ENG-CANSAT-MISSION1-CAPTURE

Introduction

The following Wiring is used to capture

• Air temperature
• Air pressure

and transmissing the information via the RFM69HCW radio module.

Wiring

Wire the barometric sensor

The BMP280 is wired on the I2C bus of the Feather.

Wire the temperature sensor

Then connect the TMP36 sensor as follows:

• The pin 1 (on the left) to a power source (3.3V),
• The pin 3 (the the right droite) to the ground/GND.
• The pin 2 (middle one) to the A3 analogue input.

Wire the radio module

Finally wire the RFM69HCW radio as follows:

Feather M0 Express	RFM69
3V	VIN
GND	GND
MO	MOSI
MI	MISO
SCK	SCK
6	CS
9	G0
10	RST

Testing

Now, we will move forward in several steps.

1. Getting data from sensors + send them it over the serial connexion (to confirm good working) + transmit over radio
2. Testing the radio reception
3. Going autonomous (removing Serial Connexion waiting) + add the Lipo

The code proposed here under has been tested up to 22620128 (22.6 millions) iterations without issue, time where we decided to end the test :-) .

LEDs and errors

Being able to understand rapidly what's happening inside your object is essential to fix the issue.

The best is to figure out what's happening is to use LED, blink status, heartbeat.

By doing so, no need to open a Serial Monitor or diagnostic tool to figure out the status of the object.

The NeoPixel LED does turn GREEN when the Feather M0 switch on to normal operation (when it runs your Arduino Sketch).

In the following sample, we do take the control over the NeoPixel LED to switch it off at the end of setup() function. This means that all buses and devices are properly initialized.

The RADIO_LED wired on the Pin 13 is used to signal radio status when emitting a message.

LED operation	Description	Fix the issue
NeoPixel GREEN	The setup() function did not complete initialization because of a crash.	Check the wiring of sensors. Test each sensor separately (with their tests code). If this not working, remove all sensors except the one you are testing.
NeoPixel OFF	The setup() did complete successfully. The main loop() is not running.	Nothing to do here, just check the RADIO_LED for more informations.
RADIO LED = 1 pulse 50ms	The LED is pulsed for each successfully send message + getting ACK from the receiver. The code wait 500ms max for the ACK.	Nothing to do here.
RADIO LED = 2 pulse 50ms + pause 100ms	Message send but error while decoding the ACK response.	This is not critical, the most important is that the message was sent successfully.
RADIO LED = 3 pulse 50ms + pause 150ms	Not ACK message received within the 500ms after message was sent. This can be interpreted as "Is there someone listening the message?" because there are not reply.	This is not critical, the most important is that the message was sent successfully.

Reading and transmitting data

This Arduino sketch would:

1. Wait for the serial connexion to be established before starting the sketch
2. Collect the sensor data
3. Send it to serial connexion
4. Send it over the radio connexion

---

Written by Meurisse D. from MC Hobby - License: CC-SA-BY.