We previously tested a Hall effect sensor that, was working, but which gave us a voltage from which we could get the marble’s side. The issue with this is that in the final box, with all the marbles and the coils, we could have had strong pertubations that could alter the data. To avoid this issue we decided to use a sensor that would send the data through a communication protocol that could resist. We chose the TLE493DW2B6A0HTSA1 Infineon Technologies. This sensor sends its data through the I2C protocol so it should resist to our perturbations.
Let’s connect it !… Read more
Back to school after the holidays, we ran tests to validate our idea for detecting other Phyllos with IR radiations. Quick reminder, we had ordered two powerful IR transmitters (LTE-R38381S-ZF-U and SFH 4441) and several receivers, some in AGC2 (TSOP2256 and TSOP4856) and others in AGC4 (TSOP4456). Signal management is a little different depending on the type of gain control (AGC): some receivers are more suitable for noise reduction and other lower detection times.
We will briefly go through the IR detection protocol once again.
First of all, Phyllos give themselves a unique identifier by communicating via Wifi.… Read more
In the components familly, it was time for the Hall effect sensors to be tested.
We used the SS39ET from HonneyWell. This sensor has 3 pins. One is GND, one is Vcc and the last is the output. The output is a voltage proportional to the magnetic field. We choose for Vcc a value of 3.3V.
First tests, let’s use a voltmeter.
To do the first tests we measure the output voltage with a voltmeter. To power the device we used a DC power supply. We also added an ampermeter to measure the current going to the Hall effect sensor.… Read more
Yesterday we mostly worked out the detail of how we’ll be detecting neighbouring Phyllos.
Without further ado, here it is :
Step 1 : Discovery and identifier attribution
The first step for the Phyllos is to establish collectively which other Phyllos are present. Each Phyllo must therefore broadcast its presence and be given an identifier.
This step must be repeated regularly in case Phyllos are switched on/off.
As described in this post, we plan to base the protocol on wifi broadcast: a Phyllo regularly broadcasts its IP over wifi to signal that it is still on. The others register this IP address in a local running Phyllos table.… Read more
Last week, we thoroughly tested the MPU9250 that Alexis lent us. At first glance, it looked a lot more promising than the TLV493D-A1B6 MS2GO () we tried before : the range is way better ! Unfortunately, magnetic detection is more complicated than we first thought and it looks like it’s not going to cut it.
You can take a look at this post to remind you of the detection scheme we had in mind.
Essentially, the idea is to use electromagnet in every Phyllo that can be turned on and off, so as to detect the Phyllos one after another, and use Wifi or Bluetooth to coordinate.… Read more