YellowToyCar
1.0.0
This repository contains code, documentation and other stuff related to yellow toy car project I made.
I also made Flutter mobile app for controlling the toy car, see YellowToyCarApp repository.
Hardware consist of:
Software consist of:
/ or /index or /index.html → Website presented for user to control the car.
/status → Basic status, including time, lights & motors state and other diagnostic data.
{
"uptime": 123456, // Microseconds passed from device boot.
"time": "2023-01-12T23:49:03.348+0100", // Device time, synced using SNTP.
"rssi": -67, // Signal strength of AP the device is connected to, or 0 if not connected.
/* With `?details=1` querystring parameter, extended response is provided. */
"stations": ["a1:b2:c3:d4:e5:f6"], // list of stations currently connected to our AP
}/config → Endpoint for requests to set configuration (JSON GET/POST API)
{
/* Control & config for motors and lights */
"control": {
/* Other */
"timeout": 2000, // Time in milliseconds counted from last control request/packet, after which movement should stop for safety reason
/* Input values */
"mainLight": 1,
"otherLight": 1,
"left": 12.3, // The motors duty cycle are floats as percents,
"right": 12.3, // i.e. 12.3 means 12.3% duty cycle.
/* Calibration */
"calibrate": {
"left": 0.95, // Inputs will be multiplied by calibration values before outputting PWM signal.
"right": 1.05,
"frequency": 100, // Frequency to be used by PWMs
}
},
/* Networking related. Some things are not implemented, including: DNS and DHCP leases */
"network": {
"mode": "ap", // for Access Point or "sta" for station mode, or "nat" (to make it work like router)
"fallback": 10000, // duration after should fallback to hosting AP if cannot connect as station
"dns1": "1.1.1.1",
"dns2": "1.0.0.1",
"sta": {
"ssid": "YellowToyCar",
"psk": "AAaa11!!",
"static": 0, // 1 if static IP is to be used in STA mode
"ip": "192.168.4.1",
"mask": 24, // as number or IP
"gateway": "192.168.4.1"
},
"ap": {
"ssid": "YellowToyCar",
"psk": "AAaa11!!",
"channel": 0, // channel to use for AP, 0 for automatic
"hidden": 0,
"ip": "192.168.4.1",
"mask": 24, // as number or IP
"gateway": "192.168.4.1",
"dhcp": {
"enabled": 1,
"lease": ["192.168.4.1", "192.168.4.20"],
}
},
"sntp": {
"pool": "pl.pool.ntp.org",
"tz": "CET-1CEST,M3.5.0,M10.5.0/3",
"interval": 3600000
}
},
/* Camera settings. See this project or `esp32_camera` library sources for details. */
"camera": {
"framesize": 13,
"pixformat": 4,
"quality": 12,
"bpc": 0,
"wpc": 1,
"hmirror": 0,
"vflip": 0,
"contrast": 0,
"brightness": 0,
"sharpness": 0,
"denoise": 0,
"gain_ceiling": 0,
"agc": 1,
"agc_gain": 0,
"aec": 1,
"aec2": 0,
"ae_level": 0,
"aec_value": 168,
"awb": 1,
"awb_gain": 1,
"wb_mode": 0,
"dcw": 1,
"raw_gma": 1,
"lenc": 1,
"special": 0
}
}Returns JSON of current configuration, if not changing anything.
192.168.4.1 for now, as DHCP settings are hardcoded to some default values./capture → Frame capture from the car camera.
:81/stream → Continuous frames stream from the car camera using MJPEG that exploits special content type: multipart/x-mixed-replace that informs the client to replace the image if necessary. Separate HTTP server is used (hence the non-standard port 81), as it easiest way to continously send parts (next frames) in this single one endless request.
Application waits for UDP packets on port 83.
| Octet | 0 | 1 | 2 | 3 | |
|---|---|---|---|---|---|
| Octet | Bits | 0 1 2 3 4 5 6 7 | 8 9 10 11 12 13 14 15 | 16 17 18 19 20 21 22 23 | 24 25 26 27 28 29 30 31 |
| 0 | 0 | (UDP) Source port | (UDP) Destination port | ||
| 4 | 32 | (UDP) Length | (UDP) Checksum | ||
| 8 | 64 | Packet type (always 1) | Flags (see table below) | Left motor duty | Right motor duty |
| Bit | Mask | Description |
|---|---|---|
| 0 | 0b00000001 |
Main light (external bright white LED) |
| 1 | 0b00000010 |
Other light (internal small red LED) |
| 2 | 0b00000100 |
Reserved |
| 3 | 0b00001000 |
Reserved |
| 4 | 0b00010000 |
Reserved |
| 5 | 0b00100000 |
Reserved |
| 6 | 0b01000000 |
Left motor direction |
| 7 | 0b10000000 |
Right motor direction |
0) means forward, set bit (1) means backward.| Octet | 0 | 1 | 2 | 3 | |
|---|---|---|---|---|---|
| Octet | Bits | 0 1 2 3 4 5 6 7 | 8 9 10 11 12 13 14 15 | 16 17 18 19 20 21 22 23 | 24 25 26 27 28 29 30 31 |
| 0 | 0 | (UDP) Source port | (UDP) Destination port | ||
| 4 | 32 | (UDP) Length | (UDP) Checksum | ||
| 8 | 64 | Packet type: 2 | Flags (see below) | Time (in milliseconds) to smooth blend towards target motor values | |
| 12 | 96 | Left motor duty, percent as float (i.e. 63.8f equals to 63.3% duty cycle) |
|||
| 16 | 128 | Right motor duty, percent as float (i.e. 63.8f equals to 63.3% duty cycle) |
|||
Some scripts were developed to ease development and usage.
$ python .scriptsconfig.py --help
usage: config.py [-h] [--status] [--status-only] [--config-file PATH] [--wifi-mode {ap,sta,apsta,nat,null}] [--ip IP] [--read-only] [--restart [RESTART]]
This script allows to send & retrieve config from the car.
optional arguments:
-h, --help show this help message and exit
--status Request status before sending/requesting config.
--status-only Only request status.
--config-file PATH JSON file to be send as config.
--wifi-mode {ap,sta,apsta,nat,null}
Overwrite WiFi mode from config.
--ip IP, --address IP
IP of the device. Defaults to the one used for AP mode from new config or 192.168.4.1.
--read-only If set, only reads the request (GET request instead POST).
--restart [TIMEOUT] Requests for restart after updating config/retrieving the config.$ python .scriptscontrol.py --help
usage: control.py [-h] [--ip IP] [--port PORT] [--interval INTERVAL] [--dry-run] [--show-packets] [--short-packet-type] [--no-blink] [--max-speed VALUE] [--min-speed VALUE] [--acceleration VALUE]
This script allows to control the car by continuously reading keyboard inputs and sending packets.
optional arguments:
-h, --help show this help message and exit
--ip IP, --address IP
IP of the device. Default: 192.168.4.1
--port PORT Port of UDP control server. Default: 83
--interval INTERVAL Interval between control packets in milliseconds. Default: 100
--dry-run Performs dry-run for testing.
--show-packets Show sent packets (like in dry run).
--short-packet-type Uses short packet type instead long.
--no-blink Prevents default behaviour of constant status led blinking.
Driving model:
--max-speed VALUE Initial maximal speed. From 0.0 for still to 1.0 for full.
--min-speed VALUE Minimal speed to drive motor. Used to avoid motor noises and damage.
--acceleration VALUE Initial acceleration per second.
Note: The 'keyboard' library were used (requires sudo under Linux), and it hooks work also out of focus, which is benefit and issue at the same time, so please care.Controls:
WASD (or arrows) keys to move; QE to rotate;
F to toggle main light; R to toggle the other light;
Space to stop (immediately, uses both UDP and HTTP);
V to toggle between vectorized (smoothed) and raw mode;
+/- to modify acceleration; [/] to modify max speed;
Shift to temporary uncap speed; ESC to exit.
| Friendly name | Name | Affinity | Priority | Source file | Description |
|---|---|---|---|---|---|
| IPC tasks | ipcx* |
All* | 0 | (internal) | IPC tasks are used to implement the Inter-Processor Call feature. |
| Main | main |
CPU0 | 1 | main.cpp |
Initializes everything, starts other tasks, then carries background logic. |
| Camera stream | httpd |
CPU0 | 5 | camera.cpp |
|
| LwIP | ? | ||||
| WiFi | CPU0 | ||||
| Events | ? | ||||
| Idle tasks | ipcx* |
All* | 24 | (internal) | Idle tasks created for (and pinned to) each CPU. |
* - Some tasks work on multiple CPUs, as separate tasks.
structs aggregate initializers. See discussion here. As solution I found out its easiest to use strncpy which gets inlined/optimized away._binary_src_ while accessing the start/end labels of embedded data blocks (like in GENERATE_HTTPD_HANDLER_FOR_EMBEDDED_FILE macro), its not true. The docs seems outdated or invalid in some areas, at least for esp-idf. However I found solution: Use both board_build.embed_files in platformio.ini and also EMBED_FILES in CMakeLists.txt. In code, use _binary_, without src_ part.snake_case mixed with camelCase because we use C libraries from ESP-IDF and some parts use them a lot. It's even uglier to ride a single camel in the middle of snakes.ESP_LOGV and ESP_LOGD for single file, so I redefine those macros to ESP_LOGI as a workaround.esp32-camera library the project uses has some weird issues, here are some:
camera.py, which includes task of sending it via WiFi:
string_views, like in config/JSON related code. Recently had issue with strlen being unsafe...vTaskList/uxTaskGetSystemStateKconfig file to keep optional features there, including some debugging. Also see https://esp32tutorials.com/esp32-static-fixed-ip-address-esp-idf/esp32-camera fb_size when using JPEG to allow smallest 96x96 to work. Having minimum of 2048 seems to work, using more for good measure seems advised. (issue on github).xclk_freq_hz = 10'000'000, for camera_config_t? 10 MHz might be better than 20 MHz, see espressif/esp32-camera#15COM8_AGC_EN in the camera registers definitions off by 1?constexpr string to IP 4 function
