Wheel encoder

Cables and connectors

• Socket: SM03B-SRSS-TB
  
  

  Open

  

• Housing: SHR-03V-S-B
  
  

  Open

  

• Terminator: SSH-003T-P0.2-H
  
  

Hall sensor

TBD: test the TMAG5123D version on a rectangular magnet

https://www.ti.com/product/TMAG5123#design-tools-simulation

Back wheels: https://www.supermagnete.ch/eng/block-magnets-neodymium/block-magnet-5mm-2.5mm-1.5mm_Q-05-2.5-1.5-HN

Front wheels: https://www.supermagnete.ch/eng/disc-magnets-neodymium/disc-magnet-2.5mm-1mm_S-2.5-01-N52N

Tests

“New“ Buggy

this is the buggy which has a new drive motor gear ration 6:35 instead of 11:35

At 5V motor input we get:

229/8=28.6 Hz or 1717 RPM

0.425 ms is our delta with a “fixed“ speed on the motors

2.715 + 0.425/2 = 2.9275 ms would be the “true“ speed then we have a +- of 0.2125ms or +-7.25%

the delta looks to be similar when applying 4V and 3V respectively.

Note that this measurement is using an envelope function on the scope so 7.25% would be between two magnets on the wheel, the actual delta between adjacent magnets can still be better.

Bench test 100% speed

The rc car was placed on the bench an a cylindrical magnet was attached on the wheel and the sensor mounted just next too it. The motors was supplied with a constant 5.5V and left for ~5sec until the rpm settled.

we can see a frequency of ~46Hz and a delta on the low pulse of +-0.129ms.