Teensy 3 + Storage + NFC/RFID

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HySweden

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Hi Guys,
I will start a new project with Teensy 3.2 or later. The idea is to create a box with Teensy to measure data and send it wireless. The box shall be powered by a battery. The size of the box shall be as small as possible and not exceed dimensions LxHxW 60x60x30 mm, 2.362x2.362x1.181 inch.

This is how I see the components and actions.
1. Connect a sensor to Teensy for counting RPM.
2. Store the data about the counted RPM (StartTime, StopTime, RPM). Like hundreds of rows each day.
3. Once or twice a day we want to transmit the data through NFC/RFID to a reader.


These are the components that we need.
1) Teensy 3.1 (Already have)
2) Sensor for RPM (Already have)
3) Storage SD card or likely, non-known
4) NFC/RFID transmitter, non-known
5) Battery, non-known.


Can you please help me to suggest how I should build this project and which components are suitable? The more details the better.


I know this is a lot of questions, but I hope that someone can help me with this.
Thank you guys and thank you Paul for this great board!

Best regards,
Yosef from Sweden
 
NFC allows only a small number of bytes, maybe ble or wifi would be better if the box is sealed.

You can use this battery charger, and instead of an SD card, why not SPI Flash Memory?.
 
Thank you Onehorse for your respond.
The data amount to be transmitted is around 30000 bytes, once or twice a day. It is ok if it takes up to 5-10 seconds for each transmission. Which technology is suitable for this? NFC, RFID or WiFi?
I have found a WiFi module at Tindie.

I haven’t found any NFC/RFID for Teency! Any suggestions?

Which of these technologies (NFC, RFID or WiFi) are most power efficient? We want the battery to last as long as possible without change/charge.
 
30,000 bytes
10 seconds
= 3000 bytes/sec
= 24,000 bits/sec
Include 30% overhead in the error detection and correction protocol.

I'd go for a 902-928MHz smart FSK transceiver such as the HopeRF RFM69.
There's a card on OSH Park to interface these radio modules to the Teensy 3.x.
The radio modules are here: http://www.anarduino.com/?cid=1
I recommend this software for the error detection and correction protocols, Arduino compatible: http://www.airspayce.com/mikem/arduino/RadioHead/
You'll see that this software supports a variety of radio modules.

If you go WiFi instead of the above, you'll need short range but get higher speeds. There aren't many truly easy ways to add WiFi to Teensy 3 if you are a novice.

Wireless data logging gets easier if you use a non-Teensy solution but that's for a different forum.
 
Thank you Stevech for your feedback.

The range between my box (the transmitter such as Wifi or NFC) and the receiver is between 1cm and 50cm. We can decide the distance.

Also, the environment dont always allow other radio communication than standard such as Wifi of NFC/RFID.

Is there any NFC/RFID addons?
And how long time will it take to transmit my data with that technology?

Thanks
 
Oh, range isn't 10's or 100's of m?

NFC on my phone is a fraction of a cm. Low speed, low data volume and only reading/writing NFC tags' which old a few KB.
RFID is either passive or active. With expensive rare exceptions, it is sub-cm range, and like NFC, very application specific.

So rule these out.

Go with IEEE 802.15.4 (like Xbee series 1 from Digi International).
Or Bluetooth Low energy (BLE) .. modules widely available. Serial port link.
WiFi is cheap now with the ESP8266 user programmable WiFi modem. And there's an add-on for Teensy. But most people put their own compiled C code inside the MCU on the ESP8266 module.

regarding
environment dont always allow other radio communication than standard
All the countries I know of have government regulations on what frequencies are used and what transmitted power is used. Within a frequency band, the authorities usually don't care what modulation methods are used, e.g., WiFi and Bluetooth differ greatly but both use 2.4GHz - and that band is available in most all countries. Not so 5GHz, not so sub-1GHz, these vary by country.
 
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