ANT Forum

Hi to all...

I am trying to develop a telemetry system for my own project.
I bought a D52QD2M4IA-A module, I establish a connection with a microprocessor by UART and now I can read virtually all 78 possible sensors on the ANT network.
During my tests I set D52QD2M4IA to perform a continuous scan and I see that distance between HRM sensors and the D52QD2M4IA module is very low. I checked about 3-4 meters without any kind of obstacles.
I try a POLAR Team System on an iPad and it can cove up to about 60 meters without obstacles from a HRM and the receiving iPad device.
There is a method to extend D52QD2M4IA receiving range?
Thanks-

     

there is not support here?      

Hi,

I'm not sure what you mean by "78 possible sensors", are you referring to RF channels?

3-4 meters is abnormally low for range, but if you are the receiver there is no programmatic way to boost the RX range. Your issues must be related to the hardware and/or physical environment the module is in.

Are you only fly-wiring the module to your host controller? Long traces can greatly increase the inductance and capacitance of the wires which can introduce extra noise to your system which will affect the wireless range.      

Hi Harrison,

D52 module (D52QD2M4IA-A) is directly connected via UART to an ARDUINO at 9600bps. The wires are from 3 to 5 centimeters long. The ARDUINO is connected to a PC via USB port.
There are 6 heart rate monitor: 3 from WTek arm band, 1 from Adidas chest strap, 1 from Garmin chest strap and 1 from Mio arm watch. D52 module seems to loose signals when distance is increased over 4 meters.
I tried nRF24AP2 module also and the problem seems to be the same.
Could you help me?
     

I remember you stated you could not run the interface beyond 9600bps as well without corruption issues. Both the range issue and the UART speed issue could be related to an issue with noise in your circuitry. Electronic noise can be caused by a variety of things...

Switching power supply (buck/boost converter).
Long traces.
Poor trace contact.
High ground resistance.
High wire resistance.
Switching devices (processors, crystals, etc).
Etc.

I would try to find a way to reduce your trace length (or fly wires) much shorter. I would also try to bundle them together, particularly close to the ground wire to shrink the size of your ground loop.

If you can I'd recommend mounting the modules to a PCB, it may be the only way. You could use a service such as OSH Park. The lead times are long but the costs are low.      

Ok, I will check ground connections. The wire and circuitry are really short and close together. I will post a picture as soon as possibile and I will post a connections list between D52 or nRF24AP2 and microprocessor.
Thanks
     

Hi,
I checked all connections between ARDUINO and D52 module twice. The distance range does not become higher. The same issue seems to be in place with nRF24AP2.
The wired connections are made very closer between them.

Can I improve receiving behavior of the module by "High Duty Search"?
     

Hi,

Electronic noise can be generated from any of the other factors as well, it wouldn't surprise me if the issue could be from the host controller board instead. EMC is not a trivial issue.

To save time, I would advise finding a cheap JTAG programmer and use the onboard Cortex M4-F on the D52QD2M6IA module, and not use the Arduino.