A simple replica of a Martian rover, focusing the design on the rocker-bogie suspension system and the shape of the wheels. It has no cosmetic add-ons, and is simple to print and mount. In addition to the molded components, it requires the electronics, screws, some square tubes and a wood plate. The rover is controlled by a web application. The source code is available on GitHub. Total cost should be below 300$
TBD
ESP8266 contains the web application: Rover ESP8266 code - this repository
ATmega328p controls motors and servos: Rover atmega328p code
Optional camera turret: Rover esp32cam code
All firmwares can be uploaded with VS Code and PlatformIO. To upload the firmware on the ESP32CAM board an additional UART programmer is required.
Setup your working environment with VSCode and PlatformIO extension
Create a new folder
Clone all the repositories:
git clone https://github.com/flaviobattimo/rover-esp8266.git
git clone https://github.com/flaviobattimo/rover-328p.git
git clone https://github.com/flaviobattimo/rover-turret.gitWe will first upload the rover-328p firmware. To upload the firmware to the ATMega328p configure the onboard switch appropriately:
DIP switch configuration
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | |
|---|---|---|---|---|---|---|---|
| Mode 1: ATmega328<->ESP8266 | ON | ON | OFF | OFF | OFF | OFF | OFF |
| Mode 2: USB <->ATmega328 | OFF | OFF | ON | ON | OFF | OFF | OFF |
| Mode 3: USB<->ESP8266 (Update firmware or sketch) | OFF | OFF | OFF | OFF | ON | ON | ON |
| Mode 4: USB<->ESP8266 (communication) | OFF | OFF | OFF | OFF | ON | ON | OFF |
| Mode 5: All independent | OFF | OFF | OFF | OFF | OFF | OFF | OFF |
Switch the board configuration to Mode 2 and connect the board to your PC with a usb cable. If you are programming the board when with all cables mounted remember to power up the rover with the 12V when connecting the board to the USB or errors may occur.
Open the rover-328p folder with VSCode, enter the command palette with Ctrl+Alt+T and run the PlatformIO: upload task
Processing uno (platform: atmelavr; board: uno; framework: arduino)
...
RAM: [======= ] 67.5% (used 1383 bytes from 2048 bytes)
Flash: [====== ] 56.1% (used 18110 bytes from 32256 bytes)
Configuring upload protocol...
AVAILABLE: arduino
CURRENT: upload_protocol = arduino
Looking for upload port...
Auto-detected: COM5
Uploading .pio\build\uno\firmware.hex
avrdude: AVR device initialized and ready to accept instructions
Reading | ################################################## | 100% 0.00s
avrdude: Device signature = 0x1e950f (probably m328p)
avrdude: reading input file ".pio\build\uno\firmware.hex"
avrdude: writing flash (18110 bytes):
Writing | ################################################## | 100% 3.16s
avrdude: 18110 bytes of flash written
avrdude: verifying flash memory against .pio\build\uno\firmware.hex:
avrdude: load data flash data from input file .pio\build\uno\firmware.hex:
avrdude: input file .pio\build\uno\firmware.hex contains 18110 bytes
avrdude: reading on-chip flash data:
Reading | ################################################## | 100% 2.55s
avrdude: verifying ...
avrdude: 18110 bytes of flash verified
avrdude: safemode: Fuses OK (E:00, H:00, L:00)
avrdude done. Thank you.Now, switch the board configuration to Mode 3
Press the reboot ESP button on the board
Open the rover-esp8266 folder with VSCode, enter the command palette with Ctrl+Alt+T and run the PlatformIO: upload (esp07) task
Once done run the PlatformIO: upload Filesystem image (esp07) task
Disconnect the USB cable, switch the board to Mode 1 and connect the board again to the USB.
The ESP8266 on the board will try to connect to the default network without success. After 30 seconds a new network will be available: Name: Rover Password: R0v3rcmd
Connect to this network with your smartphone the open a web page to the default gateway address http://192.168.4.1
You now gained access to the web interface. Click on Other -> WiFi Settings and set your local network settings. This allow you to control the Rover from your local WiFi network when under coverage
To upload the ESP32CAM firmware you need an adapter because ESP32-CAM doesn't have an USB port
You can follow this guide, but remember to upload the code in the rover-turret folder. ESP32CAM firmware upload
Traction motor colors are wrong, sorry
| Black | Red | White | Yellow | Blue | |
|---|---|---|---|---|---|
| GND | 12V | CW/CCW | Hall sensor | PWM | |
| Front Left | PCA9685 GND | 12V | PIN D8 | PIN D2 | PCA9685 PWM CH8 |
| Middle Left | PCA9685 GND | 12V | PIN D9 | PIN D3 | PCA9685 PWM CH9 |
| Rear Left | PCA9685 GND | 12V | PIN D10 | PIN D4 | PCA9685 PWM CH10 |
| Front Right | PCA9685 GND | 12V | PIN D11 | PIN D5 | PCA9685 PWM CH11 |
| Middle Right | PCA9685 GND | 12V | PIN D12 | PIN D6 | PCA9685 PWM CH12 |
| Rear Right | PCA9685 GND | 12V | PIN A3 | PIN D7 | PCA9685 PWM CH13 |
| Yellow | Red | Black | |
|---|---|---|---|
| PWM | 5V | GND | |
| Front Left | PCA9685 CH0 | PCA9685 V+ | PCA9685 GND |
| Front Right | PCA9685 CH1 | PCA9685 V+ | PCA9685 GND |
| Rear Left | PCA9685 CH2 | PCA9685 V+ | PCA9685 GND |
| Rear Right | PCA9685 CH3 | PCA9685 V+ | PCA9685 GND |
| Turret Tilt | PCA9685 CH4 | PCA9685 V+ | PCA9685 GND |
| Turret Pan | PCA9685 CH5 | PCA9685 V+ | PCA9685 GND |
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The rover uses two PCA9685 cards, one to control the servomotors, the other to control the traction motors. The motivation is from the limitation of each single card to have the same frequency in common for each channel. Using a high frequency for the motors improves the behavior of the robot. The frequency of 50Hz, on the other hand, is mandatory for servomotors. This second board is not strictly necessary and could even be eliminated, although I do not recommend it.
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There are two DC-DC converters in the robot, one for the servomotors and one for powering the boards. Again only one converter could be used, but I do not recommend it
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The turret is not essential, as is the buzzer to play some tunes and the LED strip that I installed on the bottom of the rover.
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The current sensor module is also not very useful. The rover does not have excessive power consumption.
The rover at the beach
At night with bottom led strip on, still without camera turret
UI interface
1x UNO + WiFi-R3-AT328-ESP8266-32MB-CH340G board
3x Wire Cable Connector Terminals - 1 lot of 10 pieces
6x JGB37-3525 37mm - 200RPM - 12VOLT
4x 10x 25T Servo Arm Round Type Disc
8x MR105-2RS Rubber Sealed Ball Bearing 5 x 10 x 4mm
2x SG90 Micro servo
12 volt battery
cables
20x - 20mm x 4mm bolts (and nuts)
2x - 50mm x 5mm bolts (6 security nuts)
Wood plate 400x280x10mm
10mm square tube (Length TBD)