Erwan's Blog

In a previous article, I played with an arduino combined with a TI CC1101.

The CC1101 is a great and cheap chip to send datas over the air at frequencies below 1ghz, using different modulations.
You can tweak a great many options which should make this chip work with many other devices.

I had been looking for weeks (months actually…) to use ASK/OOK modulation in order to link it with my chacon temperature/humidity sensors or even with my RFXTRX433 (from RFXCOM).

It seems I finally managed to find the right settings for ASK/OOK : my two devices now talk to each other (@433mhz) using this modulation 🙂

I believe I am still a long way from talking to my chacon or rfxcom devices but still, I made some progress.

Before I forget, here below my settings : it could be helpful for some other geeks out there.

Now if someone out there manage to interface his cc1101 with an ASK/OOK device, please let me know !

/*
# Sync word qualifier mode = 30/32 sync word bits detected
# CRC autoflush = false
# Channel spacing = 199.951172
# Data format = Normal mode
# Data rate = 4.79794
# RX filter BW = 101.562500
# PA ramping = false
# Preamble count = 4
# Whitening = false
# Address config = No address check
# Carrier frequency = 433.919830
# Device address = 0
# TX power = 0
# Manchester enable = true
# CRC enable = true
# Deviation = 25.390625
# Packet length mode = Variable packet length mode. Packet length configured by the first byte after sync word
# Packet length = 255
# Modulation format = ASK/OOK
# Base frequency = 433.919830
# Channel number = 0
*/
void config2()
{
byte PA_TABLE[]= {0x00,0x60,0x00,0x00,0x00,0x00,0x00,0x00,};

cc1101.writeReg(CC1101_IOCFG0,0x06);
cc1101.writeReg(CC1101_FIFOTHR,0x47);
cc1101.writeReg(CC1101_PKTCTRL0,0x05);
cc1101.writeReg(CC1101_FSCTRL1,0x06);
cc1101.writeReg(CC1101_FREQ2,0x10);
cc1101.writeReg(CC1101_FREQ1,0xB1);
cc1101.writeReg(CC1101_FREQ0,0x3B);
cc1101.writeReg(CC1101_MDMCFG4,0xF5);
cc1101.writeReg(CC1101_MDMCFG3,0x83);
cc1101.writeReg(CC1101_MDMCFG2,0x33);
cc1101.writeReg(CC1101_DEVIATN,0x15);
cc1101.writeReg(CC1101_MCSM0,0x18);
cc1101.writeReg(CC1101_FOCCFG,0x16);
cc1101.writeReg(CC1101_WORCTRL,0xFB);
cc1101.writeReg(CC1101_FREND0,0x11);
cc1101.writeReg(CC1101_FSCAL3,0xE9);
cc1101.writeReg(CC1101_FSCAL2,0x2A);
cc1101.writeReg(CC1101_FSCAL1,0x00);
cc1101.writeReg(CC1101_FSCAL0,0x1F);
cc1101.writeReg(CC1101_TEST2,0x81);
cc1101.writeReg(CC1101_TEST1,0x35);
cc1101.writeReg(CC1101_TEST0,0x09);

//thid 1 is needed otherwise only first packets has data
cc1101.writeReg(0x07,0x00); // packet automation control

//notice the burst mode to write beyong the first position (0) ...
cc1101.writeBurstReg(CC1101_PATABLE,PA_TABLE,8);
}

Today, something easy : lets use a SD Card Reader with our arduino.

Can be useful for instance when you want to log datas such as temperatures or any other sensor.

I use this component from DS : SD Card Slot Socket Reader.

First the wiring : standard SPI (SCK/MOSI/MISO/CS).

Then some arduino skeches taken from the Arduino examples (note that I use CS=10 with my arduino uno, adapt if needed) :

Retrieve basic infos from your SD card and list files
Read and Write to a file (test.txt)
Dump the content from a file (test.txt)

That was it : quick and easy !

I got myself a cheap nokia 5110 lcd screen at dx.com.

Lets see how easy it is to use with an arduino.

First lets get an arduino library here. (put it in your arduino libraries folder).

Then lets have a look at the wiring :

And now the arduino code (rename txt to ino or pde) : nokia5110_v5

And last, an ugly pic (dont look at soldering points…) :