an ESP32 sporting a Web gui to control movement and display Sensor data.

Here I present a "Touch Sensor" for InMoov's finger tip

Its uses a Full Bridge Strain Gauge circuit, this consists of 4 resistive strain elements and an instrumentation operational amplifier.

Basic Full Bridge :-

[1] Two active elements (one placed on top surface , other placed on bottom surface)