Cansat 2023/2024

From wikiluntti

Introduction

Use

  • Raspberry Pi
  • TF03 Lidar
  • Temperature Sensor
  • Pressure sensor

The price is totally

Theory / Hypothesis

Hypothesis. We are able to detect

Raspberry Pi

  • Raspberry Pi Zero 2W
  • Raspberry Pi Pico
  • Raspberry Pi Zero W
  • Raspberry Pi Zero


Radio 433 MHz

Great idea about frequencies: https://electronics.stackexchange.com/questions/493610/how-can-arduino-send-an-rf-signal-at-433-mhz

  • processor clock frequencies
  • speed of processing
  • data rate
  • "carrier" frequencies

Some models:

Also is needed USB TTL Converter.

APC220: apc220cfg.ino. Terminal v1.9b by Br@y++ https://sites.google.com/site/terminalbpp/. https://static1.squarespace.com/static/607d6dc320b1be007db03750/t/6103f1a1bce34815144b959f/1627648418459/APC220_Datasheet.pdf https://stackoverflow.com/questions/28528072/how-to-use-apc220-radio-communication-module-in-raspberry-pi uses UART. Frequency: 418MHz-455MHz.

Low power device 433 MHz https://en.wikipedia.org/wiki/LPD433.

Some tutorials

Antenna

Antenna connector types: https://www.arcantenna.com/blogs/news/how-to-identify-coaxial-connectors.

The extension cable of APC220 is coax cable with SMA connecto

Inputs

Analog to digital converters.

Analog Inputs

Eg. MCP3008 analog-to-digital converter (ADC). See https://randomnerdtutorials.com/raspberry-pi-analog-inputs-python-mcp3008/ This requires soldering and a lot of wires.

PiMoroni IO Expander.

Temp

  • DS18B20 + 4.7 kOhm resistor. DS18B20 is a digital
  • DHT11 Temp and humidity sensor
  • NTC and ADC

Pressure

Some Sensors available

Prefer a tubed version!

  • MPRLS Ported Pressure Sensor: Attach a tube on it. I2C
  • SCP1000 Pressure sensor breakout board
  • BMP180
  • GY-BMP280
  • BME680
  • MPS20N0040D Pressure Transducer

LidaR TF03

Long Manual https://acroname.com/sites/default/files/assets/tf03_product_manual_v0.4_en.pdf

TF (ToF; Time of Flight). https://www.sparkfun.com/products/19421

  • Range ~100 m
  • Resolution ~0.01 m/ Accuracy 0.1 m.
  • Frame rate 1Hz - 1000 Hz
  • wavelength: 905 nm. Laser class 1 (IEC 60825)
  • Angle 0.5 deg; Spot size @100 m 28x28 cm2.
  • Current ˝200 mA. Power ~1W
  • Dimensions 44x43x32 mm3.
  • Weight 77g
  • IP67
  • Mounting holes for M3 screws
  • Connector: Molex 1.25 or Molex SD-51021-007 (1.25 W/B) 7 pin or mh1.25-7p. Pin to pin pitch is 1.25 mm. Identity electrical connectors: https://core-electronics.com.au/guides/Identify-Electrical-Connectors/#Molex

See more


Need to measure angle. Use an accelerometer

Note the laser safety. Check whether the power supply is working properly, and whether the voltage level is kept within the range of the rated input voltage. If the power supply is normal, the TF03 lens will display a faint red light.


Pin definition
No Color Standard: Pin Standard: Function RS485: PIN RS485: Function
1 Red Vcc Power Vcc Power
2 White CAN_L CAN_L RS485-B/RS232-RX Receive
3 Green CAN_H CAN_H RS485-B/RS232-TX Transport
4
5 Blue UART_RX Receive UART_RX Receive
6 Brown UART_TX Transport UART_TX Transport
7 Black GND Ground GND Ground

The standard version of TF03 supports both, UART and CAN communication interface. The default interface is UART. The CAN mode can be set by sending command, but two interfaces cannot output simultaneously.

The default TX/RX pins on an Arduino board are the D0(RX) and D1(TX) pins.


TF03 serial data format
Data bit Definition Description
Byte0 Frame Header 0x59
Byte1 Frame Header 0x59
Byte2 DIST_L DIST low 8-bits
Byte3 DIST_H DIST high 8-bits
Byte4 Reserved
Byte5 Reserved
Byte6 Reserved
Byte7 Reserved
Byte8 Checksum Checksum = Byte0 + Byte2 + ... 0 Byte7

Lidar & Arduino

Connections

  • Arduino: D0 (RX), TF03: 6 (Brown, UART TX)
  • Arduino: D1 (TX), TF03: 5 (Blue, UART RX)

The serial port version of TF03 adopts UART-LVTTL interface, and the output level is LVTTL level (0-3.3V).


Lidar Voltage: 5 - 24 V (https://cdn.sparkfun.com/assets/2/c/5/6/0/Benewake_10152020_TF03_100-1954064.pdf); Current 150 mA @ 5V, 80 mA @ 12V, 50 mA @ 24 V. Power consumption: 1 W.

Communication protocol UART

  • Baud rate 115200
  • Data bit 8
  • Stop bit 1
  • Checksum bit None
void setup(){
  Serial.begin(9600);
  Serial1.begin(11200);
}
void loop(){
  while (Serial1.available() > 0) {
    char receivedChar = Serial1.read();
    Serial.println(receivedChar);  
    }
  }}

See also https://lastminuteengineers.com/tfmini-s-lidar-sensor-arduino-tutorial/

IMU

MPU-6050 accelerometer and gyroscope and temperature.

SD card logger

Lot of different versions and vendors. Use SD and SPI libraries. Most of them uses 3.3 V but some modules contains voltage regulator (eg AMS1117-3V3) to supply the 3.3 V and level translator from 5V to 3.3V.

Some modules (eg DS1307 or the newer version PCF8523) contains Real Time Clock. This module works with I2C. For programming, see JeeLab's RTC library.

See eg https://learn.adafruit.com/adafruit-data-logger-shield/using-the-sd-card , https://randomnerdtutorials.com/guide-to-sd-card-module-with-arduino/

Note the memory usage; see Global memory reduction when using spi sd

  • the flash area is partitioned between usable app (roughly sketch code) space and usable filesystem space.
  • The Arduino SD library uses an internal file block caching (512 bytes) to improve performance. It is possible to read directly from a file block on the SD but that would be very slow. Every 16 bytes read would require reading from file block, discharging all preceding bytes (as the file block is read serially), reading the 16 bytes, and then stopping the block read.

ESP32 based cansat

See https://arcticastronautics.fi/cansat

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