Donkey car odometer

thingiverse

[UPDATE 2019-10-09]: After multiple tests, disk with 3 holes is enough and best to have good velocity estimator with the recommended hall sensor from aliexpress (cf video description below: https://fr.aliexpress.com/item/32925980105.html?productId=32925980105). I didn't updated the photos above but I the final version is 3 holes and not 6 holes. This is an odomometer kit install for Donkeycar HSP-94186, one of the most popular donkeycar. https://www.robocarstore.com/products/hsp-94186-for-donkey-car This design has been inspired by Tawn Kramer Odomoter video title "Odometer Install on an Exceed Magnet Rc Car" https://www.youtube.com/watch?v=l0KUXxfalIQ I'm using hall sensor from Aliexpress referenced in comments section below video Magnet( 4*3) and hall board is referenced in Tawn Kramer video description. But why a kit install ? because the HSP-94186 doesn't have any hole in the main gear transmission ! Please take and look and contribute to donkeycar community ! :-) https://www.donkeycar.com Don't forget to add in manage.py the part below between brackets []: The configuration below has been successfully tested and is accurate on Jetson Nano !!!! >>> !!! VCC on PIN 2 (5V BUT with MANDATORY stepDown on 3.66V RMS !!! <<< PIN2 5V Jetson --> BEC set to 3.66V RMS --> VCC Hall sensor board pin 24 Jetson (physical pin == number printed on pcb) --> D0 Hall sensor board GND to GND This is the configuration listed on slack from @Doug and @Tawn (https://donkeycar.slack.com) -> Thanks to them ! It's the stepDown I use, setup on adjustable voltage. https://www.ebay.fr/itm/MINI-DCDC-UBEC-BEC-2-6s-DC-4-5-24V-Step-Down-Module-for-FPV-Multicopters/263066531711?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 Why not using 3.3V ??? because it's doesn't work at all at 3.3V: only one pulse with the Hall sensor recommend on youtube video from Tawn. It's why I use 5V down to 3.66V and in this case, works nicely.. cf JeanMarie thread on https://donkeycar.slack.com/archives/C487786DC/p1568841205039100 ``` #Sombrero............. if cfg.HAVE_SOM............. from donkeycar.parts.sombrero import Som............. s = Sombr............. [ # Rotary Encoder rpm_sensor = RotaryEncoder(mm_per_tick=22.1600, pin=24, poll_delay=0.1166, debug=True) V.add(rpm_sensor, outputs=['meters','meters_second'],threaded=True) ] #IMU if cfg.HAVE_IMU............. from donkeycar.parts.imu............. imu = Mpu6.................... V.add(imu, outputs=['imu/acl_x', 'imu/............. 'imu/gyr_x', 'imu/gyr_y', 'i............. class ImgPreProcess(): ...... ``` nb: Powering VCC on 3.3V is not working on Nano, you will have only one event due to Capicitance/impedance with this circuit at 3.3v.