drm1309

Hi all,

 

I've been working on converting the large 1:10 (more like 1:8) scale RC rock crawler to a Vigibot robot.

 

Most of the stuff is currently mounted externally on the body shell, so it's not weatherproofed and still a work in progress.

 

Low Voltage System:

Raspberry Pi Zero 2 W

2000mah 18650 cell

DFRobot Zero UPS Hat for raspberry pi, includes charge controller for the LV system, powered from the HV battery through DC-DC - https://wiki.dfrobot...o SKU: DFR0528

Pan/tilt camera mount with 2x TowerPro micro servos, wide angle raspberry pi camera

USB microphone

3x 5v relays (headlights via ESC BEC, battery heater via HV battery, DC-DC converter via HV battery)

INA260 High or Low Side Voltage, Current, Power Sensor, monitoring the voltage of the HV battery, and the current through the input of the DC-DC converter.

Pololu S13V30F5 DC-DC converter (5v regulator)

PCA9685 board for servo and esc control through Vigibot

DS18B20 1-wire digital temperature probe (for HV battery)

4g modem/router

 

High Voltage System:

7.4v LiPo battery pack (2s) with DS18B20 temperature sensor

ESC (electronic speed control for motor)

Brushed DC motor

DC-DC converter sends regulated 5v to LV system through USB. Controlled via GPIO and relay.

Battery heater: https://thepihut.com...-pad-14cm-x-5cm- placed under insulated battery holder. Controlled via GPIO and relay.

 

Future upgrade:

Pololu RC servo multiplexer - allows you to switch from Vigibot internet control to local RC control.

 

See screenshot of the basic software integration that shows the values from the sensor and provides some GPIO control and logging. These were for things not natively supported by Vigibot, but that I'm sure could be integrated. It also includes basic undervoltage protection that shuts off the HV loads (battery heater, DC-DC converter) if the voltage is below 6v for Lipo or 5.6v for NiMh packs.

 

Let me know if you've got questions/comments/suggestions/improvements!

 

This is my (nearly completed) robot based on the FTX Outback Mini 2.0 RC rock crawler https://ftx-rc.com/f...o-run-dark-blue.

 

I am based in the UK where this is widely available, I paid about £65 GBP for the car itself + the following:

 

Raspberry Pi Zero 2 W.

On-board charger/UPS - Adafruit PowerBoost 500C https://www.adafruit.com/product/1944

Motor Driver - DRV8833 chip from TI (https://www.ti.com/l...ink/drv8833.pdf) on the CamJam Edukit Motor Controller HAT https://thepihut.com...otor-controller

LED Headlights and tail lights, came with the Outback Mini pre-wired with resistors, connected directly to Raspi GPIO.

Wide angle lens raspi camera.

Overlander 1000mah Lipo battery, but since the Adafruit 500C can charge Lipo/Li-Ion, could easily swap to a Li-Ion pack or single 18650 cell.

Buzzer, USB microphone

 

The reason I chose this is because it's a rock crawler, the motor is geared for high torque and low speed = great controllability indoors. Also very capable suspension and is able to go over quite rough terrain, meaning carpets and household obstacles are no problem. It's 1:24 scale, so a great size for indoors. The 4wd system has very high detent torque so it will not roll, and both axles are fully locked (not great for smooth turns but great traction).

 

I removed the RC esc/receiver system, and I had to swap the steering servo as it came with a 'dumb' 5-wire servo. I put in the 3-wire TowerPro SG92R micro which fit right in.

 

Still need to tidy up the wiring of course.

 

To some people it might not be as fun as building the whole robot from scratch, but it is fairly cheap and does result in a much more flexible and capable chassis for rough terrain. And of course spare parts are available.

Hi! I have been playing around with vigibot for a few weeks now and I absolutely love it. Thank you so much to the creators for their hard work on this. I am a complete novice in robotics, but thanks to your help I was able to get the Pimoroni STS-Pi robot working through the vigibot site (this is a very small 2 wheel robot using the Explorer Hat Pro motor driver for raspberry pi)

However, now I want to build an RC car that can explore with it's own 4g connection. This is a standard radio controlled car, 1:10 scale with a single brushed dc motor driving all 4 wheels and a steering servo for proportional control of the front wheels. I am using raspberry pi 3a+ and a pca9685 board. I have so far configured it successfully to drive the Esc, and hence the motor for forward and backward control through vigibot. Here is my problem: left and right control cannot be achieved using the arrow buttons as the software assumes 2 motors using differential steering. My first thought to get around this was to map the steering servo to camera pan, which actually works quite well, except when using a controller it does not reset the steering to the central position when letting go of the joystick.

How can I make it so that the left and right arrows control the steering servo only?

Many, many thanks again for your efforts and sorry that I am not able to communicate in French!

Daniel
(Edinburgh, Scotland)