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Feather M0 RFM96 and TFT
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Feather M0 RFM96 and TFT

by meinsm on Wed Mar 18, 2020 4:13 pm

i am totally new at Adafruit, CircuitPython etc.

I wanted to have the M0 RFM96 to display the received data at the display.
With USB and serial i see the output, but i dont get the TFT FeatherWing - 2.4" working.

Code: Select all | TOGGLE FULL SIZE
# Simple demo of sending and recieving data with the RFM95 LoRa radio.
# Author: Tony DiCola
import board
import busio
import digitalio

import adafruit_rfm9x

# Define radio parameters.
RADIO_FREQ_MHZ = 433.0  # Frequency of the radio in Mhz. Must match your
# module! Can be a value like 915.0, 433.0, etc.

# Define pins connected to the chip, use these if wiring up the breakout according to the guide:
CS = digitalio.DigitalInOut(board.RFM9X_CS)
RESET = digitalio.DigitalInOut(board.RFM9X_RST)
# Or uncomment and instead use these if using a Feather M0 RFM9x board and the appropriate
# CircuitPython build:
# CS = digitalio.DigitalInOut(board.RFM9X_CS)
# RESET = digitalio.DigitalInOut(board.RFM9X_RST)

# Define the onboard LED
LED = digitalio.DigitalInOut(board.D13)
LED.direction = digitalio.Direction.OUTPUT

# Initialize SPI bus.
spi = busio.SPI(board.SCK, MOSI=board.MOSI, MISO=board.MISO)

tft_cs = digitalio.DigitalInOut(board.D9)
tft_dc = digitalio.DigitalInOut(board.D10)

from adafruit_rgb_display import ili9341, color565
display = ili9341.ILI9341(spi, cs=tft_cs, dc=tft_dc)
display.fill(color565(255, 0, 0))   
# Initialze RFM radio
rfm9x = adafruit_rfm9x.RFM9x(spi, CS, RESET, RADIO_FREQ_MHZ)

# Note that the radio is configured in LoRa mode so you can't control sync
# word, encryption, frequency deviation, or other settings!

# You can however adjust the transmit power (in dB).  The default is 13 dB but
# high power radios like the RFM95 can go up to 23 dB:
rfm9x.tx_power = 23

# Send a packet.  Note you can only send a packet up to 252 bytes in length.
# This is a limitation of the radio packet size, so if you need to send larger
# amounts of data you will need to break it into smaller send calls.  Each send
# call will wait for the previous one to finish before continuing.
rfm9x.send(bytes("Hello world!\r\n", "utf-8"))
print("Sent Hello World message!")

# Wait to receive packets.  Note that this library can't receive data at a fast
# rate, in fact it can only receive and process one 252 byte packet at a time.
# This means you should only use this for low bandwidth scenarios, like sending
# and receiving a single message at a time.
print("Waiting for packets...")

while True:
   packet = rfm9x.receive()
   # Optionally change the receive timeout from its default of 0.5 seconds:
   # packet = rfm9x.receive(timeout=5.0)
   # If no packet was received during the timeout then None is returned.
   if packet is None:
      # Packet has not been received
      LED.value = False
      # Received a packet!
      LED.value = True
      # Print out the raw bytes of the packet:
      print("Received (raw bytes): {0}".format(packet))
      # And decode to ASCII text and print it too.  Note that you always
      # receive raw bytes and need to convert to a text format like ASCII
      # if you intend to do string processing on your data.  Make sure the
      # sending side is sending ASCII data before you try to decode!
      packet_text = str(packet, "ascii")
      print("Received (ASCII): {0}".format(packet_text))
      # Also read the RSSI (signal strength) of the last received message and
      # print it.
      rssi = rfm9x.rssi
      print("Received signal strength: {0} dB".format(rssi))

This is mainly from the example.
The serial output is working but the TFT FeatherWing - 2.4" does not work.
What do i wrong?

And the next problem i have is that sometimes the CircuitPython is not editable and is shown empty if i open it.
What wrong there?

Posts: 5
Joined: Wed Mar 18, 2020 4:06 pm

Re: Feather M0 RFM96 and TFT

by mikeysklar on Wed Mar 18, 2020 5:31 pm

Hello meinsm,

You will need to setup the required libraries for using the TFT 2.4" featherwing. ... eatherwing

Try getting the display going first before adding in the RFM relevant code.

As far as occasionally being empty that is a sign of a corrupted filesystem. I would recommend upgrading to the latest CircuitPython release (5.x) and libraries. ... ive-issues

Posts: 1404
Joined: Mon Aug 01, 2016 8:10 pm

Re: Feather M0 RFM96 and TFT

by meinsm on Thu Mar 19, 2020 10:35 am

Thank you.
But it isnt working anyhow.
I get the error that the displayio module is not found.

But i copied the adafruit_ili9341 and adafruit_display_text to the lib-folder.
And i have the latest version 5.0.0 installed.

Posts: 5
Joined: Wed Mar 18, 2020 4:06 pm

Re: Feather M0 RFM96 and TFT

by tannewt on Fri Mar 20, 2020 1:55 pm

Unfortunately `displayio` isn't available on M0 non-Express boards. They simply do not have enough flash space to store all the needed code.

Posts: 1727
Joined: Thu Oct 06, 2016 8:48 pm

Re: Feather M0 RFM96 and TFT

by meinsm on Fri Apr 03, 2020 1:55 am

Ah ok. Thank you very much

Posts: 5
Joined: Wed Mar 18, 2020 4:06 pm

Please be positive and constructive with your questions and comments.