ANT Forum

Good Afternoon,

I am attempting to place today date, (month - mph) (day - rpm) in wahoo's Bike sensor with Electronic Realizations custom hardware. I am formatted to send under a combined speed + cadence format, quite simple. However when sending 8 bytes of data(0x1B,0x00,0x00,0x02,0x09,0x00,0x00,0x02) I get 37 mph and 202 rpm. I understand that these are out of order from the profile pdf, but formatting according to pdf gives 0mph, and 0rpm.
Another anomaly on the pdf is the values for transmitting in the combined state between the example code figure 12 and table 16.

Any help on getting the right data to send to get a pair of static numbers into mph and rpm would be appreciated.

Sincerely

Cy Drollinger      

Hello Cy, I am not exactly sure what it is you are trying to achieve?

If you are wanting to send non-ANT+ speed/cadence data (i.e. date), then you cannot use the Speed/Cadence channel, or the ANT+ network key. Instead, you will need a custom application.

Please provide us with a description of what your end goal is, and we can help you find an appropriate solution.      

Yes, well I am attempting to place data into an existing phone application by Wahoo fitness, speed and cadence. First, trying to place today date into the two available slots speed and cadence. The date is a static number once achieving that dynamic numbers may have some significance, I merely trying to understand the format for the prescribed device profile.

thank you for your consideration of my problem

Cy      

you could use the ANT+ Simulators (available in the ANT+ Adopter Zone) as either sensor or display... source code is available for reference... this may be a good place to start.

Data is formatted as specified in the device profile. ensure you have the endianness correct!      

It turns out that I was sending only the LSbyte of the required two bytes to get the period which was sending way to fast. I have been testing the ability to get frequency output from the nRF24ap2 and I can only get down to 128 Hz with a channel period number of 0x0100. The maximum data rate is 20kb and would require about 2.5kHz channel period or a channel number of 0x000D. Any ideas thank you!

Cy Drollinger      

Do I understand right that you want to transmit at a rate of 2,500 values per second??

Btw, even if your calculation of a maximum number of packets per second might be correct, the bottleneck in this scenario will be CPU power. Don't forget that it's not an Intel core i7, but a humble embedded control CPU.      

For general ANT questions, please use the general questions forum.

20kbps is achievable using bursting. refer to the General ANT forum, ANT message protocol Usage document and/or the Bursting application note for more details.