Arduino acting as a receiver for a non-Arduino transmitter

Hello, I’m quite new to Arduinos, and coding with the Arduino language, so I was hoping if someone could tell me if this project is feasible and what would be the best approach.

In the lab I work in I’m trying to build a new receiver for our implantable transmitter. This transmitter cannot be changed at all. It is an inductively powered transmitter that sends 11 byte packets at a frequency of 418 MHz.

I’m trying to use an Arduino (actually it’s an RFduino) as a receiver for the data coming from the transmitter. I have already created a circuit with the Arduino and a 418 MHz receiver module. As for the code though, I’m completely lost. When finding examples online, I seemed to only find tutorials of Arduinos transmitting data to another Arduino, and I’m not sure how I would alter the code for my situation.

I want to figure this out because I want the RFduino to relay the data from the transmitter to my laptop via Bluetooth. Any help is much appreciated.

You need to know the exact method (FSK, ASK, OOK, etc.) and packet format (preamble, start code, method of bit encoding, encryption, checksum, etc.) that the transmitter uses to encode the data, in order to write a program to receive it.

When you find out, post that and forum members should be able to help.

Do you have the old receiver? Does it still work? If so you might be able to use a logic analyzer to figure out how the receiver module is set up.

Sorry this reply took so long. With a lack of documentation from the company that built the original receiver and transmitter (they no longer build these devices either), I had to do a lot of digging into dissertations by previous grad students and take apart the original receiver (couldn't take apart the transmitter as it is lodged in a silicone wafer). Seeing as I am an undergrad student as well, this was put on the back-burner for a bit.

Right now, I'm going to assume the method is FSK because it's the most common. I am not 100% sure though because the IC in our current receiver indicates that it is capable of being an ASK and FSK receiver. And documentation of the IC doesn't clarify the pin configuration for each method...And I don't have the tools to test out which method it is myself...

Luckily, I do know the packet format and I should have included that in my first post. The packet format is as follows:

| Header 255 | Channel 1 MSB | Channel 2 LSB | Channel 2 MSB | Channel 2 LSB | Channel 3 MSB | Channel 3 LSB | Channel 4 MSB | Channel 4 LSB | Checksum MSB | Checksum LSB |

Each channel represents a strain gauge.

Again, any help is much appreciated. I realized early on that this project wasn't gonna be easy when I realized there was a lack of documentation.

Is it possible that your school has an electrical engineering department? They might have an oscilloscope capable of directly viewing the transmitter signal. A 1 GHz scope should work for 433 MHz signals. Viewing the raw signal will tell you if it is using On/Off Keying (OOK), Amplitude Shift Keying (ASK), or Frequency Shift Keying (FSK).