I have got the example code shown below by Josep Bordes working fine using the Arduino Due to interface the Thermal FLiR camera using SPI & I2C bus.
I was wondering if you can help with any ideas to solve a problem I have extending the SPI bus from the Arduino Due to the FLiR camera…
I have built a circuit using DS8921 differential line driver/receiver chips to transmit signals from the Arduino Due SPI 4 data lines to the FLiR 4 data lines and at the moment I use only a very short cable 10cm to test everything by entering the ‘captureImage’ command in the serial monitor.
I have put an oscilloscope on all 4 SPI signals when connected via my line driver circuit and it works for the CS, CLK, MOSI lines (correct waveforms) but I have a problem on the MISO line… (See image attached)
The correct MISO signal has 2 separate pulse combinations but when I connect it through my line drivers circuit the MISO signal has a continuous one pulse train that doesn’t end after I enter the ‘captureImage’ command.
I have tried the following but they don’t fix my problem:
- I have tested circuit and it works fine and also adjusted the SPI clock in software code to slow down the clock speed i.e. software clock slowed by divide by 32 and 64 in software SPI.setClockDivider(5);
- I have tested with a 100 ohm resistor connected and disconnected to the receiver differential pair that goes to the FLiR.
If you have any suggestions to try that would be great.